BUSINESS SEGMENT DATA (Details) (USD $)	3 Months Ended		9 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 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	$ 29,761,356	$ 25,245,131	$ 82,965,659	$ 71,764,377
Income (loss) from operations	4,249,747	3,003,212	8,416,744	7,308,681
Identifiable assets	117,040,056		117,040,056		115,509,215
Product Recovery/Pollution Control Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	13,604,696	11,893,296	37,298,932	29,851,166
Income (loss) from operations	933,815	1,064,314	21,586	534,986
Identifiable assets	41,305,110		41,305,110		36,444,763
Fluid Handling Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	10,634,005	7,346,897	28,349,511	24,307,152
Income (loss) from operations	3,116,729	1,747,678	7,864,387	5,890,077
Identifiable assets	20,220,234		20,220,234		19,290,035
Mefiag Filtration Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	3,037,013	3,286,624	9,412,344	9,630,925
Income (loss) from operations	123,525	127,022	419,338	517,572
Identifiable assets	14,995,354		14,995,354		14,017,572
Filtration/Purification Technologies [Member]
Segment Reporting Information [Line Items]
Number of operating segments			2
Net sales	2,485,642	2,718,314	7,904,872	7,975,134
Income (loss) from operations	75,678	64,198	111,433	366,046
Identifiable assets	8,071,433		8,071,433		8,368,652
Total Operating Segments [Member]
Segment Reporting Information [Line Items]
Identifiable assets	84,592,131		84,592,131		78,121,022
Corporate [Member]
Segment Reporting Information [Line Items]
Identifiable assets	$ 32,447,925		$ 32,447,925		$ 37,388,193