Inventories - Schedule of Inventories (Details) - USD ($)	Apr. 30, 2017	Apr. 30, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 1,579,000	$ 1,948,000
Work in process	442,000	641,000
Finished goods	356,000	448,000
Inventory gross	2,377,000	3,037,000
Less: allowance for obsolete inventory	(73,000)	(73,000)
Totals	$ 2,304,000	$ 2,964,000

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02.6(a))
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-Name Accounting Standards Codification
-Topic 330
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-Section 35
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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount of valuation reserve for inventory.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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