Business segment (Tables)

6 Months Ended

Jul. 31, 2017

Segment Reporting [Abstract]

Business segment reporting [Table Text Block]

	Three Months Ended July 31,						Six Months Ended July 31,
	2017			2016			2017			2016
Net sales
Piping Systems		$26,852			$22,859			$50,353			$45,928
Gross profit
Piping Systems		$3,058			$2,980			$4,843			$4,972
Loss from operations
Piping Systems		$62			($714	)		($1,397	)		($2,415	)
Corporate		($2,167	)		($1,476	)	(4,525		)	(4,375		)
Total loss from operations		($2,105	)		($2,190	)		($5,922	)		($6,790	)