Note 4 - Revenue Recognition - Revenues by Revenue Class (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2022	Jan. 31, 2021
Sales by product	$ 138,552	$ 84,694
Sales by product, percent	100.00%	100.00%
Product [Member] \| Transferred at Point in Time [Member]
Sales by product	$ 13,575	$ 11,496
Sales by product, percent	10.00%	14.00%
Specialty Piping Systems And Coating [Member] \| Transferred at Point in Time Using Input Method [Member]
Sales by product	$ 44,778	$ 35,041
Sales by product, percent	32.00%	41.00%
Specialty Piping Systems And Coating [Member] \| Transferred at Point in Time Using Output Method [Member]
Sales by product	$ 80,199	$ 38,157
Sales by product, percent	58.00%	45.00%

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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+ Details