Babcock & Wilcox (NYSE:BWC) says it has completed its $155 million purchase of environmental products manufacturer MEGTEC Systems Inc. MEGTEC, based in Wisconsin, manufactures air pollution and energy storage equipment. It employs 600 in the United States, Canada, Europe, India, Australia and China. It generated revenue of $176 million in 2013. B&W announced in May that its subsidiary B&W Power Generation Group had agreed to buy the company. Execs remain Randall Data, president and chief operating…