10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

☒	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the quarterly period ended	June 30, 2021

or

☐	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
	For the Transition Period from                    to

Commission File No. 001-36567

Westlake Chemical Partners LP

(Exact name of registrant as specified in its charter)

Delaware	32-0436529
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)

2801 Post Oak Boulevard, Suite 600

Houston, Texas 77056

(Address of principal executive offices, including zip code)

(713) 585-2900

(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common units representing limited partnership interests	WLKP	The New York Stock Exchange

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     Yes   x     No   ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).     Yes   x     No   ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See definitions of "large accelerated filer," "accelerated filer", "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act:

Large accelerated filer	¨	Accelerated filer	x
Non-accelerated filer	¨	Smaller reporting company	☐
		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ¨  

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act)     Yes   ☐     No   x

The registrant had 35,204,561 common units outstanding as of July 28, 2021.

TABLE OF CONTENTS

Item	Page
PART I. FINANCIAL INFORMATION
1) Financial Statements	1
2) Management's Discussion and Analysis of Financial Condition and Results of Operations	15
3) Quantitative and Qualitative Disclosures about Market Risk	26
4) Controls and Procedures	26
PART II. OTHER INFORMATION
1) Legal Proceedings	26
1A) Risk Factors	27
6) Exhibits	27

PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED BALANCE SHEETS

(Unaudited)

	June 30, 2021		December 31, 2020
	(in thousands of dollars, except unit amounts)
ASSETS
Current assets
Cash and cash equivalents	$	17,665	$	17,154
Receivable under the Investment Management Agreement—Westlake Chemical Corporation ("Westlake")	222,249		123,228
Accounts receivable, net—Westlake	66,948		108,028
Accounts receivable, net—third parties	24,962		11,029
Inventories	4,929		3,474
Prepaid expenses and other current assets	61		392
Total current assets	336,814		263,305
Property, plant and equipment, net	1,030,016		1,050,677
Goodwill	5,814		5,814
Deferred charges and other assets, net	29,111		36,692
Total assets	$	1,401,755	$	1,356,488
LIABILITIES
Current liabilities
Accounts payable—Westlake	$	20,134	$	7,855
Accounts payable—third parties	12,435		13,131
Accrued and other liabilities	16,084		18,768
Total current liabilities	48,653		39,754
Long-term debt payable to Westlake	399,674		399,674
Deferred income taxes	1,634		1,542
Other liabilities	36		381
Total liabilities	449,997		441,351
Commitments and contingencies (Note 12)
EQUITY
Common unitholders—publicly and privately held (21,082,331 and 21,076,673 units    issued and outstanding at June 30, 2021 and December 31, 2020, respectively)	476,076		471,701
Common unitholder—Westlake (14,122,230 and 14,122,230 units issued and outstanding    at June 30, 2021 and December 31, 2020, respectively)	51,103		48,270
General partner—Westlake	(242,572)		(242,572)
Total Westlake Chemical Partners LP partners' capital	284,607		277,399
Noncontrolling interest in Westlake Chemical OpCo LP ("OpCo")	667,151		637,738
Total equity	951,758		915,137
Total liabilities and equity	$	1,401,755	$	1,356,488

The accompanying notes are an integral part of the consolidated financial statements.

1

WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
	(in thousands of dollars, except unit amounts and per unit data)
Revenue
Net sales—Westlake	$	240,956	$	227,431	$	460,759	$	442,259
Net co-product, ethylene and other sales—third parties	81,273		11,069		129,677		46,790
Total net sales	322,229		238,500		590,436		489,049
Cost of sales	191,200		148,470		371,708		295,471
Gross profit	131,029		90,030		218,728		193,578
Selling, general and administrative expenses	8,269		6,139		16,942		12,335
Income from operations	122,760		83,891		201,786		181,243
Other income (expense)
Interest expense—Westlake	(2,224)		(3,431)		(4,460)		(7,381)
Other income, net	21		123		28		708
Income before income taxes	120,557		80,583		197,354		174,570
Income tax provision	263		206		438		423
Net income	120,294		80,377		196,916		174,147
Less: Net income attributable to noncontrolling interest in OpCo	95,195		65,517		156,671		141,540
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$	25,099	$	14,860	$	40,245	$	32,607
Net income per limited partner unit attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Common units	$	0.71	$	0.43	$	1.14	$	0.93
Weighted average limited partner units outstanding (basic and diluted)
Common units—publicly and privately held	21,079,657		21,072,315		21,078,173		21,072,315
Common units—Westlake	14,122,230		14,122,230		14,122,230		14,122,230

The accompanying notes are an integral part of the consolidated financial statements.

2

WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY

(Unaudited)

		Partnership
		Common Unitholders— Public and Privately Held		Common Unitholder— Westlake		General Partner— Westlake		Noncontrolling Interests in OpCo		Total
	(in thousands of dollars)
Balance at December 31, 2020		$	471,701	$	48,270	$	(242,572)	$	637,738	$	915,137
Net income		9,069		6,077		—		61,476		76,622
Quarterly distribution to unitholders		(9,936)		(6,657)		—		—		(16,593)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake		—		—		—		(62,058)		(62,058)
Balance at March 31, 2021		$	470,834	$	47,690	$	(242,572)	$	637,156	$	913,108
Net income		15,029		10,070		—		95,195		120,294
Units issued for vested phantom units		149		—		—		—		149
Quarterly distribution to unitholders		(9,936)		(6,657)		—		—		(16,593)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake		—		—		—		(65,200)		(65,200)
Balance at June 30, 2021		$	476,076	$	51,103	$	(242,572)	$	667,151	$	951,758

The accompanying notes are an integral part of the consolidated financial statements.

3

WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY

(Unaudited)

		Partnership
		Common Unitholders— Public and Privately Held		Common Unitholder— Westlake		General Partner— Westlake		Noncontrolling Interests in OpCo		Total
	(in thousands of dollars)
Balance at December 31, 2019		$	471,736	$	48,350	$	(242,572)	$	674,621	$	952,135
Net income		10,626		7,121		—		76,023		93,770
Quarterly distribution to unitholders		(9,934)		(6,657)		—		—		(16,591)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake		—		—		—		(79,223)		(79,223)
Balance at March 31, 2020		$	472,428	$	48,814	$	(242,572)	$	671,421	$	950,091
Net income		8,897		5,963		—		65,517		80,377
Quarterly distributions to unitholders		(9,933)		(6,657)		—		—		(16,590)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake		—		—		—		(78,025)		(78,025)
Balance at June 30, 2020		$	471,392	$	48,120	$	(242,572)	$	658,913	$	935,853

The accompanying notes are an integral part of the consolidated financial statements.

4

WESTLAKE CHEMICAL PARTNERS LP

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited)

	Six Months Ended June 30,
	2021		2020
	(in thousands of dollars)
Cash flows from operating activities
Net income	$	196,916	$	174,147
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	56,244		51,844
Loss from disposition of property, plant and equipment	1,391		446
Other gains, net	759		(310)
Changes in operating assets and liabilities
Accounts receivable—third parties	(14,600)		3,235
Net accounts receivable—Westlake	53,191		(8,890)
Inventories	(1,455)		955
Prepaid expenses and other current assets	331		405
Accounts payable	653		1,207
Accrued and other liabilities	(3,140)		998
Other, net	(3,172)		(318)
Net cash provided by operating activities	287,118		223,719
Cash flows from investing activities
Additions to property, plant and equipment	(27,289)		(20,595)
Maturities of investments with Westlake under the Investment Management Agreement	83,000		181,000
Investments with Westlake under the Investment Management Agreement	(182,000)		(190,000)
Other	126		—
Net cash used for investing activities	(126,163)		(29,595)
Cash flows from financing activities
Quarterly distributions to noncontrolling interest retained in OpCo by Westlake	(127,258)		(157,248)
Quarterly distributions to unitholders	(33,186)		(33,181)
Net cash used for financing activities	(160,444)		(190,429)
Net increase in cash and cash equivalents	511		3,695
Cash and cash equivalents at beginning of period	17,154		19,923
Cash and cash equivalents at end of period	$	17,665	$	23,618

The accompanying notes are an integral part of the consolidated financial statements.

5

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

1. Description of Business and Basis of Presentation

Description of Business

Westlake Chemical Partners LP (the "Partnership") is a Delaware limited partnership formed in March 2014 to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests.

In connection with the IPO, the Partnership acquired a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo") and a 100% interest in Westlake Chemical OpCo GP LLC ("OpCo GP"), which is the general partner of OpCo. OpCo owns three ethylene production facilities and one common carrier ethylene pipeline (collectively, the "Contributed Assets"). Since the IPO, the Partnership has periodically purchased additional limited partner interest in OpCo. Most recently, on March 29, 2019, the Partnership purchased an additional 4.5% newly-issued limited partner interest in OpCo for approximately $201,445, resulting in an aggregate 22.8% limited partner interest in OpCo, effective January 1, 2019. The remaining 77.2% limited partner interest in OpCo is owned by Westlake Chemical Corporation.

Basis of Presentation

The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), filed with the SEC on March 2, 2021. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2020.

References to "Westlake" refer collectively to Westlake Chemical Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

The Partnership holds a 22.8% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 77.2% limited partner interest in OpCo is owned directly by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. Westlake's retained interest of 77.2% is recorded as noncontrolling interest in the Partnership's consolidated financial statements.

In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of June 30, 2021, its results of operations for the three and six months ended June 30, 2021 and 2020 and the changes in its cash position for the six months ended June 30, 2021 and 2020.

Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2021 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates.

6

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

The COVID pandemic resulted in widespread adverse impacts on the global economy in 2020. The Partnership has not experienced significant disruptions to its business operations in 2020 or during the six months ended June 30, 2021 and does not expect significant disruptions to its business operations resulting from COVID-19. However, the impact that COVID-19 will have on the Partnership's financial condition, results of operations and cash flows cannot be estimated with certainty at this time as it will depend on future developments, including, among others, the timing and logistics with respect to the distribution of vaccines globally and the efficacy of the available vaccines (including with respect to the more recent variants of COVID-19) and other treatments, the ultimate duration of the pandemic, geographic spread and severity of the virus, the consequences of governmental and other measures designed to prevent the spread of the virus, the impact on the operation of OpCo's facilities, Westlake, customers, suppliers and other third parties and the timing and extent to which normal economic and operating conditions resume.

Recent Accounting Pronouncements

Reference Rate Reform (ASU No. 2020-04)

In March 2020, the FASB issued an accounting standards update to provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this update are effective for all entities as of March 12, 2020 through December 31, 2022 and are not expected to have a material impact on the Partnership's consolidated financial position, results of operations and cash flows.

2. Accounts Receivable—Third Parties

Accounts receivable—third parties consist of the following:

	June 30, 2021		December 31, 2020
Trade customers	$	25,908	$	11,344
Allowance for credit losses	(982)		(315)
	24,926		11,029
Other receivables	36		—
Accounts receivable, net—third parties	$	24,962	$	11,029

3. Inventories

Inventories consist of the following:

	June 30, 2021		December 31, 2020
Finished products	$	4,566	$	3,157
Feedstock, additives and chemicals	363		317
Inventories	$	4,929	$	3,474

4. Property, Plant and Equipment

Depreciation expense on property, plant and equipment of $22,983 and $22,714 is included in cost of sales in the consolidated statements of operations for the three months ended June 30, 2021 and 2020, respectively. Depreciation expense on property, plant and equipment of $45,785 and $45,467 is included in cost of sales in the consolidated statements of operations for the six months ended June 30, 2021 and 2020, respectively.

5. Deferred Charges and Other Assets

Amortization expense on other assets of $5,719 and $3,099 is included in costs of sales in the consolidated statements of operations for the three months ended June 30, 2021 and 2020, respectively. Amortization expense on other assets of $10,459 and $6,377 is included in costs of sales in the consolidated statements of operations for the six months ended June 30, 2021 and 2020, respectively.

7

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

6. Distributions and Net Income Per Limited Partner Unit

On August 2, 2021, the board of directors of Westlake Chemical Partners GP LLC ("Westlake GP"), the Partnership's general partner, declared a quarterly cash distribution for the three months ended June 30, 2021 of $0.4714 per unit. This distribution is payable on August 26, 2021 to unitholders of record as of August 12, 2021.

Distributions are declared subsequent to quarter end; therefore, the table below represents total cash distributions declared from earnings of the related periods pertaining to such distributions.

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Net income attributable to the Partnership	$	25,099	$	14,860	$	40,245	$	32,607
Less:
Limited partners' distribution declared on common units	16,595		16,590		33,188		33,181
Net income in excess of distribution (distribution in excess of net income)	$	8,504	$	(1,730)	$	7,057	$	(574)

Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statements of changes in equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

	Three Months Ended June 30, 2021
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,595	$	—	$	16,595
Net income in excess of distribution	8,504		—		8,504
Net income	$	25,099	$	—	$	25,099
Weighted average units outstanding:
Basic and diluted	35,201,887				35,201,887
Net income per limited partner unit:
Basic and diluted	$	0.71

8

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

	Three Months Ended June 30, 2020
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,590	$	—	$	16,590
Distribution in excess of net income	(1,730)		—		(1,730)
Net income	$	14,860	$	—	$	14,860
Weighted average units outstanding:
Basic and diluted	35,194,545				35,194,545
Net income per limited partner unit:
Basic and diluted	$	0.43

	Six Months Ended June 30, 2021
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,188	$	—	$	33,188
Net income in excess of distribution	7,057		—		7,057
Net income	$	40,245	$	—	$	40,245
Weighted average units outstanding:
Basic and diluted	35,200,403				35,200,403
Net income per limited partner unit:
Basic and diluted	$	1.14

	Six Months Ended June 30, 2020
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,181	$	—	$	33,181
Distribution in excess of net income	(574)		—		(574)
Net income	$	32,607	$	—	$	32,607
Weighted average units outstanding:
Basic and diluted	35,194,545				35,194,545
Net income per limited partner unit:
Basic and diluted	$	0.93

The amended Partnership Agreement provides that the Partnership will distribute cash each quarter to all the unitholders, pro rata, until each unit has received a distribution of $1.2938. If cash distributions to the Partnership's unitholders exceed $1.2938 per common unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations:

	Marginal Percentage Interest in Distributions
Total Quarterly Distribution Per Unit	Unitholders		IDR Holders
Above $1.2938 up to $1.4063	85.0	%	15.0	%
Above $1.4063 up to $1.6875	75.0	%	25.0	%
Above $1.6875	50.0	%	50.0	%

9

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

The Partnership's distribution for the three months ended June 30, 2021 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights.

