... valve 1.19years experience 2.low leakagerate,high quality 3.OEM is welcome 4.CE High quality Anti-sweat worm gear butterfly valve Model ... .6suitable medium Air, water, sewage, steam, gas, oil, etc. Drive type Manual, worm worm gear drive, gas drive, electric drive. Part ... , quick 90 degree on-off operation. 3.Disc has two-way bearing, perfect seal, without leakage under the pressure test. 4 ...