Revenue Recognition	6 Months Ended
Oct. 31, 2017
Text Block [Abstract]
Revenue Recognition	B. Revenue Recognition Product sales and installation revenue are recognized when all of the following criteria have been met: (1) products have been shipped, or customers have purchased and accepted title to the goods, but because of construction delays, have requested that the Company temporarily store the finished goods on the customer’s behalf; service revenue for installation of products sold is recognized as the installation services are performed, (2) persuasive evidence of an arrangement exists, (3) the price to the customer is fixed, and (4) collectability is reasonably assured. The Company utilizes either the percentage of completion or completed contract method based on facts and circumstances of individual contracts. Deferred revenue consists of customer deposits and advance billings of the Company’s products where sales have not yet been recognized. Shipping and handling costs are included in cost of product sales. Because of the nature and quality of the Company’s products, any warranty issues are determined in a relatively short period after the sale and are infrequent in nature, and as such, warranty costs are immaterial to the Company’s consolidated financial position and results of operations and are expensed as incurred. Product sales resulting from fixed-price construction contracts involve a signed contract for a fixed price to provide the Company’s laboratory furniture and fume hoods for a construction project. In these instances, the Company is usually in the role of a subcontractor, but in some cases may enter into a contract directly with the end-user of the products. Contract arrangements normally do not contain a general right of return relative to the delivered items. Product sales resulting from fixed-price construction contracts are generated from multiple-element arrangements that require separate units of accounting and estimates regarding the fair value of individual elements. The Company has determined that its multiple-element arrangements that qualify as separate units of accounting are (1) product sales and (2) installation services. There is objective and reliable evidence of fair value for both the product sales and installation services and allocation of arrangement consideration for each of these units is based on their relative fair values. Each of these elements represent individual units of accounting, as the delivered item has value to a customer on a stand-alone basis. The Company’s products are regularly sold on a stand-alone basis to customers which provides either best estimate of selling prices or vendor-specific objective evidence of fair value. The fair value of installation services is separately calculated using expected costs of installation services. Many times the value of installation services is calculated using price quotations from subcontractors to the Company who perform installation services on a stand-alone basis. Product sales resulting from purchase orders involve a purchase order received by the Company from its dealers or stocking distributor. This category includes product sales for standard products, as well as products which require some customization. Any customization requirements are approved by the customer prior to manufacture of the customized product. Sales from purchase orders are recognized under the terms of the purchase order which generally are freight on board (“FOB”) shipping point and do not include rights of return. Accordingly, these sales are recognized at the time of shipment.

B. Revenue Recognition

Product sales and installation revenue are recognized when all of the following criteria have been met: (1) products have been shipped, or customers have purchased and accepted title to the goods, but because of construction delays, have requested that the Company temporarily store the finished goods on the customer’s behalf; service revenue for installation of products sold is recognized as the installation services are performed, (2) persuasive evidence of an arrangement exists, (3) the price to the customer is fixed, and (4) collectability is reasonably assured. The Company utilizes either the percentage of completion or completed contract method based on facts and circumstances of individual contracts.

Deferred revenue consists of customer deposits and advance billings of the Company’s products where sales have not yet been recognized. Shipping and handling costs are included in cost of product sales. Because of the nature and quality of the Company’s products, any warranty issues are determined in a relatively short period after the sale and are infrequent in nature, and as such, warranty costs are immaterial to the Company’s consolidated financial position and results of operations and are expensed as incurred.

Product sales resulting from fixed-price construction contracts involve a signed contract for a fixed price to provide the Company’s laboratory furniture and fume hoods for a construction project. In these instances, the Company is usually in the role of a subcontractor, but in some cases may enter into a contract directly with the end-user of the products. Contract arrangements normally do not contain a general right of return relative to the delivered items. Product sales resulting from fixed-price construction contracts are generated from multiple-element arrangements that require separate units of accounting and estimates regarding the fair value of individual elements. The Company has determined that its multiple-element arrangements that qualify as separate units of accounting are (1) product sales and (2) installation services. There is objective and reliable evidence of fair value for both the product sales and installation services and allocation of arrangement consideration for each of these units is based on their relative fair values. Each of these elements represent individual units of accounting, as the delivered item has value to a customer on a stand-alone basis. The Company’s products are regularly sold on a stand-alone basis to customers which provides either best estimate of selling prices or vendor-specific objective evidence of fair value. The fair value of installation services is separately calculated using expected costs of installation services. Many times the value of installation services is calculated using price quotations from subcontractors to the Company who perform installation services on a stand-alone basis.

Product sales resulting from purchase orders involve a purchase order received by the Company from its dealers or stocking distributor. This category includes product sales for standard products, as well as products which require some customization. Any customization requirements are approved by the customer prior to manufacture of the customized product. Sales from purchase orders are recognized under the terms of the purchase order which generally are freight on board (“FOB”) shipping point and do not include rights of return. Accordingly, these sales are recognized at the time of shipment.