Distribution Per Common Unit

Distributions per common unit for the three and six months ended June 30, 2021 and 2020 were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Distributions per common unit	$	0.4714	$	0.4714	$	0.9428	$	0.9428

7. Partners' Equity

On October 4, 2018, the Partnership and Westlake Chemical Partners GP LLC, the general partner of the Partnership, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell the Partnership's common units, from time to time, up to an aggregate offering amount of $50,000. The Equity Distribution Agreement was amended on February 28, 2020 to reference a new shelf registration for utilization under this agreement. No common units were issued under this program as of June 30, 2021.

On March 29, 2019, the Partnership completed the issuance and sale of 2,940,818 common units at a price of $21.40 per unit through a private placement. TTWF LP, Westlake's principal stockholder and a related party, acquired 1,401,869 common units out of 2,940,818 common units issued in the private placement.

8. Related Party Transactions

The Partnership and OpCo regularly enter into related party transactions with Westlake. See below for a description of transactions with related parties.

Sales to Related Parties

OpCo sells ethylene to Westlake under the Ethylene Sales Agreement. Additionally, the Partnership and OpCo from time to time provide other services or products for which it charges Westlake a fee.

Sales to related parties were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Net sales—Westlake	$	240,956	$	227,431	$	460,759	$	442,259

10

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

During June 2021, OpCo's Petro 1 facility experienced an outage, which resulted in a force majeure event under the Ethylene Sales Agreement. In addition, OpCo declared a force majeure in February 2021 due to the severe winter storm. As a result of these force majeure events, the Partnership updated its estimate of OpCo's 2021 anticipated production as of June 30, 2021. The buyer deficiency fee is measured based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. Based upon this change in estimate of OpCo's 2021 anticipated production, the Partnership has recognized buyer deficiency fees and shortfall fees of $8,742 and $18,420 during the three and six months ended June 30, 2021, respectively. The buyer deficiency fees and shortfall fees are classified as a component of net sales.

During 2020, the Lake Charles Petro 1 and Petro 2 facilities were impacted by Hurricanes Laura and Delta, which resulted in force majeure events under the Ethylene Sales Agreement. As a result of the force majeure events, the Partnership recognized a buyer deficiency fee of $69,555 as a component of net sales in 2020. Payment for the buyer deficiency fee was received by the Partnership in January 2021.

Cost of Sales from Related Parties

Charges for goods and services purchased by the Partnership and OpCo from Westlake and included in cost of sales relate primarily to feedstock purchased under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement.

Charges from related parties in cost of sales were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Feedstock purchased from Westlake and included in cost of sales	$	100,979	$	69,324	$	183,095	$	128,962
Other charges from Westlake and included in cost of sales	27,466		23,898		59,308		47,998
Total	$	128,445	$	93,222	$	242,403	$	176,960

Services from Related Parties Included in Selling, General and Administrative Expenses

Charges for services purchased by the Partnership from Westlake and included in selling, general and administrative expenses primarily relate to services Westlake performs on behalf of the Partnership under the Omnibus Agreement, including the Partnership's finance, legal, information technology, human resources, communication, ethics and compliance and other administrative functions.

Charges from related parties included within selling, general and administrative expenses were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Services received from Westlake and included in selling, general and administrative expenses	$	7,000	$	5,698	$	14,912	$	10,813

Goods and Services from Related Parties Capitalized as Assets

Charges for goods and services purchased by the Partnership and OpCo from Westlake which were capitalized as assets relate primarily to the services of Westlake employees under the Services and Secondment Agreement.

Charges from related parties for goods and services capitalized as assets were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Goods and services purchased from Westlake and capitalized as assets	$	533	$	384	$	936	$	864

11

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

Receivable under the Investment Management Agreement

On August 1, 2017, the Partnership, OpCo and Westlake executed an investment management agreement (the "Investment Management Agreement") that authorized Westlake to invest the Partnership's and OpCo's excess cash with Westlake for a term of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. Accrued interest of $77 and $56 was included in the receivable under the Investment Management Agreement balance at June 30, 2021 and December 31, 2020, respectively. Total interest earned related to the Investment Management Agreement was $77 and $219 for the three months ended June 30, 2021 and 2020, respectively, and $145 and $807 for the six months ended June 30, 2021 and 2020, respectively.

The Partnership's receivable under the Investment Management Agreement was as follows:

	June 30, 2021		December 31, 2020
Receivable under the Investment Management Agreement	$	222,249	$	123,228

Accounts Receivable from Related Parties

The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake and the buyer deficiency fee and shortfall fee recognized under the Ethylene Sales Agreement, as discussed above under "Sales to Related Parties." The buyer deficiency fee and shortfall fee recognized in the six months ended June 30, 2021are scheduled to be received by the Partnership after the end of 2021.

The Partnership's accounts receivable from Westlake were as follows:

	June 30, 2021		December 31, 2020
Accounts receivable—Westlake	$	66,948	$	108,028

Accounts Payable to Related Parties

The Partnership's accounts payable to Westlake result primarily from feedstock purchases under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement and the Omnibus Agreement.

The related party accounts payable balances were as follows:

	June 30, 2021		December 31, 2020
Accounts payable—Westlake	$	20,134	$	7,855

Related Party Leases

OpCo is obligated to Westlake under various long-term and short-term noncancelable operating leases, primarily related to rail car leases and land. Operating lease rentals paid to Westlake for such leases were $608 and $726 for the three months ended June 30, 2021 and 2020, respectively, and $1,295 and $1,396 for the six months ended June 30, 2021 and 2020, respectively, and reflected in other charges from Westlake that are included in cost of sales.

OpCo has two site lease agreements with Westlake, each of which has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year.

12

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

Debt Payable to Related Parties

See Note 9 for a description of related party debt payable balances.

Interest on related party debt payable balances for the three months ended June 30, 2021 and 2020 was $2,224 and $3,431, respectively. Interest on related party debt payable is presented as interest expense—Westlake in the consolidated statements of operations. At June 30, 2021 and December 31, 2020, accrued interest on related party debt was $2,224 and $2,336, respectively, and is reflected as a component of accrued liabilities in the consolidated balance sheets.

Debt payable to related parties was as follows:

	June 30, 2021		December 31, 2020
Long-term debt payable to Westlake	$	399,674	$	399,674

Major Customer and Concentration of Credit Risk

During the three months ended June 30, 2021 and 2020, Westlake accounted for approximately 74.8% and 95.4%, respectively, of the Partnership's net sales. During the six months ended June 30, 2021 and 2020, Westlake accounted for approximately 78.0% and 90.4%, respectively, of the Partnership's net sales.

Other

See Note 7 above for an additional related party transaction.

9. Long-term Debt Payable to Westlake

Long-term debt payable to Westlake consists of the following:

	June 30, 2021		December 31, 2020
OpCo Revolver (variable interest rate of London Interbank Offered Rate ("LIBOR") plus 2.0%, scheduled maturity of September 25, 2023)	$	22,619	$	22,619
MLP Revolver (variable interest rate of LIBOR plus 2.0%, scheduled maturity of March 19, 2023)	377,055		377,055
	$	399,674	$	399,674

The weighted average interest rate on all long-term debt was 2.2% at June 30, 2021 and December 31, 2020.

As of June 30, 2021, the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver.

10. Fair Value Measurements

The Partnership reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). Under the accounting guidance for fair value measurements, inputs used to measure fair value are classified in one of three levels:

Level 1: Quoted market prices in active markets for identical assets or liabilities.

Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.

Level 3: Unobservable inputs that are not corroborated by market data.

13

WESTLAKE CHEMICAL PARTNERS LP

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS—Continued

(Unaudited)

(in thousands of dollars, except unit amounts and per unit data)

The Partnership has financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt payable to Westlake, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Partnership's long-term debt at June 30, 2021 and December 31, 2020 are summarized in the table below. The Partnership's long-term debt includes the OpCo Revolver and the MLP Revolver at June 30, 2021. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate.

	June 30, 2021				December 31, 2020
	Carrying Value		Fair Value		Carrying Value		Fair Value
OpCo Revolver	$	22,619	$	22,924	$	22,619	$	23,301
MLP Revolver	377,055		379,868		377,055		383,284

11. Supplemental Information

Accrued and Other Liabilities

Accrued and other liabilities were $16,084 and $18,768 at June 30, 2021 and December 31, 2020, respectively. Accrued taxes, accrued maintenance expense and accrued capital expenditures, which are components of accrued liabilities, were $3,925, $3,025 and $2,823, respectively, at June 30, 2021 and $6,207, $3,905 and $2,286, respectively, at December 31, 2020. No other component of accrued and other liabilities was more than five percent of total current liabilities.

Non-cash Investing Activity

The non-cash investing activities related to accruals for capital expenditures were $669 and $182 for the six months ended June 30, 2021 and 2020, respectively.

12. Commitments and Contingencies

The Partnership is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require the Partnership to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. These laws include the federal Clean Air Act, the federal Water Pollution Control Act, the Resource Conservation and Recovery Act ("RCRA"), the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), the Toxic Substances Control Act and various other federal, state and local laws and regulations. Under CERCLA, an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because the Partnership's production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Partnership. Westlake will indemnify the Partnership for liabilities that occurred or existed prior to August 4, 2014.

The Partnership is involved in various legal proceedings incidental to the conduct of its business. The Partnership does not believe that any of these legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows.

14

Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations

This Management's Discussion and Analysis of Financial Condition and Results of Operations section should be read in conjunction with the accompanying consolidated financial statements and the notes thereto and the consolidated financial statements and notes thereto included in Westlake Chemical Partners LP's annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), as filed with the SEC on March 2, 2021. Unless otherwise indicated, references in this report to "we," "our," "us" or like terms, refer to Westlake Chemical Partners LP (the "Partnership"), Westlake Chemical OpCo LP ("OpCo") and Westlake Chemical OpCo GP LLC ("OpCo GP"). References to "Westlake" refer to Westlake Chemical Corporation and its consolidated subsidiaries other than the Partnership, OpCo GP and OpCo. The following discussion contains forward-looking statements. Please read "Forward-Looking Statements" for a discussion of limitations inherent in such statements.

Partnership Overview

We are a Delaware limited partnership formed by Westlake to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, we closed our initial public offering (the "IPO") of 12,937,500 common units. In connection with the IPO, we acquired a 10.6% interest in OpCo and a 100% interest in OpCo GP, which is the general partner of OpCo. On April 29, 2015, we purchased an additional 2.7% newly-issued limited partner interest in OpCo, resulting in an aggregate 13.3% limited partner interest in OpCo, effective April 1, 2015. The 12,686,115 subordinated units of the Partnership, all of which were previously owned by Westlake, were converted into common units of the Partnership on August 30, 2017. On September 29, 2017, we completed a secondary public offering of 5,175,000 common units and purchased an additional 5.0% newly-issued limited partner interest in OpCo, resulting in an aggregate 18.3% limited partner interest in OpCo, effective July 1, 2017. On March 29, 2019, we completed a private placement of 2,940,818 common units and used the net proceeds to purchase an additional 4.5% interest in OpCo, effective January 1, 2019, resulting in us owning an aggregate 22.8% limited partner interest in OpCo.

Our sole revenue generating asset is our 22.8% limited partner interest in OpCo, a limited partnership formed by Westlake and us in anticipation of the IPO to own and operate an ethylene production business. We control OpCo through our ownership of its general partner. Westlake retains the remaining 77.2% limited partner interest in OpCo as well as a significant interest in us through its ownership of our general partner, 40.1% of our limited partner units (consisting of 14,122,230 common units) and our incentive distribution rights. OpCo's assets include (1) two ethylene production facilities ("Petro 1" and "Petro 2" and, collectively, "Lake Charles Olefins") at Westlake's Lake Charles, Louisiana site; (2) one ethylene production facility ("Calvert City Olefins") at Westlake's Calvert City, Kentucky site; and (3) a 200-mile common carrier ethylene pipeline (the "Longview Pipeline") that runs from Mont Belvieu, Texas to Westlake's Longview, Texas facility.

How We Generate Revenue

We generate revenue primarily by selling ethylene and the resulting co-products we produce. OpCo and Westlake have entered into an ethylene sales agreement (the "Ethylene Sales Agreement") pursuant to which we generate a substantial majority of our revenue. The Ethylene Sales Agreement is a long-term, fee-based agreement with a minimum purchase commitment and includes variable pricing based on OpCo's actual feedstock and natural gas costs and estimated other costs of producing ethylene (including OpCo's estimated operating costs and a five-year average of OpCo's expected future maintenance capital expenditures and other turnaround expenditures based on OpCo's planned ethylene production capacity for the year), plus a fixed margin per pound of $0.10 less revenue from co-products sales. Pursuant to the Ethylene Sales Agreement, Westlake's obligation to pay for the annual minimum commitment (95% of OpCo's budgeted ethylene production), which is measured on an annual basis, is not reduced for the first 45 days of a force majeure event, but is reduced for the portion of a force majeure event extending beyond the 45th day. In the event of a force majeure event, we recognize buyer deficiency fees representing fixed margin and unavoided operating and maintenance capital expenditures and maintenance expenses associated with ethylene that OpCo would have produced and is not expected to be produced based on anticipated production. Payment for the buyer deficiency fee is scheduled to be received by the Partnership after the conclusion of the year.

