少妇无码太爽了视频在线播放,h动画在线看,一区二区三区无码高清视频,а√最新版资源在线官网

Professional design 4 inch ball valve

Ball Valve: application of medium is water, steam,non-corrosive gas, liquid. This unique structure has its own advantages, such as the switch without friction, resistance to wear, short torque, it can regulate media and cut tightly . Widely used in petroleum, chemical industry, urban water supply and drainage and other working conditions which need to cut off tighly.