Midwesco Filter Resources, Inc.  (Original Public Co. 12'89)
400 Battaile Drive
Winchester, Virginia
(540) 667-8500

	TDC Filter, Inc.  (Acquired 12/3/97) 1331South 55th Court Cicero, IL  60804 (708) 863-4400
	Nordic Air Filtration A/S (Acquired 11/2/98) Perlestikkergade 23H DK-4900 Nakskov, Denmark 45-5495-1390
	Nordic Midwesco (Acquired April 2006) 158 1st Avenue Vorsterskroon Nigel, Republic of South Africa 27-11-814-8361

Perma-Pipe, Inc.  (Acquired 1/20/94)

Business offices: 7720 N. Lehigh Avenue Niles, IL  60714   (847) 966-2235

Manufacturing Plant: 1310 Quarles Drive  Lebanon, TN  37087 (615) 444-4910

Perma-Pipe Middle East, FZE   P.O. Box 4988 Fujairah, U.A.E. 971-9-228-2540

Thermal Care, Inc.  (Acquired 12/30/96)
7720 N. Lehigh Avenue
Niles, IL  60714
(847) 966-2260

	Boe-Therm A/S  (Acquired 6/1/98) Industrivaenget 1 DK-5610 Assens, Denmark
	AWS (Acquired July 2002) 7720 N. Lehigh Avenue Niles, IL  60714 (847) 929-1950