Westlake has an option to take 95% of volumes in excess of the minimum commitment on an annual basis under the Ethylene Sales Agreement if we produce more than our planned production. Under the Ethylene Sales Agreement, the price for the sale of such excess ethylene to Westlake is based on a formula similar to that used for the minimum purchase commitment, with the exception of certain fixed costs. In addition, under the Ethylene Sales Agreement, if production costs billed to Westlake on an annual basis are less than 95% of the actual production costs incurred by OpCo during the contract year, OpCo is entitled to recover the shortfall in such production costs (proportionate to the volume sold to Westlake) in the subsequent year ("Shortfall"). The Shortfall is generally recognized during the period in which the related operating, maintenance or turnaround activities occur.

15

Operating Expenses, Maintenance Capital Expenditures and Turnaround Costs

Our management seeks to maximize the profitability of our operations by effectively managing operating expenses, maintenance capital expenditures and turnaround costs. Our operating expenses are comprised primarily of feedstock costs and natural gas, labor expenses (including contractor services), utility costs (other than natural gas) and turnaround and maintenance expenses. With the exception of feedstock, including natural gas, and utilities-related expenses, operating expenses generally remain relatively stable across broad ranges of production volumes but can fluctuate from period to period depending on the circumstances, particularly maintenance and turnaround activities. Our maintenance capital expenditures and turnaround costs are comprised primarily of maintenance of our ethylene production facilities and the amortization of capitalized turnaround costs. These capital expenditures relate to the maintenance and integrity of our facilities. We capitalize the costs of major maintenance activities, or turnarounds, and amortize the costs over the period until the next planned turnaround of the affected facility.

Operating expenses, maintenance capital expenditures and turnaround costs are built into the price per pound of ethylene charged to Westlake under the Ethylene Sales Agreement. Because the expenses other than feedstock costs and natural gas are based on forecasted amounts and remain a fixed component of the price per pound of ethylene sold under the Ethylene Sales Agreement for any given 12-month period, our ability to manage operating expenses, maintenance expenditures and turnaround cost may directly affect our profitability and cash flows. The impact on profitability is partially mitigated by the fact that we generally recognize any Shortfall as revenue in the period such costs and expenses are incurred. We seek to manage our operating and maintenance expenses on our ethylene production facilities by scheduling maintenance and turnarounds over time to avoid significant variability in our operating margins and minimize the impact on our cash flows, without compromising our commitment to safety and environmental stewardship. In addition, we reserve cash on an annual basis from what we would otherwise distribute to minimize the impact of turnaround costs in the year of incurrence. The purchase price under the Ethylene Sales Agreement is not designed to cover capital expenditures for expansions.

MLP Distributable Cash Flow and EBITDA

The body of accounting principles generally accepted in the United States is commonly referred to as "GAAP." For this purpose, a non-GAAP financial measure is generally defined by the Securities and Exchange Commission ("SEC") as a numerical measure of a registrant's historical or future financial performance, financial position or cash flows that (1) excludes amounts, or is subject to adjustments that have the effect of excluding amounts, that are included in the most directly comparable measure calculated and presented in accordance with GAAP in the statement of income, balance sheet or statement of cash flows (or equivalent statements) of the registrant; or (2) includes amounts, or is subject to adjustments that have the effect of including amounts, that are excluded from the most directly comparable measure so calculated and presented. We use the non-GAAP measures of MLP distributable cash flow and EBITDA to analyze our performance. We define distributable cash flow as net income plus depreciation, amortization and disposition of property, plant and equipment, less contributions for turnaround reserves, maintenance capital expenditures and mark-to-market adjustment on derivative contracts. We define MLP distributable cash flow as distributable cash flow less distributable cash flow attributable to Westlake's noncontrolling interest in OpCo and distributions attributable to the incentive distribution rights holder. MLP distributable cash flow does not reflect changes in working capital balances. We define EBITDA as net income before interest expense, income taxes, depreciation and amortization. We use each of MLP distributable cash flow and EBITDA to analyze our performance. Fees for a buyer deficiency and Shortfall are included in net income in the periods in which they are recognized. MLP distributable cash flow and EBITDA are non-GAAP supplemental financial measures that management and external users of our consolidated financial statements, such as industry analysts, investors, lenders and rating agencies, may use to assess our operating performance as compared to other publicly-traded partnerships; our ability to incur and service debt and fund capital expenditures; and the viability of acquisitions and other capital expenditure projects and the returns on investment of various investment opportunities.

MLP distributable cash flow is not a substitute for the GAAP measures of net income and net cash provided by operating activities. MLP distributable cash flow has important limitations as an analytical tool because it excludes some but not all items that affect net income and net cash provided by operating activities. EBITDA is not a substitute for the GAAP measures of net income, income from operations and net cash provided by operating activities. In addition, it should be noted that companies calculate EBITDA differently and, therefore, EBITDA as presented for us may not be comparable to EBITDA reported by other companies. EBITDA has material limitations as a performance measure because it excludes interest expense, depreciation and amortization, and income taxes. Reconciliations for each of MLP distributable cash flow and EBITDA are included in the "Results of Operations" section below.

16

Significant Developments Affecting Industry Conditions and Our Business

COVID-19, Industry Conditions and Our Business

On March 11, 2020, the World Health Organization declared the ongoing coronavirus (COVID-19) outbreak a pandemic and recommended containment and mitigation measures worldwide. The pandemic has resulted in widespread adverse impacts on the global economy and on our employees, customers and suppliers. We have not experienced significant disruptions to our business operations and do not expect to experience significant disruptions to our business operations resulting from COVID-19, primarily due to the fact that 95% of our production is sold to Westlake on a take-or-pay contract.

Force Majeure Events

During June 2021, OpCo's Petro 1 facility experienced an outage, which resulted in a force majeure event under the Ethylene Sales Agreement. In addition, OpCo declared a force majeure in February 2021 due to the severe winter storm. As a result of these force majeure events, the Partnership updated its estimate of OpCo's 2021 anticipated production as of June 30, 2021. The buyer deficiency fee is measured based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. Based upon this change in estimate of OpCo's 2021 anticipated production, the Partnership has recognized buyer deficiency fees and Shortfall of $8.7 million and $18.4 million during the three and six months ended June 30, 2021, respectively. The buyer deficiency fees and Shortfall are classified as a component of net sales.

17

Results of Operations

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
	(dollars in thousands)
Revenue
Net sales—Westlake	$	240,956	$	227,431	$	460,759	$	442,259
Net co-product, ethylene and other sales—third parties	81,273		11,069		129,677		46,790
Total net sales	322,229		238,500		590,436		489,049
Cost of sales	191,200		148,470		371,708		295,471
Gross profit	131,029		90,030		218,728		193,578
Selling, general and administrative expenses	8,269		6,139		16,942		12,335
Income from operations	122,760		83,891		201,786		181,243
Other income (expense)
Interest expense—Westlake	(2,224)		(3,431)		(4,460)		(7,381)
Other income, net	21		123		28		708
Income before income taxes	120,557		80,583		197,354		174,570
Income tax provision	263		206		438		423
Net income	120,294		80,377		196,916		174,147
Less: Net income attributable to noncontrolling interest in OpCo	95,195		65,517		156,671		141,540
Net income attributable to Westlake Chemical Partners LP	$	25,099	$	14,860	$	40,245	$	32,607
MLP distributable cash flow (1)	$	25,538	$	16,855	$	41,783	$	35,192
EBITDA (2)	$	151,483	$	109,827	$	258,058	$	233,795
____________
(1) See "Reconciliation of MLP Distributable Cash Flow to Net Income and Net Cash Provided by Operating Activities" below.
(2) See "Reconciliation of EBITDA to Net Income, Income from Operations and Net Cash Provided by Operating Activities" below.

	Three Months Ended June 30, 2021				Six Months Ended June 30, 2021
	Average Sales Price		Volume		Average Sales Price		Volume
Product sales prices and volume percentage change from prior-year period	+30.5	%	+1.0	%	+25.4	%	-8.4	%
	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Average industry prices (1)
Ethane (cents/lb)	8.7		6.4		8.4		5.6
Propane (cents/lb)	20.7		9.6		21.0		9.2
Ethylene (cents/lb) (2)	43.0		11.0		44.0		13.4

_____________

(1)Industry pricing data was obtained through IHS Markit ("IHS"). We have not independently verified the data.

(2)Represents average North American spot prices of ethylene over the period as reported by IHS.

18

Reconciliation of MLP Distributable Cash Flow to Net Income and Net Cash Provided by Operating Activities

The following table presents reconciliations of MLP distributable cash flow to net income and net cash provided by operating activities, the most directly comparable GAAP financial measures, for each of the periods indicated.

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
	(dollars in thousands)
Net cash provided by operating activities	$	131,710	$	112,758	$	287,118	$	223,719
Loss from disposition of fixed assets	(32)		(349)		(1,391)		(446)
Changes in operating assets and liabilities and other	(11,384)		(32,032)		(88,811)		(49,126)
Net Income	120,294		80,377		196,916		174,147
Add:
Depreciation, amortization and disposition of property, plant and equipment	28,734		26,164		57,632		52,291
Mark-to-market adjustment loss (gain) on derivative contracts	—		704		—		(1,787)
Less:
Contribution to turnaround reserves	(12,463)		(9,884)		(24,795)		(19,807)
Maintenance capital expenditures	(14,344)		(8,228)		(26,087)		(19,349)
Distributable cash flow attributable to noncontrolling interest in OpCo	(96,683)		(72,278)		(161,883)		(150,303)
MLP distributable cash flow	$	25,538	$	16,855	$	41,783	$	35,192

Reconciliation of EBITDA to Net Income, Income from Operations and Net Cash Provided by Operating Activities

The following table presents reconciliations of EBITDA to net income, income from operations and net cash provided by operating activities, the most directly comparable GAAP financial measures, for each of the periods indicated.

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
	(dollars in thousands)
Net cash provided by operating activities	$	131,710	$	112,758	$	287,118	$	223,719
Loss from disposition of fixed assets	(32)		(349)		(1,391)		(446)
Changes in operating assets and liabilities and other	(11,384)		(32,032)		(88,811)		(49,126)
Net Income	120,294		80,377		196,916		174,147
Less:
Other income, net	21		123		28		708
Interest expense	(2,224)		(3,431)		(4,460)		(7,381)
Provision for income taxes	(263)		(206)		(438)		(423)
Income from operations	122,760		83,891		201,786		181,243
Add:
Depreciation and amortization	28,702		25,813		56,244		51,844
Other income, net	21		123		28		708
EBITDA	$	151,483	$	109,827	$	258,058	$	233,795

19

Summary

For the quarter ended June 30, 2021, net income was $120.3 million on net sales of $322.2 million. This represents an increase in net income of $39.9 million as compared to net income of $80.4 million on net sales of $238.5 million for the quarter ended June 30, 2020. Net income attributable to the Partnership for the second quarter of 2021 was $25.1 million as compared to $14.9 million for the second quarter of 2020, an increase of $10.2 million. Net income and net income attributable to the Partnership for the second quarter of 2021 as compared to the second quarter of 2020 were higher primarily due to increased sales prices and volumes to third parties and the buyer deficiency fee and Shortfall totaling $8.7 million per the terms of the Ethylene Sales Agreement with Westlake in the second quarter of 2021 due to the force majeure event in June 2021, partially offset by increased ethane feedstock and natural gas costs. Net sales for the second quarter of 2021 increased by $83.7 million as compared to net sales for the second quarter of 2020, mainly due to higher sales prices and volumes to third parties and higher sales price to Westlake per the terms of the Ethylene Sales Agreement, as well as the buyer deficiency fee and Shortfall during the second quarter of 2021. Income from operations was $122.8 million for the second quarter of 2021 as compared to $83.9 million for the second quarter of 2020. Income from operations for the second quarter of 2021 increased mainly as a result of increased sales prices and volumes to third parties and the buyer deficiency fee and Shortfall recognized during the period, partially offset by increased ethane feedstock costs, natural gas costs and selling general and administrative expenses, as compared to the second quarter of 2020.

For the six months ended June 30, 2021, net income was $196.9 million on net sales of $590.4 million. This represents an increase in net income of $22.8 million as compared to net income of $174.1 million on net sales of $489.0 million for the six months ended June 30, 2020. Net income attributable to the Partnership for the six months ended June 30, 2021 was $40.2 million as compared to $32.6 million for the six months ended June 30, 2020, an increase of $7.6 million. Net income and net income attributable to the Partnership for the six months ended June 30, 2021 as compared to the six months ended June 30, 2020 were higher primarily due to higher sales prices to Westlake per the terms of the Ethylene Sales Agreement, higher prices and volumes to third parties and the buyer deficiency fee and Shortfall totaling $18.4 million recognized during the period, partially offset by increased ethane feedstock and natural gas costs as well lower sales volumes to Westlake. Net sales for the six months ended June 30, 2021 increased by $101.4 million as compared to net sales for the six months ended June 30, 2020, mainly due to higher sales prices and volumes to third parties and higher sales price to Westlake per the terms of the Ethylene Sales Agreement, as well as the buyer deficiency fee and Shortfall recognized during the six months ended June 30, 2021, partially offset by lower sales volumes to Westlake during the six months ended June 30, 2021. Income from operations was $201.8 million for the six months ended June 30, 2021 as compared to $181.2 million for the six months ended June 30, 2020. Income from operations for the six months ended June 30, 2021 increased mainly as a result of increased sales prices and volumes for ethylene to third parties and the buyer deficiency fee and Shortfall recognized during the period, partially offset by increased ethane feedstock costs, natural gas costs and selling general and administrative expenses as well lower sales volumes to Westlake as compared to the six months ended June 30, 2020.

RESULTS OF OPERATIONS

Second Quarter 2021 Compared with Second Quarter 2020

Net Sales. Total net sales increased by $83.7 million, or 35.1%, to $322.2 million in the second quarter of 2021 from $238.5 million in the second quarter of 2020. The increase in net sales in the second quarter of 2021 was primarily due to higher sales prices and volumes to third parties and higher sales price to Westlake per the terms of the Ethylene Sales Agreement and the buyer deficiency fee and Shortfall recognized during the period. The average sales price in the second quarter of 2021 contributed to a 30.5% increase in net sales, primarily due to higher ethylene sales prices to third parties and Westlake per the terms of the Ethylene Sales Agreement.

