BUSINESS SEGMENT DATA (Details) (USD $)	3 Months Ended		6 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012	Jul. 31, 2011	Jan. 31, 2012
Segment Reporting Information [Line Items]
Number of operating segments			5
Number of reportable segments			3
Number of other segments			1
Net sales	$ 27,997,242	$ 23,089,343	$ 53,204,303	$ 46,519,246
Income (loss) from operations	2,420,141	2,222,493	4,166,997	4,305,469
Identifiable assets	112,778,587		112,778,587		115,509,215
Product Recovery/Pollution Control Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	13,193,396	9,625,898	23,694,236	17,957,870
Income (loss) from operations	(469,167)	(49,043)	(912,229)	(529,328)
Identifiable assets	37,284,193		37,284,193		36,444,763
Fluid Handling Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	8,315,307	7,407,151	17,715,506	16,960,255
Income (loss) from operations	2,363,288	1,901,703	4,747,658	4,142,399
Identifiable assets	18,815,811		18,815,811		19,290,035
Mefiag Filtration Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	3,523,165	3,204,384	6,375,331	6,344,301
Income (loss) from operations	367,901	169,078	295,813	390,550
Identifiable assets	14,916,983		14,916,983		14,017,572
Filtration/Purification Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	2,965,374	2,851,910	5,419,230	5,256,820
Income (loss) from operations	158,119	200,755	35,755	301,848
Identifiable assets	8,419,428		8,419,428		8,368,652
Total Operating Segments [Member]
Segment Reporting Information [Line Items]
Identifiable assets	79,436,415		79,436,415		78,121,022
Corporate [Member]
Segment Reporting Information [Line Items]
Identifiable assets	$ 33,342,172		$ 33,342,172		$ 37,388,193