Airgas, Inc., Radnor, PA, has acquired Wright Welding Supply, Inc., an industrial gas and welding supply distributor in Des Moines, IA, and two other distributors in Texas and British Columbia. Together, the three transactions add $22 million in acquired annual sales.   ; Wright Welding Supply, Inc. operates in Iowa and eastern Nebraska from five locations in Des Moines, Fort Dodge, Oskaloosa, and Council Bluffs, IA; and Omaha, NE, with an industrial and specialty gas fill plant in Des Moines. The operations, with about 40 employees, have been integrated into Airgas North Central, one of the regional companies within Airgas.   ; In Texas, Airgas has acquired Basin Welding Supply in Odessa, TX. Basin's new fill plant in Odessa, which opened in February 2007, will improve capabilities to fill packaged gases for customers in Odessa and the surrounding area.   ; In British Columbia, Airgas has acquired Mainland Welding Supplies Ltd., based in Surrey, BC, near Vancouver. The gases and welding distributor have joined Airgas Canada, which operates in western Canada as part of the Airgas Nor Pac region.   ; Airgas, Inc. is a U.S. distributor of industrial, medical, and specialty gases, and hardgoods, such as welding equipment and supplies. Airgas is also a distributor of safety products, producer of nitrous oxide and dry ice, liquid carbon dioxide producer, and a distributor of process chemicals, refrigerants, and ammonia products.