Gross Profit. Gross profit increased to $131.0 million for the second quarter of 2021 from $90.0 million for the second quarter of 2020. The gross profit margin in the second quarter of 2021 was 40.7%, as compared to 37.7% for the second quarter of 2020. The second quarter 2021 gross profit margin was higher mainly due to higher prices and volumes for ethylene sold to third parties and the buyer deficiency fee and Shortfall recognized during the period, partially offset by higher ethane feedstock and natural gas costs in the second quarter of 2021.

Selling, General and Administrative Expenses. Selling, general and administrative expenses increased by $2.2 million, or 36.1%, to $8.3 million in the second quarter of 2021 as compared to $6.1 million in the second quarter of 2020. The increase in the second quarter of 2021 was mainly attributable to increased service costs and allowance for doubtful accounts as compared to the second quarter of 2020.

Interest Expense. Interest expense decreased by $1.2 million to $2.2 million in the second quarter of 2021 from $3.4 million in the second quarter of 2020, largely due to a lower average interest rate on debt.

20

MLP Distributable Cash Flow. MLP distributable cash flow increased by $8.6 million to $25.5 million in the second quarter of 2021 from $16.9 million in the second quarter of 2020. The increase in the second quarter of 2021, as compared to the prior-year period, was primarily attributable to the higher earnings at OpCo, partially offset by increased turnaround reserves and higher maintenance expense.

EBITDA. EBITDA increased by $41.7 million to $151.5 million in the second quarter of 2021 from $109.8 million in the second quarter of 2020. The increase, as compared to the prior-year period, was primarily due to higher sales prices and volumes to third parties, and the buyer deficiency fee and Shortfall recognized during the period, partially offset by higher ethane feedstock and natural gas costs.

Six Months Ended June 30, 2021 Compared with Six Months Ended June 30, 2020

Net Sales. Total net sales increased by $101.4 million, or 20.7%, to $590.4 million in the six months ended June 30, 2021 from $489.0 million in the six months ended June 30, 2020. The increase in net sales in the six months ended June 30, 2021 was primarily due to higher sales prices and volumes to third parties and higher sales price to Westlake per the terms of the Ethylene Sales Agreement, and the buyer deficiency fee and Shortfall recognized during the period, partially offset by lower sales volumes to Westlake during the six months ended June 30, 2021. The average sales price in the six months ended June 30, 2021 contributed to a 25.4% increase in net sales, primarily due to higher ethylene sales prices to third parties and to Westlake per the terms of the Ethylene Sales Agreement. The lower sales volume contributed to a 8.4% decrease in net sales in the six months ended June 30, 2021 compared to the six months ended June 30, 2020. The decrease in sales volumes for the six months ended June 30, 2021 was primarily due to the force majeure events during the period that impacted OpCo's production facilities.

Gross Profit. Gross profit increased to $218.7 million for the six months ended June 30, 2021 from $193.6 million for the six months ended June 30, 2020. The gross profit margin in the six months ended June 30, 2021 was 37.0%, as compared to 39.6% for the six months ended June 30, 2020. The six months ended June 30, 2021, gross profit margin was lower mainly due to increased ethane feedstock and natural gas costs, partially offset by higher prices for ethylene sold to third parties and the buyer deficiency fee and Shortfall recognized during the period compared to the six months ended June 30, 2020.

Selling, General and Administrative Expenses. Selling, general and administrative expenses increased by $4.6 million, or 37.4%, to $16.9 million in the six months ended June 30, 2021 as compared to $12.3 million in the six months ended June 30, 2020. The increase in the six months ended June 30, 2021 was mainly attributable to higher service costs as compared to the six months ended June 30, 2020.

Interest Expense. Interest expense decreased by $2.9 million to $4.5 million in the six months ended June 30, 2021 from $7.4 million in the six months ended June 30, 2020, largely due to a lower average interest rate on debt.

MLP Distributable Cash Flow. MLP distributable cash flow increased by $6.6 million to $41.8 million in the six months ended June 30, 2021 from $35.2 million in the six months ended June 30, 2020. The increase in the six months ended June 30, 2021, as compared to the prior-year period, was primarily attributable to the higher earnings at OpCo, partially offset by increased turnaround reserves and higher maintenance expense.

EBITDA. EBITDA increased by $24.3 million to $258.1 million in the six months ended June 30, 2021 from $233.8 million in the six months ended June 30, 2020. The increase, as compared to the prior-year period, was primarily due to higher sales prices and volumes for ethylene sold to third parties and the buyer deficiency fee and Shortfall recognized during the period, partially offset by lower sales volumes to Westlake as a result of force majeure events and higher ethane feedstock and natural gas costs in the six months ended June 30, 2021.

CASH FLOW DISCUSSION FOR THE SIX MONTHS ENDED JUNE 30, 2021 AND 2020

Operating Activities

Operating activities provided cash of $287.1 million in the first six months of 2021 compared to cash provided by operating activities of $223.7 million in the first six months of 2020. The $63.4 million increase in cash flows from operating activities was mainly due to an increase in cash provided for working capital and income from operations during the six months ended June 30, 2021 as compared to the prior-year period. Changes in components of working capital, which we define for the purposes of this cash flow discussion as accounts receivable, net—Westlake, accounts receivable, net—third parties, inventories, prepaid expenses and other current assets less accounts payable—Westlake, accounts payable—third parties and accrued liabilities, provided cash of $35.0 million in the first six months of 2021 as compared to $2.1 million of cash used in the first six months of 2020, resulting in an overall favorable change of $37.1 million. The favorable change in working capital was mainly attributable to a favorable change in Westlake, net accounts receivable due to the receipt of the buyer deficiency fee recognized in 2020 related to the force majeure events partially offset by unfavorable changes in accounts receivable, net—third parties due to higher sales prices in the six months ended June 30, 2021.

21

Investing Activities

Net cash used for investing activities during the first six months of 2021 was $126.2 million as compared to net cash used for investing activities of $29.6 million in the first six months of 2020, mainly due to increased net cash used under the Investment Management Agreement in the first six months of 2021, as compared to the prior-year period. Capital expenditures during the first six months of 2021 and 2020 were primarily related to projects to improve production capacity or reduce costs, maintenance and safety and environmental projects at our facilities.

Financing Activities

Net cash used for financing activities during the first six months of 2021 was $160.4 million as compared to net cash used by financing activities of $190.4 million in the first six months of 2020. The outflows during the first six months of 2021 were related to the distribution of $127.3 million to Westlake and of $33.2 million to other unitholders by the Partnership. The cash outflows during the first six months of 2020 were related to the distribution of $157.2 million to Westlake and of $33.2 million to other unitholders by the Partnership.

LIQUIDITY AND CAPITAL RESOURCES

Liquidity and Financing Arrangements

Pursuant to the terms of the ATM Agreement, entered in October 2018 and amended in February 2020, among the Partnership and various investment banks, the Partnership may offer and sell the Partnership's common units from time to time to or through the Managers, as the Partnership's sales agents or as principals, having an aggregate offering amount of up to $50.0 million (the "ATM Program"). The Partnership intends to use the net proceeds of sales of the common units, if any, for general partnership purposes, including the funding of potential drop-downs and other acquisitions. No common units had been issued under the ATM Program as of June 30, 2021.

Based on the terms of our cash distribution policy, we expect that we will distribute to our partners most of the excess cash generated by our operations. To the extent we do not generate sufficient cash flow to fund capital expenditures, we expect to fund them primarily from external sources, including borrowing directly from Westlake, as well as future issuances of equity and debt interests.

The Partnership maintains separate bank accounts, but Westlake continues to provide treasury services on our behalf under the Services and Secondment Agreement. Our sources of liquidity include cash generated from operations, the OpCo Revolver, the MLP Revolver and, if necessary and possible under then current market conditions, the issuance of additional equity interests or debt. We believe that cash generated from these sources will be sufficient to meet our short-term working capital requirements and long-term capital expenditure requirements and to make quarterly cash distributions. Westlake may also provide other direct and indirect financing to us from time to time, although it is not required to do so.

In order to fund non-annual turnaround expenditures, we cause OpCo to reserve an amount for turnaround costs during each twelve-month period designed to cover future turnaround activities. Each of OpCo's ethylene production facilities requires turnaround maintenance approximately every five years. By reserving additional cash annually, we intend to reduce the variability in OpCo's cash flow. Westlake's purchase price for ethylene purchased under the Ethylene Sales Agreement includes a component (adjusted annually) designed to cover, over the long term, substantially all of OpCo's turnaround expenditures.

Westlake's credit facility and various indentures do not prevent OpCo from making distributions to us.

On August 2, 2021, the board of directors of Westlake Chemical Partners GP LLC, our general partner, approved a quarterly distribution of $0.4714 per unit payable on August 26, 2021 to unitholders of record as of August 12, 2021, which equates to a total amount of approximately $16.6 million per quarter, or approximately $66.4 million per year in aggregate, based on the number of common units outstanding on June 30, 2021. We do not have a legal or contractual obligation to pay distributions on a quarterly basis or any other basis at our minimum quarterly distribution rate or any other rate.

Capital Expenditures

Westlake has historically funded expansion capital expenditures related to Lake Charles Olefins and Calvert City Olefins. Total capital expenditures for the six months ended June 30, 2021 and 2020 were $27.3 million and $20.6 million, respectively. No funding was required by OpCo to fund capital expenditures during the six months ended June 30, 2021 and 2020. We expect that Westlake will loan additional cash to OpCo to fund its expansion capital expenditures in the future, but Westlake is under no obligation to do so.

22

Cash and Cash Equivalents

As of June 30, 2021, our cash and cash equivalents totaled $17.7 million. In addition, we have cash invested under the Investment Management Agreement (as described below) and a revolving credit facility with Westlake available to supplement cash if needed, as described under "Indebtedness" below.

In August 2017, the Partnership, OpCo and Westlake executed the Investment Management Agreement that authorized Westlake to invest the Partnership's and OpCo's excess cash with Westlake for a term of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. The Partnership had $222.2 million of cash invested under the Investment Management Agreement at June 30, 2021.

Indebtedness

OpCo Revolver

In connection with the IPO, OpCo entered into a $600.0 million revolving credit facility with Westlake, as amended in August and December 2017 and March 2020 (the "OpCo Revolver") that may be used to fund growth projects and working capital needs. The OpCo Revolver is scheduled to mature on September 25, 2023. As of June 30, 2021, outstanding borrowings under the OpCo Revolver totaled $22.6 million and bore interest at the LIBOR rate plus 2.0%, which is accrued in arrears quarterly.

MLP Revolver

In 2015, we entered into a senior, unsecured revolving credit agreement with an affiliate of Westlake (the "MLP Revolver"). The MLP Revolver has a borrowing capacity of $600.0 million and is scheduled to mature in 2023. On March 29, 2019, the Partnership borrowed $123.5 million under the MLP Revolver to partially fund the purchase of an additional 4.5% interest in OpCo. On March 19, 2020, the Partnership entered into an amendment to the MLP Revolver, to extend the maturity date to March 19, 2023 and add a phase-out provision for LIBOR, which is to be replaced by an alternate benchmark rate. Borrowings under the MLP Revolver bear interest at a variable rate of either (a) LIBOR plus 2.0% or, if LIBOR is no longer available, (b) Alternate Base Rate plus 1.0%. The MLP Revolver provides that we may pay all or a portion of the interest on any borrowings in kind, in which case any such amounts would be added to the principal amount of the loan. The MLP Revolver requires that we maintain a consolidated leverage ratio of either (1) during any one-year period following certain types of acquisitions (including acquisitions of additional interests in OpCo), 5.50:1.0 or less, or (2) during any other period, 4.50:1.00 or less. The MLP Revolver also contains certain other customary covenants. The repayment of borrowings under the MLP Revolver is subject to acceleration upon the occurrence of an event of default. As of June 30, 2021, outstanding borrowings under the MLP Revolver totaled $377.1 million and bore interest at the LIBOR rate plus 2.0%, which is accrued in arrears quarterly. We intend to use the MLP Revolver to purchase additional limited partnership interests in OpCo in the future, in the event OpCo desires to sell such additional interests to us, for other acquisitions and for general corporate purposes.

Off-Balance Sheet Arrangements

None.

23

FORWARD-LOOKING STATEMENTS

Certain of the statements contained in this report are forward-looking statements. All statements, other than statements of historical facts, included in this report that address activities, events or developments that we expect, project, believe or anticipate will or may occur in the future are forward-looking statements. Forward-looking statements can be identified by the use of words such as "believes," "intends," "may," "should," "could," "anticipates," "expects," "will" or comparable terminology, or by discussions of strategies or trends. Although we believe that the expectations reflected in such forward-looking statements are reasonable, we cannot give any assurances that these expectations will prove to be correct. Forward-looking statements relate to matters such as:

•the amount of ethane that we are able to process, which could be adversely affected by, among other things, operating difficulties;

•the volume of ethylene that we are able to sell;

•the price at which we are able to sell ethylene;

•industry market outlook, including prices and margins in third-party ethylene and co-products sales;

•widespread outbreak of an illness or any other communicable disease, or any other public health crisis, including the COVID-19 pandemic and efforts to contain its transmission;

•our plans and Westlake's plans to respond to the challenges presented by the COVID-19 epidemic, as well as the timing and deferral of the planned turnaround at OpCo's Petro 2 ethylene unit;

•the parties to whom we will sell ethylene and on what basis;

•volumes of ethylene that Westlake may purchase, in addition to the minimum commitment under the Ethylene Sales Agreement;

•timing, funding and results of capital expenditures;

•our intended quarterly distributions and the manner of making such distributions;

•our ability to meet our liquidity needs;

•timing of and amount of capital expenditures;

•the Partnership's At-the-Market program and the use of any net proceeds from any sales under that program;

•potential loans from Westlake to OpCo to fund OpCo's expansion capital expenditures in the future;

•expected mitigation of exposure to commodity price fluctuations;

•turnaround activities and the variability of OpCo's cash flow;

•receipt of any buyer deficiency fee and Shortfall under the Ethylene Sales Agreement;

•compliance with present and future environmental regulations and costs associated with environmentally related penalties, capital expenditures, remedial actions and proceedings, including any new laws, regulations or treaties that may come into force to limit or control carbon dioxide and other greenhouse gas emissions or to address other issues of climate change;

•our ability to receive indemnification from Westlake for environmental and other losses; and

•effects of pending legal proceedings.

