... specifications:1) B21 (stop valve): D20, D25, D32, D40, D50, D632) B33 (ball valve): 1/2" x D20, 3/4" x D25, ... x D50, 1" x D63Applications:1) Cold, hot water supply facilities for public buildings2) Food, chemical, electronic industrial pipeline networks such ... as pipeline networks for transporting all kinds of corrosive liquid 3) Drinking water production system pipeline networks such ...