(Tables)

6 Months Ended

Jul. 31, 2013

Business segment reporting [Abstract]

Business segment reporting [Table Text Block]

	Three Months Ended July 31,						Six Months Ended July 31,
	2013			2012			2013			2012
Net sales
Piping systems		$43,478			$22,905			$79,536			$42,649
Filtration products	17,324			19,276			35,957			42,252
Corporate and Other	863			701			1,756			1,603
Total		$61,665			$42,882			$117,249			$86,504
Gross profit
Piping systems		$10,590			$4,869			$21,034			$8,267
Filtration products	2,842			2,552			5,117			5,664
Corporate and Other	261			162			509			398
Total		$13,693			$7,583			$26,660			$14,329
Income (loss) from operations
Piping systems		$6,493			$1,443			$11,873			$1,598
Filtration products	501			(292		)	18			(96		)
Corporate and Other	(2,224		)	(1,754		)	(4,231		)	(3,967		)
Total		$4,770			($603	)		$7,660			($2,465	)