24

We have based these statements on assumptions and analysis in light of our experience and perception of historical trends, current conditions, expected future developments and other factors we believe were appropriate in the circumstances when the statements were made. Forward-looking statements by their nature involve substantial risks and uncertainties that could significantly impact expected results, and actual future results could differ materially from those described in such statements. These statements are subject to a number of assumptions, risks and uncertainties, including those described under "Risk Factors" in the 2020 Form 10-K and the following:

•general economic and business conditions;

•the cyclical nature of the chemical industry;

•the availability, cost and volatility of raw materials and energy;

•low crude oil prices reducing the cost advantage of ethane-based ethylene producers;

•uncertainties associated with the United States and worldwide economies, including those due to political tensions and unrest in the Middle East and elsewhere;

•uncertainties associated with pandemic infectious diseases, particularly COVID-19;

•current and potential governmental regulatory actions in the United States and regulatory actions and political unrest in other countries, including environmental regulations;

•industry production capacity and operating rates;

•the supply/demand balance for our products;

•competitive products and pricing pressures;

•instability in the credit and financial markets;

•access to capital markets;

•terrorist acts;

•operating interruptions (including leaks, explosions, fires, weather-related incidents, mechanical failure, unscheduled downtime, labor difficulties, transportation interruptions, spills and releases and other environmental risks);

•changes in laws or regulations;

•technological developments;

•our ability to integrate acquired businesses;

•foreign currency exchange risks;

•our ability to implement our business strategies; and

•creditworthiness of our customers.

Many of these factors are beyond our ability to control or predict. Any of the factors, or a combination of these factors, could materially affect our future results of operations and the ultimate accuracy of the forward-looking statements. These forward-looking statements are not guarantees of our future performance, and our actual results and future developments may differ materially from those projected in the forward-looking statements. Management cautions against putting undue reliance on forward-looking statements or projecting any future results based on such statements or present or prior earnings levels. Every forward-looking statement speaks only as of the date of the particular statement, and we undertake no obligation to publicly update or revise any forward-looking statements.

25

Item 3. Quantitative and Qualitative Disclosures about Market Risk

Commodity Price Risk

A substantial portion of the Partnership's products and raw materials are commodities whose prices fluctuate as market supply and demand fundamentals change. However, our direct exposure to commodity price risk is limited to approximately 5.0% of our total ethylene production, which is the portion sold to third parties. We believe we have substantially mitigated our indirect exposure to commodity price fluctuation during the term of the Ethylene Sales Agreement through the minimum commitment and the cost-plus based pricing. Additionally, we may use derivative instruments to reduce price volatility risk on feedstocks and ethylene associated with the production and sales to third parties. We did not have any open derivative position at June 30, 2021.

Interest Rate Risk

We are exposed to interest rate risk with respect to our outstanding debt, all of which is variable rate debt. At June 30, 2021, we had total variable rate debt of $399.7 million outstanding, all of which was owed to wholly-owned subsidiaries of Westlake, and currently accrues interest at a variable rate of LIBOR plus 200 basis points. On March 19, 2020, the Partnership entered into an amendment to the MLP Revolver to extend the maturity date to March 19, 2023 and add a phase-out provision for LIBOR, which is to be replaced by an alternate benchmark rate. The amended credit agreement bears interest at a variable rate of either (a) LIBOR plus 2.0% or, if LIBOR is no longer available, (b) Alternate Base Rate plus 1.0%. The weighted average variable interest rate of our debt as of June 30, 2021 was 2.2%. We will continue to be subject to interest rate risk with respect to our variable rate debt as well as the risk of higher interest cost if and when this debt is refinanced. A hypothetical increase in our average interest rate on variable rate debt by 100 basis points would increase our annual interest expense by approximately $4.0 million, based on the June 30, 2021 debt balance.

LIBOR is used as a reference rate for all of our outstanding variable rate debt as of June 30, 2021. The phase-out of LIBOR is set to commence at the end of 2021 and conclude by June 30, 2023. We are currently reviewing how LIBOR phase-out will affect us, but we do not expect the impact to be material.

Item 4. Controls and Procedures

We carried out an evaluation, under the supervision and with the participation of our management, including our President and Chief Executive Officer and our Executive Vice President and Chief Financial Officer, of the effectiveness of our disclosure controls and procedures pursuant to Rules 13a-15 or 15d-15 under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), as of the end of the period covered by this report. Based upon that evaluation, our President and Chief Executive Officer and our Executive Vice President and Chief Financial Officer concluded that our disclosure controls and procedures are effective with respect to (i) the accumulation and communication to our management, including our Chief Executive Officer and our Chief Financial Officer, of information required to be disclosed by us in the reports that we submit under the Exchange Act, and (ii) the recording, processing, summarizing and reporting of such information within the time periods specified in the SEC's rules and forms.

There were no changes in our internal control over financial reporting that occurred during the three months ended June 30, 2021 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II. OTHER INFORMATION

Item 1. Legal Proceedings

The 2020 Form 10-K, filed on March 2, 2021, contained a description of various legal proceedings in which we are involved, including environmental proceedings. See below and Note 12 to the unaudited consolidated financial statements within this Quarterly Report on Form 10-Q for a discussion on legal proceedings, which information is incorporated by reference herein.

Under the Omnibus Agreement, Westlake Chemical Corporation ("Westlake") has agreed to indemnify the Partnership for certain environmental and other liabilities relating to OpCo's processing facilities and related assets.

26

Potential Flare Modifications. For several years, the Environmental Protection Agency ("EPA") has been conducting an enforcement initiative against petroleum refineries and petrochemical plants with respect to emissions from flares. On April 21, 2014, Westlake received a Clean Air Act Section 114 Information Request from the EPA, which sought information regarding flares at the Calvert City and Lake Charles facilities. The EPA has informed Westlake that the information provided leads the EPA to believe that some of the flares are out of compliance with applicable standards. The EPA has indicated that it is seeking a consent decree that would obligate Westlake to take corrective actions relating to the alleged noncompliance. The Partnership believes the resolution of these matters may require the payment of a monetary sanction in excess of $300,000. As discussed above, Westlake is expected to fully indemnify us for such costs.

In addition to the matters described above, the Partnership is involved in various legal proceedings incidental to the conduct of its business. The Partnership does not believe that any of these legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows.

Item 1A. Risk Factors

For a discussion of risk factors, please read Item 1A, "Risk Factors" in the 2020 Form 10-K. There have been no material changes from those risk factors.

Item 6. Exhibits

Exhibit No.	Exhibit
31.1†	Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Executive Officer)
31.2†	Rule 13a – 14(a) / 15d – 14(a) Certification (Principal Financial Officer)
32.1#	Section 1350 Certification (Principal Executive Officer and Principal Financial Officer)
101.INS†	XBRL Instance Document–The instance document does not appear in the interactive data file because its XBRL tags are embedded within the Inline XBRL document.
101.SCH†	XBRL Taxonomy Extension Schema Document
101.CAL†	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF†	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB†	XBRL Taxonomy Extension Label Linkbase Document
101.PRE†	XBRL Taxonomy Extension Presentation Linkbase Document
104	Cover Page Interactive Data File - The cover page interactive data file does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document.

_____________

†    Filed herewith.

#    Furnished herewith.

27

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

		WESTLAKE CHEMICAL PARTNERS LP
Date:	August 4, 2021	By:	/S/    ALBERT CHAO
			Albert Chao
			President, Chief Executive Officer and Director of Westlake Chemical Partners GP LLC (Principal Executive Officer)
Date:	August 4, 2021	By:	/S/    M. STEVEN BENDER
			M. Steven Bender
			Executive Vice President, Chief Financial Officer and Director of Westlake Chemical Partners GP LLC (Principal Financial Officer)

28

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Albert Chao, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Westlake Chemical Partners LP;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:	August 4, 2021	/S/    ALBERT CHAO
		Albert Chao
		President, Chief Executive Officer and Director of Westlake Chemical Partners GP LLC (Principal Executive Officer)

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, M. Steven Bender, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Westlake Chemical Partners LP;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5. The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

a) all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b) any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

Date:	August 4, 2021	/S/ M. STEVEN BENDER
		M. Steven Bender
		Executive Vice President, Chief Financial Officer and Director of Westlake Chemical Partners GP LLC (Principal Financial Officer)

EX-32.1

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Westlake Chemical Partners LP (the "Partnership") on Form 10-Q for the fiscal quarter ended June 30, 2021 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Albert Chao, President, Chief Executive Officer and Director of the Partnership, and I, M. Steven Bender, Senior Vice President, Chief Financial Officer and Director of the Partnership, certify, to the best of our knowledge, pursuant to 18 U.S.C. §1350, as adopted pursuant to §906 of the Sarbanes-Oxley Act of 2002, that:

(1)The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2)The information contained in the Report fairly presents, in all material aspects, the financial condition and results of operations of the Partnership.

Date:	August 4, 2021	/S/    ALBERT CHAO
		Albert Chao
		President, Chief Executive Officer and Director of Westlake Chemical Partners GP LLC (Principal Executive Officer)
Date:	August 4, 2021	/S/    M. STEVEN BENDER
		M. Steven Bender
		Executive Vice President, Chief Financial Officer and Director of Westlake Chemical Partners GP LLC (Principal Financial Officer)

XML

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	Jun. 30, 2021	Jul. 28, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-36567
Entity Registrant Name	Westlake Chemical Partners LP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	32-0436529
Entity Address, Address Line One	2801 Post Oak Boulevard
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056
City Area Code	713
Local Phone Number	585-2900
Title of 12(b) Security	Common units representing limited partnership interests
Trading Symbol	WLKP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Units, Units Outstanding		35,204,561
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Document Fiscal Year Focus	2021
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Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 17,665	$ 17,154
Receivable under the Investment Management Agreement—Westlake Chemical Corporation ("Westlake")	222,249	123,228
Accounts receivable, net—Westlake	66,948
Accounts receivable, net—third parties	24,962	11,029
Inventories	4,929	3,474
Prepaid expenses and other current assets	61	392
Total current assets	336,814	263,305
Property, plant and equipment, net	1,030,016	1,050,677
Goodwill	5,814	5,814
Deferred charges and other assets, net	29,111	36,692
Total assets	1,401,755	1,356,488
Current liabilities
Accounts payable—Westlake	20,134	7,855
Accounts payable—third parties	12,435	13,131
Accrued and other liabilities	16,084	18,768
Total current liabilities	48,653	39,754
Long-term debt payable to Westlake	399,674	399,674
Deferred income taxes	1,634	1,542
Other liabilities	36	381
Total liabilities	449,997	441,351
Commitments and contingencies (Note 12)
EQUITY
Total Westlake Chemical Partners LP partners' capital	284,607	277,399
Noncontrolling interest in Westlake Chemical OpCo LP ("OpCo")	667,151	637,738
Total equity	951,758	915,137
Total liabilities and equity	1,401,755	1,356,488
Limited Partner | Common units | Publicly and Privately Held
EQUITY
Limited Partners' Capital Account	476,076	471,701
Total equity	476,076	471,701
Limited Partner | Common units | Westlake
EQUITY
Limited Partners' Capital Account	51,103	48,270
Total equity	51,103	48,270
General Partner | Westlake
EQUITY
General partner—Westlake	(242,572)	(242,572)
Total equity	$ (242,572)	$ (242,572)

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Consolidated Balance Sheets (Parenthetical) - Common units - shares	Jun. 30, 2021	Dec. 31, 2020
Publicly and Privately Held
Units issued	21,082,331	21,076,673
Westlake
Units issued	14,122,230	14,122,230

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Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net sales—Westlake	$ 240,956	$ 227,431	$ 460,759	$ 442,259
Total net sales	322,229	238,500	590,436	489,049
Cost of sales	191,200	148,470	371,708	295,471
Gross profit	131,029	90,030	218,728	193,578
Selling, general and administrative expenses	8,269	6,139	16,942	12,335
Income from operations	122,760	83,891	201,786	181,243
Other income (expense)
Interest expense—Westlake	(2,224)	(3,431)	(4,460)	(7,381)
Other income, net	21	123	28	708
Income before income taxes	120,557	80,583	197,354	174,570
Income tax provision	263	206	438	423
Net income	120,294	80,377	196,916	174,147
Less: Net income attributable to noncontrolling interest in OpCo	95,195	65,517	156,671	141,540
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 25,099	$ 14,860	$ 40,245	$ 32,607
Net income per limited partner unit attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in units)	35,201,887	35,194,545	35,200,403	35,194,545
Common units
Other income (expense)
Net income attributable to Westlake Chemical Partners LP and limited partners' interest in net income	$ 25,099	$ 14,860	$ 40,245	$ 32,607
Net income per limited partner unit attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Common units (in usd per share)	$ 0.71	$ 0.43	$ 1.14	$ 0.93
Weighted average limited partner units outstanding (basic and diluted) (in units)	35,201,887	35,194,545	35,200,403	35,194,545
Common units | Publicly and Privately Held
Net income per limited partner unit attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in units)	21,079,657	21,072,315	21,078,173	21,072,315
Common units | Westlake
Net income per limited partner unit attributable to Westlake Chemical Partners LP per limited partner unit (basic and diluted)
Weighted average limited partner units outstanding (basic and diluted) (in units)	14,122,230	14,122,230	14,122,230	14,122,230
Net co-product, ethylene and other sales—third parties
Total net sales	$ 81,273	$ 11,069	$ 129,677	$ 46,790

