For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Description of the types of products and services from which the reportable segment derives its revenue.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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The net result for the period of deducting operating expenses from operating revenues.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Business segment reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
Business segment reporting (Details) $ in Thousands	Jul. 31, 2016 USD ($) Segments	Jul. 31, 2015 USD ($)	Jul. 31, 2016 USD ($)	Jul. 31, 2015 USD ($)	Jan. 31, 2016
Segment reporting
Number of reportable segments \| Segments	1
Net sales	$ 22,859	$ 25,147	$ 45,928	$ 45,424
Gross profit	2,980	3,126	4,972	5,481
Loss from operations	(1,840)	(2,530)	$ (6,345)	(6,100)
Piping Systems [Member]
Segment reporting
Segment Reporting Information, Description of Products and Services			Piping Systems engineers, designs, manufactures and sells specialty piping, leak detection and location systems
Net sales	22,859	25,147	$ 45,928	45,424
Gross profit	2,980	3,126	4,972	5,481
Loss from operations	(714)	(825)	(2,415)	(2,251)
Corporate Segment [Member]
Segment reporting
Loss from operations	$ (1,126)	$ (1,705)	$ (3,930)	$ (3,849)
Credit Concentration Risk [Member]
Segment reporting
Concentration Risk, Percentage			16.00%		46.00%
Sales Revenue, Net [Member]
Segment reporting
Concentration Risk, Percentage		10.20%	10.70%