... 2.low leakagerate,high quality 3.OEM is welcome 4.CE High quality Anti-sweat worm gear butterfly valve Model of valve:D371XBody of valve : cast ... medium Air, water, sewage, steam, gas, oil, etc. Drive type Manual, worm worm gear drive, gas drive, electric drive. Part ... leakage under the pressure test. 4.Flow curve tending to straight-line. Excellent regulation performance. 5.Various kinds of materials, ...