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Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Noncontrolling Interest in OpCo	Westlake General Partner	Common units Publicly and Privately Held Limited Partner	Common units Westlake Limited Partner
Total equity at Dec. 31, 2019	$ 952,135	$ 674,621	$ (242,572)	$ 471,736	$ 48,350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	93,770	76,023		10,626	7,121
Quarterly distribution to unitholders	(16,591)			(9,934)	(6,657)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake	(79,223)	(79,223)
Total equity at Mar. 31, 2020	950,091	671,421	(242,572)	472,428	48,814
Total equity at Dec. 31, 2019	952,135	674,621	(242,572)	471,736	48,350
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	174,147
Total equity at Jun. 30, 2020	935,853	658,913	(242,572)	471,392	48,120
Total equity at Mar. 31, 2020	950,091	671,421	(242,572)	472,428	48,814
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	80,377	65,517		8,897	5,963
Quarterly distribution to unitholders	(16,590)			(9,933)	(6,657)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake	(78,025)	(78,025)
Total equity at Jun. 30, 2020	935,853	658,913	(242,572)	471,392	48,120
Total equity at Dec. 31, 2020	915,137	637,738	(242,572)	471,701	48,270
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	76,622	61,476		9,069	6,077
Quarterly distribution to unitholders	(16,593)			(9,936)	(6,657)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake	(62,058)	(62,058)
Total equity at Mar. 31, 2021	913,108	637,156	(242,572)	470,834	47,690
Total equity at Dec. 31, 2020	915,137	637,738	(242,572)	471,701	48,270
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	196,916
Total equity at Jun. 30, 2021	951,758	667,151	(242,572)	476,076	51,103
Total equity at Mar. 31, 2021	913,108	637,156	(242,572)	470,834	47,690
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	120,294	95,195		15,029	10,070
Stock Issued During Period, Value, Other	149			149
Quarterly distribution to unitholders	(16,593)			(9,936)	(6,657)
Quarterly distribution to noncontrolling interest retained in OpCo by Westlake	(65,200)	(65,200)
Total equity at Jun. 30, 2021	$ 951,758	$ 667,151	$ (242,572)	$ 476,076	$ 51,103

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Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net income	$ 196,916	$ 174,147
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	56,244	51,844
Loss from disposition of property, plant and equipment	1,391	446
Other gains, net	759	(310)
Changes in operating assets and liabilities
Accounts receivable—third parties	(14,600)	3,235
Net accounts receivable—Westlake	53,191	(8,890)
Inventories	(1,455)	955
Prepaid expenses and other current assets	331	405
Accounts payable	653	1,207
Accrued and other liabilities	(3,140)	998
Other, net	(3,172)	(318)
Cash flows from investing activities	287,118	223,719
Cash flows from investing activities
Additions to property, plant and equipment	(27,289)	(20,595)
Maturities of investments with Westlake under the Investment Management Agreement	83,000	181,000
Investments with Westlake under the Investment Management Agreement	(182,000)	(190,000)
Other	126	0
Net cash used for investing activities	(126,163)	(29,595)
Cash flows from financing activities
Quarterly distributions to noncontrolling interest retained in OpCo by Westlake	(127,258)	(157,248)
Quarterly distributions to unitholders	(33,186)	(33,181)
Net cash used for financing activities	(160,444)	(190,429)
Net increase in cash and cash equivalents	511	3,695
Cash and cash equivalents at beginning of period	17,154	19,923
Cash and cash equivalents at end of period	$ 17,665	$ 23,618

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Description of Business and Basis of Presentation

6 Months Ended

Jun. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business and Basis of Presentation

Description of Business and Basis of Presentation

Description of Business

Westlake Chemical Partners LP (the "Partnership") is a Delaware limited partnership formed in March 2014 to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests.

In connection with the IPO, the Partnership acquired a 10.6% limited partner interest in Westlake Chemical OpCo LP ("OpCo") and a 100% interest in Westlake Chemical OpCo GP LLC ("OpCo GP"), which is the general partner of OpCo. OpCo owns three ethylene production facilities and one common carrier ethylene pipeline (collectively, the "Contributed Assets"). Since the IPO, the Partnership has periodically purchased additional limited partner interest in OpCo. Most recently, on March 29, 2019, the Partnership purchased an additional 4.5% newly-issued limited partner interest in OpCo for approximately $201,445, resulting in an aggregate 22.8% limited partner interest in OpCo, effective January 1, 2019. The remaining 77.2% limited partner interest in OpCo is owned by Westlake Chemical Corporation.

Basis of Presentation

The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), filed with the SEC on March 2, 2021. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2020.

References to "Westlake" refer collectively to Westlake Chemical Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

The Partnership holds a 22.8% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 77.2% limited partner interest in OpCo is owned directly by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. Westlake's retained interest of 77.2% is recorded as noncontrolling interest in the Partnership's consolidated financial statements.

In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of June 30, 2021, its results of operations for the three and six months ended June 30, 2021 and 2020 and the changes in its cash position for the six months ended June 30, 2021 and 2020.

Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2021 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates.

The COVID pandemic resulted in widespread adverse impacts on the global economy in 2020. The Partnership has not experienced significant disruptions to its business operations in 2020 or during the six months ended June 30, 2021 and does not expect significant disruptions to its business operations resulting from COVID-19. However, the impact that COVID-19 will have on the Partnership's financial condition, results of operations and cash flows cannot be estimated with certainty at this time as it will depend on future developments, including, among others, the timing and logistics with respect to the distribution of vaccines globally and the efficacy of the available vaccines (including with respect to the more recent variants of COVID-19) and other treatments, the ultimate duration of the pandemic, geographic spread and severity of the virus, the consequences of governmental and other measures designed to prevent the spread of the virus, the impact on the operation of OpCo's facilities, Westlake, customers, suppliers and other third parties and the timing and extent to which normal economic and operating conditions resume.

Recent Accounting Pronouncements

Reference Rate Reform (ASU No. 2020-04)

In March 2020, the FASB issued an accounting standards update to provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met.

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Accounts Receivable - Third Parties

6 Months Ended

Jun. 30, 2021

Accounts Receivable, after Allowance for Credit Loss [Abstract]

Accounts Receivable - Third Parties

Accounts Receivable—Third Parties

Accounts receivable—third parties consist of the following:

	June 30, 2021		December 31, 2020
Trade customers	$	25,908	$	11,344
Allowance for credit losses	(982)		(315)
	24,926		11,029
Other receivables	36		—
Accounts receivable, net—third parties	$	24,962	$	11,029

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Inventories

6 Months Ended

Jun. 30, 2021

Inventory Disclosure [Abstract]

Inventories

Inventories

Inventories consist of the following:

	June 30, 2021		December 31, 2020
Finished products	$	4,566	$	3,157
Feedstock, additives and chemicals	363		317
Inventories	$	4,929	$	3,474

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Property, Plant and Equipment	6 Months Ended
	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Depreciation expense on property, plant and equipment of $22,983 and $22,714 is included in cost of sales in the consolidated statements of operations for the three months ended June 30, 2021 and 2020, respectively. Depreciation expense on property, plant and equipment of $45,785 and $45,467 is included in cost of sales in the consolidated statements of operations for the six months ended June 30, 2021 and 2020, respectively.

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Deferred Charges and Other Assets	6 Months Ended
	Jun. 30, 2021
Other Assets, Noncurrent [Abstract]
Deferred Charges and Other Assets	Deferred Charges and Other Assets Amortization expense on other assets of $5,719 and $3,099 is included in costs of sales in the consolidated statements of operations for the three months ended June 30, 2021 and 2020, respectively. Amortization expense on other assets of $10,459 and $6,377 is included in costs of sales in the consolidated statements of operations for the six months ended June 30, 2021 and 2020, respectively.

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Distributions and Net Income Per Limited Partner Unit

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Distributions and Net Income Per Limited Partner Unit

Distributions and Net Income Per Limited Partner Unit

On August 2, 2021, the board of directors of Westlake Chemical Partners GP LLC ("Westlake GP"), the Partnership's general partner, declared a quarterly cash distribution for the three months ended June 30, 2021 of $0.4714 per unit. This distribution is payable on August 26, 2021 to unitholders of record as of August 12, 2021.

Distributions are declared subsequent to quarter end; therefore, the table below represents total cash distributions declared from earnings of the related periods pertaining to such distributions.

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Net income attributable to the Partnership	$	25,099	$	14,860	$	40,245	$	32,607
Less:
Limited partners' distribution declared on common units	16,595		16,590		33,188		33,181
Net income in excess of distribution (distribution in excess of net income)	$	8,504	$	(1,730)	$	7,057	$	(574)

Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statements of changes in equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

	Three Months Ended June 30, 2021
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,595	$	—	$	16,595
Net income in excess of distribution	8,504		—		8,504
Net income	$	25,099	$	—	$	25,099
Weighted average units outstanding:
Basic and diluted	35,201,887				35,201,887
Net income per limited partner unit:
Basic and diluted	$	0.71

	Three Months Ended June 30, 2020
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,590	$	—	$	16,590
Distribution in excess of net income	(1,730)		—		(1,730)
Net income	$	14,860	$	—	$	14,860
Weighted average units outstanding:
Basic and diluted	35,194,545				35,194,545
Net income per limited partner unit:
Basic and diluted	$	0.43

	Six Months Ended June 30, 2021
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,188	$	—	$	33,188
Net income in excess of distribution	7,057		—		7,057
Net income	$	40,245	$	—	$	40,245
Weighted average units outstanding:
Basic and diluted	35,200,403				35,200,403
Net income per limited partner unit:
Basic and diluted	$	1.14

	Six Months Ended June 30, 2020
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,181	$	—	$	33,181
Distribution in excess of net income	(574)		—		(574)
Net income	$	32,607	$	—	$	32,607
Weighted average units outstanding:
Basic and diluted	35,194,545				35,194,545
Net income per limited partner unit:
Basic and diluted	$	0.93

The amended Partnership Agreement provides that the Partnership will distribute cash each quarter to all the unitholders, pro rata, until each unit has received a distribution of $1.2938. If cash distributions to the Partnership's unitholders exceed $1.2938 per common unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations:

	Marginal Percentage Interest in Distributions
Total Quarterly Distribution Per Unit	Unitholders		IDR Holders
Above $1.2938 up to $1.4063	85.0	%	15.0	%
Above $1.4063 up to $1.6875	75.0	%	25.0	%
Above $1.6875	50.0	%	50.0	%

The Partnership's distribution for the three months ended June 30, 2021 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights.

Distribution Per Common Unit

Distributions per common unit for the three and six months ended June 30, 2021 and 2020 were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Distributions per common unit	$	0.4714	$	0.4714	$	0.9428	$	0.9428

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Partners' Equity

6 Months Ended

Jun. 30, 2021

Equity [Abstract]

Partners' Equity

7. Partners' Equity

On October 4, 2018, the Partnership and Westlake Chemical Partners GP LLC, the general partner of the Partnership, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell the Partnership's common units, from time to time, up to an aggregate offering amount of $50,000. The Equity Distribution Agreement was amended on February 28, 2020 to reference a new shelf registration for utilization under this agreement. No common units were issued under this program as of June 30, 2021.

On March 29, 2019, the Partnership completed the issuance and sale of 2,940,818 common units at a price of $21.40 per unit through a private placement. TTWF LP, Westlake's principal stockholder and a related party, acquired 1,401,869 common units out of 2,940,818 common units issued in the private placement.

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Related Party Transactions

6 Months Ended

Jun. 30, 2021

Related Party Transactions [Abstract]

Related Party Transactions

8. Related Party Transactions

The Partnership and OpCo regularly enter into related party transactions with Westlake. See below for a description of transactions with related parties.

Sales to Related Parties

OpCo sells ethylene to Westlake under the Ethylene Sales Agreement. Additionally, the Partnership and OpCo from time to time provide other services or products for which it charges Westlake a fee.

Sales to related parties were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Net sales—Westlake	$	240,956	$	227,431	$	460,759	$	442,259

During June 2021, OpCo's Petro 1 facility experienced an outage, which resulted in a force majeure event under the Ethylene Sales Agreement. In addition, OpCo declared a force majeure in February 2021 due to the severe winter storm. As a result of these force majeure events, the Partnership updated its estimate of OpCo's 2021 anticipated production as of June 30, 2021. The buyer deficiency fee is measured based upon the lower of the actual production deficiency at period end or the estimated annual production deficiency based upon OpCo's annual anticipated production. Based upon this change in estimate of OpCo's 2021 anticipated production, the Partnership has recognized buyer deficiency fees and shortfall fees of $8,742 and $18,420 during the three and six months ended June 30, 2021, respectively. The buyer deficiency fees and shortfall fees are classified as a component of net sales.

During 2020, the Lake Charles Petro 1 and Petro 2 facilities were impacted by Hurricanes Laura and Delta, which resulted in force majeure events under the Ethylene Sales Agreement. As a result of the force majeure events, the Partnership recognized a buyer deficiency fee of $69,555 as a component of net sales in 2020. Payment for the buyer deficiency fee was received by the Partnership in January 2021.

Cost of Sales from Related Parties

Charges for goods and services purchased by the Partnership and OpCo from Westlake and included in cost of sales relate primarily to feedstock purchased under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement.

Charges from related parties in cost of sales were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Feedstock purchased from Westlake and included in cost of sales	$	100,979	$	69,324	$	183,095	$	128,962
Other charges from Westlake and included in cost of sales	27,466		23,898		59,308		47,998
Total	$	128,445	$	93,222	$	242,403	$	176,960

Services from Related Parties Included in Selling, General and Administrative Expenses

Charges for services purchased by the Partnership from Westlake and included in selling, general and administrative expenses primarily relate to services Westlake performs on behalf of the Partnership under the Omnibus Agreement, including the Partnership's finance, legal, information technology, human resources, communication, ethics and compliance and other administrative functions.

Charges from related parties included within selling, general and administrative expenses were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Services received from Westlake and included in selling, general and administrative expenses	$	7,000	$	5,698	$	14,912	$	10,813

Goods and Services from Related Parties Capitalized as Assets

Charges for goods and services purchased by the Partnership and OpCo from Westlake which were capitalized as assets relate primarily to the services of Westlake employees under the Services and Secondment Agreement.

