Warranties

The Company has warranties with various terms from 18 months for parts to 25 years for certain heat exchangers. The Company has an obligation to replace parts or service its products if conditions under the warranty are met. A provision is made for estimated warranty costs at the time the related products are sold based upon the warranty period, historical trends, new products and any known identifiable warranty issues.

Changes in the warranty accrual are as follows:



	Years Ending December 31,
	2015			2014			2013
Warranty accrual:	(in thousands)
Balance, beginning of period	$	8,130		$	7,352		$	5,776
Payments made	(3,978		)	(4,096		)	(4,448		)
Provisions	4,317			4,874			6,005
Adjustments related to changes in estimates	—			—			19
Balance, end of period	$	8,469		$	8,130		$	7,352

Warranty expense:	$	4,317		$	4,874		$	6,024