Note 4 - Revenue Recognition (Tables)

9 Months Ended

Oct. 31, 2018

Notes Tables

Disaggregation of Revenue [Table Text Block]

	Three Months Ended October 31,										Nine Months Ended October 31,
	2018					2017					2018					2017
	Sales		% to Total			Sales		% to Total			Sales		% to Total			Sales		% to Total
Products	$	4,440		14	%	$	2,504		9	%	$	9,447		10	%	$	5,830		7	%
Specialty Piping Systems and Coating
Revenue recognized under input method		11,869		36	%		10,986		40	%		32,778		35	%		34,240		44	%
Revenue recognized under output method		16,497		50	%		14,008		51	%		51,795		55	%		37,781		49	%
Total	$	32,806		100	%	$	27,498		100	%	$	94,020		100	%	$	77,851		100	%

Contract with Customer, Asset and Liability [Table Text Block]

	Contract Assets
Balance January 31, 2018	$	1,502
Costs and gross profit recognized during the period for uncompleted contracts from the prior period		(1,085	)
Costs and deferred gross profit incurred on uncompleted contracts not billed at the end of the current period		1,417
Closing Balance at April 30, 2018	$	1,834
Costs and gross profit recognized during the period for uncompleted contracts from the prior period		(1,395	)
Costs and deferred gross profit incurred on uncompleted contracts not billed at the end of the current period		1,575
Closing Balance at July 31, 2018	$	2,014
Costs and gross profit recognized during the period for uncompleted contracts from the prior period		(1,917	)
Costs and deferred gross profit incurred on uncompleted contracts not billed at the end of the current period		2,260
Closing Balance at October 31, 2018	$	2,357

	Contract Liabilities
Balance January 31, 2018	$	1,967
Revenue recognized during the period for uncompleted contracts from the prior period		(1,810	)
New contracts entered into that are uncompleted at the end of the current period		413
Closing Balance at April 30, 2018	$	570
Revenue recognized during the period for uncompleted contracts from the prior period		(422	)
New contracts entered into that are uncompleted at the end of the current period		398
Closing Balance at July 31, 2018	$	546
Revenue recognized during the period for uncompleted contracts from the prior period		(497	)
New contracts entered into that are uncompleted at the end of the current period		1,550
Closing Balance at October 31, 2018	$	1,599