Charges from related parties for goods and services capitalized as assets were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Goods and services purchased from Westlake and capitalized as assets	$	533	$	384	$	936	$	864

Receivable under the Investment Management Agreement

On August 1, 2017, the Partnership, OpCo and Westlake executed an investment management agreement (the "Investment Management Agreement") that authorized Westlake to invest the Partnership's and OpCo's excess cash with Westlake for a term of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. Accrued interest of $77 and $56 was included in the receivable under the Investment Management Agreement balance at June 30, 2021 and December 31, 2020, respectively. Total interest earned related to the Investment Management Agreement was $77 and $219 for the three months ended June 30, 2021 and 2020, respectively, and $145 and $807 for the six months ended June 30, 2021 and 2020, respectively.

The Partnership's receivable under the Investment Management Agreement was as follows:

	June 30, 2021		December 31, 2020
Receivable under the Investment Management Agreement	$	222,249	$	123,228

Accounts Receivable from Related Parties

The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake and the buyer deficiency fee and shortfall fee recognized under the Ethylene Sales Agreement, as discussed above under "Sales to Related Parties." The buyer deficiency fee and shortfall fee recognized in the six months ended June 30, 2021are scheduled to be received by the Partnership after the end of 2021.

The Partnership's accounts receivable from Westlake were as follows:

	June 30, 2021		December 31, 2020
Accounts receivable—Westlake	$	66,948	$	108,028

Accounts Payable to Related Parties

The Partnership's accounts payable to Westlake result primarily from feedstock purchases under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement and the Omnibus Agreement.

The related party accounts payable balances were as follows:

	June 30, 2021		December 31, 2020
Accounts payable—Westlake	$	20,134	$	7,855

Related Party Leases

OpCo is obligated to Westlake under various long-term and short-term noncancelable operating leases, primarily related to rail car leases and land. Operating lease rentals paid to Westlake for such leases were $608 and $726 for the three months ended June 30, 2021 and 2020, respectively, and $1,295 and $1,396 for the six months ended June 30, 2021 and 2020, respectively, and reflected in other charges from Westlake that are included in cost of sales.

OpCo has two site lease agreements with Westlake, each of which has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year.

Debt Payable to Related Parties

See Note 9 for a description of related party debt payable balances.

Interest on related party debt payable balances for the three months ended June 30, 2021 and 2020 was $2,224 and $3,431, respectively. Interest on related party debt payable is presented as interest expense—Westlake in the consolidated statements of operations. At June 30, 2021 and December 31, 2020, accrued interest on related party debt was $2,224 and $2,336, respectively, and is reflected as a component of accrued liabilities in the consolidated balance sheets.

Debt payable to related parties was as follows:

	June 30, 2021		December 31, 2020
Long-term debt payable to Westlake	$	399,674	$	399,674

Major Customer and Concentration of Credit Risk

During the three months ended June 30, 2021 and 2020, Westlake accounted for approximately 74.8% and 95.4%, respectively, of the Partnership's net sales. During the six months ended June 30, 2021 and 2020, Westlake accounted for approximately 78.0% and 90.4%, respectively, of the Partnership's net sales.

Other

See Note 7 above for an additional related party transaction.

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Long-term Debt Payable to Westlake

6 Months Ended

Jun. 30, 2021

Related Party Transactions [Abstract]

Long-term Debt Payable to Westlake

Long-term Debt Payable to Westlake

Long-term debt payable to Westlake consists of the following:

	June 30, 2021		December 31, 2020
OpCo Revolver (variable interest rate of London Interbank Offered Rate ("LIBOR") plus 2.0%, scheduled maturity of September 25, 2023)	$	22,619	$	22,619
MLP Revolver (variable interest rate of LIBOR plus 2.0%, scheduled maturity of March 19, 2023)	377,055		377,055
	$	399,674	$	399,674

The weighted average interest rate on all long-term debt was 2.2% at June 30, 2021 and December 31, 2020.

As of June 30, 2021, the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver.

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Fair Value Measurements

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

Fair Value Measurements

The Partnership reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). Under the accounting guidance for fair value measurements, inputs used to measure fair value are classified in one of three levels:

Level 1: Quoted market prices in active markets for identical assets or liabilities.

Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.

Level 3: Unobservable inputs that are not corroborated by market data.

The Partnership has financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt payable to Westlake, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Partnership's long-term debt at June 30, 2021 and December 31, 2020 are summarized in the table below. The Partnership's long-term debt includes the OpCo Revolver and the MLP Revolver at June 30, 2021. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate.

	June 30, 2021				December 31, 2020
	Carrying Value		Fair Value		Carrying Value		Fair Value
OpCo Revolver	$	22,619	$	22,924	$	22,619	$	23,301
MLP Revolver	377,055		379,868		377,055		383,284

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Supplemental Information

6 Months Ended

Jun. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Supplemental Information

Supplemental Information

Accrued and Other Liabilities

Accrued and other liabilities were $16,084 and $18,768 at June 30, 2021 and December 31, 2020, respectively. Accrued taxes, accrued maintenance expense and accrued capital expenditures, which are components of accrued liabilities, were $3,925, $3,025 and $2,823, respectively, at June 30, 2021 and $6,207, $3,905 and $2,286, respectively, at December 31, 2020. No other component of accrued and other liabilities was more than five percent of total current liabilities.

Non-cash Investing Activity

The non-cash investing activities related to accruals for capital expenditures were $669 and $182 for the six months ended June 30, 2021 and 2020, respectively.

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Commitments and Contingencies

6 Months Ended

Jun. 30, 2021

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments and Contingencies

The Partnership is subject to environmental laws and regulations that can impose civil and criminal sanctions and that may require the Partnership to mitigate the effects of contamination caused by the release or disposal of hazardous substances into the environment. These laws include the federal Clean Air Act, the federal Water Pollution Control Act, the Resource Conservation and Recovery Act ("RCRA"), the Comprehensive Environmental Response, Compensation, and Liability Act ("CERCLA"), the Toxic Substances Control Act and various other federal, state and local laws and regulations. Under CERCLA, an owner or operator of property may be held strictly liable for remediating contamination without regard to whether that person caused the contamination, and without regard to whether the practices that resulted in the contamination were legal at the time they occurred. Because the Partnership's production sites have a history of industrial use, it is impossible to predict precisely what effect these legal requirements will have on the Partnership. Westlake will indemnify the Partnership for liabilities that occurred or existed prior to August 4, 2014.

The Partnership is involved in various legal proceedings incidental to the conduct of its business. The Partnership does not believe that any of these legal proceedings will have a material adverse effect on its financial condition, results of operations or cash flows.

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Description of Business and Basis of Presentation (Policies)

6 Months Ended

Jun. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Basis of Presentation

Basis of Presentation

The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2020 (the "2020 Form 10-K"), filed with the SEC on March 2, 2021. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2020.

References to "Westlake" refer collectively to Westlake Chemical Corporation and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

The Partnership holds a 22.8% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 77.2% limited partner interest in OpCo is owned directly by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. Westlake's retained interest of 77.2% is recorded as noncontrolling interest in the Partnership's consolidated financial statements.

In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of June 30, 2021, its results of operations for the three and six months ended June 30, 2021 and 2020 and the changes in its cash position for the six months ended June 30, 2021 and 2020.

Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2021 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates.

The COVID pandemic resulted in widespread adverse impacts on the global economy in 2020. The Partnership has not experienced significant disruptions to its business operations in 2020 or during the six months ended June 30, 2021 and does not expect significant disruptions to its business operations resulting from COVID-19. However, the impact that COVID-19 will have on the Partnership's financial condition, results of operations and cash flows cannot be estimated with certainty at this time as it will depend on future developments, including, among others, the timing and logistics with respect to the distribution of vaccines globally and the efficacy of the available vaccines (including with respect to the more recent variants of COVID-19) and other treatments, the ultimate duration of the pandemic, geographic spread and severity of the virus, the consequences of governmental and other measures designed to prevent the spread of the virus, the impact on the operation of OpCo's facilities, Westlake, customers, suppliers and other third parties and the timing and extent to which normal economic and operating conditions resume.

Recent Accounting Pronouncements

Recent Accounting Pronouncements

Reference Rate Reform (ASU No. 2020-04)

In March 2020, the FASB issued an accounting standards update to provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria are met. The amendments in this update are effective for all entities as of March 12, 2020 through December 31, 2022 and are not expected to have a material impact on the Partnership's consolidated financial position, results of operations and cash flows.

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Accounts Receivable - Third Parties (Tables)

6 Months Ended

Jun. 30, 2021

Accounts Receivable, after Allowance for Credit Loss [Abstract]

Schedule Of Accounts Receivable - Third Parties

Accounts receivable—third parties consist of the following:

	June 30, 2021		December 31, 2020
Trade customers	$	25,908	$	11,344
Allowance for credit losses	(982)		(315)
	24,926		11,029
Other receivables	36		—
Accounts receivable, net—third parties	$	24,962	$	11,029

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Inventories (Tables)

6 Months Ended

Jun. 30, 2021

Inventory Disclosure [Abstract]

Schedule Of Inventory

Inventories consist of the following:

	June 30, 2021		December 31, 2020
Finished products	$	4,566	$	3,157
Feedstock, additives and chemicals	363		317
Inventories	$	4,929	$	3,474

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Distributions and Net Income Per Limited Partner Unit (Tables)

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Schedule of Incentive Distributions Made to Managing Members or General Partners by Distribution

Distributions are declared subsequent to quarter end; therefore, the table below represents total cash distributions declared from earnings of the related periods pertaining to such distributions.

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Net income attributable to the Partnership	$	25,099	$	14,860	$	40,245	$	32,607
Less:
Limited partners' distribution declared on common units	16,595		16,590		33,188		33,181
Net income in excess of distribution (distribution in excess of net income)	$	8,504	$	(1,730)	$	7,057	$	(574)

Schedule of Earnings Per Share, Basic and Diluted

Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statements of changes in equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

	Three Months Ended June 30, 2021
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,595	$	—	$	16,595
Net income in excess of distribution	8,504		—		8,504
Net income	$	25,099	$	—	$	25,099
Weighted average units outstanding:
Basic and diluted	35,201,887				35,201,887
Net income per limited partner unit:
Basic and diluted	$	0.71

	Three Months Ended June 30, 2020
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	16,590	$	—	$	16,590
Distribution in excess of net income	(1,730)		—		(1,730)
Net income	$	14,860	$	—	$	14,860
Weighted average units outstanding:
Basic and diluted	35,194,545				35,194,545
Net income per limited partner unit:
Basic and diluted	$	0.43

	Six Months Ended June 30, 2021
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,188	$	—	$	33,188
Net income in excess of distribution	7,057		—		7,057
Net income	$	40,245	$	—	$	40,245
Weighted average units outstanding:
Basic and diluted	35,200,403				35,200,403
Net income per limited partner unit:
Basic and diluted	$	1.14

	Six Months Ended June 30, 2020
	Limited Partners' Common Units		Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution	$	33,181	$	—	$	33,181
Distribution in excess of net income	(574)		—		(574)
Net income	$	32,607	$	—	$	32,607
Weighted average units outstanding:
Basic and diluted	35,194,545				35,194,545
Net income per limited partner unit:
Basic and diluted	$	0.93

Distributions Made to Limited Partner, by Distribution [Table Text Block]

If cash distributions to the Partnership's unitholders exceed $1.2938 per common unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations:

	Marginal Percentage Interest in Distributions
Total Quarterly Distribution Per Unit	Unitholders		IDR Holders
Above $1.2938 up to $1.4063	85.0	%	15.0	%
Above $1.4063 up to $1.6875	75.0	%	25.0	%
Above $1.6875	50.0	%	50.0	%

The Partnership's distribution for the three months ended June 30, 2021 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights.

Distribution Per Common Unit

Distributions per common unit for the three and six months ended June 30, 2021 and 2020 were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Distributions per common unit	$	0.4714	$	0.4714	$	0.9428	$	0.9428

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Related Party Transactions (Tables)

6 Months Ended

Jun. 30, 2021

Related Party Transactions [Abstract]

Schedule of Related Party Transactions

Sales to related parties were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Net sales—Westlake	$	240,956	$	227,431	$	460,759	$	442,259

Charges from related parties in cost of sales were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Feedstock purchased from Westlake and included in cost of sales	$	100,979	$	69,324	$	183,095	$	128,962
Other charges from Westlake and included in cost of sales	27,466		23,898		59,308		47,998
Total	$	128,445	$	93,222	$	242,403	$	176,960

Charges from related parties included within selling, general and administrative expenses were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Services received from Westlake and included in selling, general and administrative expenses	$	7,000	$	5,698	$	14,912	$	10,813

Charges from related parties for goods and services capitalized as assets were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Goods and services purchased from Westlake and capitalized as assets	$	533	$	384	$	936	$	864

The Partnership's receivable under the Investment Management Agreement was as follows:

	June 30, 2021		December 31, 2020
Receivable under the Investment Management Agreement	$	222,249	$	123,228

The Partnership's accounts receivable from Westlake were as follows:

	June 30, 2021		December 31, 2020
Accounts receivable—Westlake	$	66,948	$	108,028

The related party accounts payable balances were as follows:

	June 30, 2021		December 31, 2020
Accounts payable—Westlake	$	20,134	$	7,855

Debt payable to related parties was as follows:

	June 30, 2021		December 31, 2020
Long-term debt payable to Westlake	$	399,674	$	399,674

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Long-term Debt Payable to Westlake (Tables)

6 Months Ended

Jun. 30, 2021

Related Party Transactions [Abstract]

Related Party Transactions, Long-term Debt

Long-term debt payable to Westlake consists of the following:

	June 30, 2021		December 31, 2020
OpCo Revolver (variable interest rate of London Interbank Offered Rate ("LIBOR") plus 2.0%, scheduled maturity of September 25, 2023)	$	22,619	$	22,619
MLP Revolver (variable interest rate of LIBOR plus 2.0%, scheduled maturity of March 19, 2023)	377,055		377,055
	$	399,674	$	399,674

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Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Summary Of Carrying And Fair Values Of Long-Term Debt

These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and long-term debt payable to Westlake, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Partnership's long-term debt at June 30, 2021 and December 31, 2020 are summarized in the table below. The Partnership's long-term debt includes the OpCo Revolver and the MLP Revolver at June 30, 2021. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for long-term debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's long-term debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's long-term debt include the selection of an appropriate discount rate.

	June 30, 2021				December 31, 2020
	Carrying Value		Fair Value		Carrying Value		Fair Value
OpCo Revolver	$	22,619	$	22,924	$	22,619	$	23,301
MLP Revolver	377,055		379,868		377,055		383,284

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Description of Business and Basis of Presentation (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 29, 2019	Aug. 04, 2014
Limited Partner
Limited Partners' Capital Account [Line Items]
Number of units sold in public offering	2,940,818	12,937,500
Units sold in secondary offering price per unit (in dollars per share)	$ 21.40
Westlake Chemical OpCo GP LLC | Limited Liability Company
Limited Partners' Capital Account [Line Items]
Limited partner interest		100.00%
Westlake Chemical OpCo LP | Affiliated Entity
Limited Partners' Capital Account [Line Items]
Limited partner interest	22.80%	10.60%
Limited partner interest, additional ownership	4.50%
Amount paid to purchase additional limited partner interest	$ 201,445
Westlake Chemical OpCo LP | Westlake | Majority-Owned Subsidiary, Unconsolidated
Limited Partners' Capital Account [Line Items]
Limited partner interest	77.20%

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Accounts Receivable - Third Parties Accounts Receivable—Third Parties (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Trade customers	$ 25,908	$ 11,344
Allowance for credit losses	(982)	(315)
Trade Customer Receivable Net Current	24,926	11,029
Other receivables	36	0
Accounts receivable, net—third parties	$ 24,962	$ 11,029

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Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Finished products	$ 4,566	$ 3,157
Feedstock, additives and chemicals	363	317
Inventories	$ 4,929	$ 3,474

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Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense on property, plant and equipment	$ 22,983	$ 22,714	$ 45,785	$ 45,467

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Deferred Charges and Other Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Deferred Charges and Other Assets
Other Assets [Line Items]
Amortization expense	$ 5,719	$ 3,099	$ 10,459	$ 6,377

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Distributions and Net Income Per Limited Partner Unit (Distributions Declared) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Aug. 02, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Distribution Made to Limited Partner [Line Items]
Net income in excess of distribution (distribution in excess of net income)		$ 8,504	$ (1,730)	$ 7,057	$ (574)
Net income attributable to the Partnership		$ 25,099	$ 14,860	$ 40,245	$ 32,607
Weighted average limited partner units outstanding (basic and diluted) (in units)		35,201,887	35,194,545	35,200,403	35,194,545
Distributions declared		$ 16,595	$ 16,590	$ 33,188	$ 33,181
IDR Holders
Distribution Made to Limited Partner [Line Items]
Net income in excess of distribution (distribution in excess of net income)		0	0	0	0
Net income attributable to the Partnership		0	0	0	0
Distributions declared with respect to the incentive distribution rights		0	0	0	0
Common units
Distribution Made to Limited Partner [Line Items]
Net income in excess of distribution (distribution in excess of net income)		8,504	(1,730)	7,057	(574)
Net income attributable to the Partnership		$ 25,099	$ 14,860	$ 40,245	$ 32,607
Weighted average limited partner units outstanding (basic and diluted) (in units)		35,201,887	35,194,545	35,200,403	35,194,545
Distributions declared		$ 16,595	$ 16,590	$ 33,188	$ 33,181
Common units (in usd per share)		$ 0.71	$ 0.43	$ 1.14	$ 0.93
Cash Distribution | Common units
Distribution Made to Limited Partner [Line Items]
Distributions declared		$ 16,595	$ 16,590	$ 33,188	$ 33,181
Cash Distribution | Common And Subordinated Units [Member]
Distribution Made to Limited Partner [Line Items]
Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders (in usd per share)				$ 1.2938
Cash Distribution | Common And Subordinated Units [Member] | Subsequent Event
Distribution Made to Limited Partner [Line Items]
Distribution declared per unit (in usd per unit)	$ 0.4714
Above $1.2938 up to $1.4063 | Minimum
Distribution Made to Limited Partner [Line Items]
Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders (in usd per share)				1.2938
Above $1.2938 up to $1.4063 | Maximum
Distribution Made to Limited Partner [Line Items]
Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders (in usd per share)				$ 1.4063
Above $1.2938 up to $1.4063 | Unit Holders
Distribution Made to Limited Partner [Line Items]
Incentive Distribution, Marginal Percentage Interest in Distributions				85.00%
Above $1.2938 up to $1.4063 | IDR Holders
Distribution Made to Limited Partner [Line Items]
Incentive Distribution, Marginal Percentage Interest in Distributions				15.00%
Above $1.4063 up to $1.6875 | Minimum
Distribution Made to Limited Partner [Line Items]
Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders (in usd per share)				$ 1.4063
Above $1.4063 up to $1.6875 | Maximum
Distribution Made to Limited Partner [Line Items]
Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders (in usd per share)				$ 1.6875
Above $1.4063 up to $1.6875 | Unit Holders
Distribution Made to Limited Partner [Line Items]
Incentive Distribution, Marginal Percentage Interest in Distributions				75.00%
Above $1.4063 up to $1.6875 | IDR Holders
Distribution Made to Limited Partner [Line Items]
Incentive Distribution, Marginal Percentage Interest in Distributions				25.00%
Above $1.6875 | Minimum
Distribution Made to Limited Partner [Line Items]
Incentive Distribution Rights, Target Distribution Per Unit Requiring Marginal Percentage Distribution to IDR Holders (in usd per share)				$ 1.6875
Above $1.6875 | Unit Holders
Distribution Made to Limited Partner [Line Items]
Incentive Distribution, Marginal Percentage Interest in Distributions				50.00%
Above $1.6875 | IDR Holders
Distribution Made to Limited Partner [Line Items]
Incentive Distribution, Marginal Percentage Interest in Distributions				50.00%

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Distributions and Net Income Per Limited Partner Unit (Income In Excess Of Distribution) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Aug. 02, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership		$ 25,099	$ 14,860	$ 40,245	$ 32,607
Distributions declared		16,595	16,590	33,188	33,181
Net income in excess of distribution (distribution in excess of net income)		$ 8,504	$ (1,730)	$ 7,057	$ (574)
Distribution Made to Limited Partner, Distributions Paid, Per Unit		$ 0.4714	$ 0.4714	$ 0.9428	$ 0.9428
IDR Holders
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership		$ 0	$ 0	$ 0	$ 0
Distributions declared with respect to the incentive distribution rights		0	0	0	0
Net income in excess of distribution (distribution in excess of net income)		0	0	0	0
Common units
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership		25,099	14,860	40,245	32,607
Distributions declared		16,595	16,590	33,188	33,181
Net income in excess of distribution (distribution in excess of net income)		8,504	(1,730)	7,057	(574)
Cash Distribution | Common units
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Distributions declared		$ 16,595	$ 16,590	$ 33,188	$ 33,181
Cash Distribution | Common And Subordinated Units [Member] | Subsequent Event
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Distribution declared per unit (in usd per unit)	$ 0.4714

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Distributions and Net Income Per Limited Partner Unit (Basic and Diluted Income Per Limited Partner Unit) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Limited Partners' Capital Account [Line Items]
Distributions declared	$ 16,595	$ 16,590	$ 33,188	$ 33,181
Net income in excess of distribution (distribution in excess of net income)	8,504	(1,730)	7,057	(574)
Net income	$ 25,099	$ 14,860	$ 40,245	$ 32,607
Weighted average limited partner units outstanding (basic and diluted) (in units)	35,201,887	35,194,545	35,200,403	35,194,545
Common units
Limited Partners' Capital Account [Line Items]
Distributions declared	$ 16,595	$ 16,590	$ 33,188	$ 33,181
Net income in excess of distribution (distribution in excess of net income)	8,504	(1,730)	7,057	(574)
Net income	$ 25,099	$ 14,860	$ 40,245	$ 32,607
Weighted average limited partner units outstanding (basic and diluted) (in units)	35,201,887	35,194,545	35,200,403	35,194,545
Weighted average units outsanding:
Common units (in usd per share)	$ 0.71	$ 0.43	$ 1.14	$ 0.93
IDR Holders
Limited Partners' Capital Account [Line Items]
Subsequent distribution to IDR holders	$ 0	$ 0	$ 0	$ 0
Net income in excess of distribution (distribution in excess of net income)	0	0	0	0
Net income	$ 0	$ 0	$ 0	$ 0

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Distributions and Net Income Per Limited Partner Unit (Distribution Per Common Unit) (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Distribution Per Common Unit [Abstract]
Distribution Made to Limited Partner, Distributions Paid, Per Unit	$ 0.4714	$ 0.4714	$ 0.9428	$ 0.9428

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Partners' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 29, 2019	Oct. 04, 2018	Aug. 04, 2014
Class of Stock [Line Items]
Partners Units, Maximum Aggregate Offering Amount, ATM		$ 50
Limited Partner
Class of Stock [Line Items]
Number of units sold in public offering	2,940,818		12,937,500
Units sold in secondary offering price per unit (in dollars per share)	$ 21.40
Affiliated Entity
Class of Stock [Line Items]
Partners' Capital Account, Units, Sold to Related Party	1,401,869

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Related Party Transactions (Sales to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 240,956	$ 227,431	$ 460,759	$ 442,259

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Related Party Transactions (Cost of Sales from Related Parties) (Details) - Affiliated Entity - Westlake - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Related Party Transaction [Line Items]
Charges from related parties in cost of sales	$ 128,445	$ 93,222	$ 242,403	$ 176,960
Feedstock Purchased
Related Party Transaction [Line Items]
Charges from related parties in cost of sales	100,979	69,324	183,095	128,962
Other service charges
Related Party Transaction [Line Items]
Charges from related parties in cost of sales	$ 27,466	$ 23,898	$ 59,308	$ 47,998

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Related Party Transactions (Services from Related Parties Included in SG&A Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Services received from Westlake and included in selling, general and administrative expenses	$ 7,000	$ 5,698	$ 14,912	$ 10,813

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Related Party Transactions (Goods and Services Purchased from Westlake and Capitalized as Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Goods and services purchased from Westlake and capitalized as assets	$ 533	$ 384	$ 936	$ 864

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Related Party Transactions (Accounts Receivable from and Accounts Payable to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Receivable under the Investment Management Agreement—Westlake Chemical Corporation ("Westlake")	$ 222,249		$ 222,249		$ 123,228
Accounts payable—Westlake	20,134		20,134		7,855
Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Interest earned related to the IMA	$ 77	$ 219	$ 145	$ 807
Accounts receivable—Westlake, current and non-current					$ 108,028

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Related Party Transactions (General) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Buyer deficiency fee and shortfall	$ 8,742		$ 18,420
Buyer deficiency fee					$ 69,555
IMA, Partnership earned amount added to market rate, basis points			five
Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Interest earned related to the IMA	77	$ 219	$ 145	$ 807
Operating lease expense	608	$ 726	1,295	$ 1,396
Accrued Liabilities | Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Accrued interest included in receivable under IMA	$ 77		$ 77		$ 56

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Related Party Transactions (Debt Payable to Related Parties) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Interest on related party debt payable	$ 2,224	$ 3,431	$ 4,460	$ 7,381
Long-term debt payable to Westlake	399,674		399,674		$ 399,674
Other income (expense) | Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Interest on related party debt payable	2,224	$ 3,431
Accrued Liabilities | Affiliated Entity | Westlake
Related Party Transaction [Line Items]
Accrued interest on related party debt	$ 2,224		$ 2,224		$ 2,336

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Related Party Transactions (Site Lease Agreements) (Details)	6 Months Ended
	Jun. 30, 2021 USD ($)
Related Party Transaction [Line Items]
Site lease agreement, number	2
Site lease agreements, term (in years)	50
Site lease agreements, OpCo annual obligation to WLK	$ 1

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Related Party Transactions (Major Customer and Concentration Risk) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Affiliated Entity | Westlake | Revenue Benchmark | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration Risk, Percentage	74.80%	95.40%	78.00%	90.40%

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Long-term Debt Payable to Westlake (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Long-term debt payable to Westlake	$ 399,674	$ 399,674
Weighted average interest rate	2.20%	2.20%
Limited Partner | OpCo Revolver | Senior Unsecured Revolving Credit Facility
Related Party Transaction [Line Items]
Long-term debt payable to Westlake	$ 22,619	$ 22,619
Limited Partner | OpCo Revolver | Senior Unsecured Revolving Credit Facility | LIBOR [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent	2.00%
Limited Partner | MLP Revolver | Senior Unsecured Revolving Credit Facility
Related Party Transaction [Line Items]
Long-term debt payable to Westlake	$ 377,055	$ 377,055
Limited Partner | MLP Revolver | Senior Unsecured Revolving Credit Facility | LIBOR [Member]
Related Party Transaction [Line Items]
Basis spread on variable rate, percent	2.00%

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Fair Value Measurements (Summary of Carrying and Fair Values of Long Term Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt payable to Westlake, carrying value	$ 399,674	$ 399,674
OpCo Revolver | Senior Unsecured Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt payable to Westlake, fair value	22,924	23,301
OpCo Revolver | Senior Unsecured Revolving Credit Facility | Limited Partner
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt payable to Westlake, carrying value	22,619	22,619
MLP Revolver | Senior Unsecured Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt payable to Westlake, fair value	379,868	383,284
MLP Revolver | Senior Unsecured Revolving Credit Facility | Limited Partner
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt payable to Westlake, carrying value	$ 377,055	$ 377,055

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Supplemental Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accrued Liabilities [Abstract]
Accrued and other liabilities	$ 16,084		$ 18,768
Accrued taxes	3,925		6,207
Accrued maintenance	3,025		3,905
Accrued capital expenditures	2,823		$ 2,286
Increase (reduction) in capital expenditure accrual	$ 669	$ 182