亚洲的天堂精品_国产电影免费在线看_孕妇奶水仑乱A级毛片在线播放_阿v网站观看i免费观看。_97午夜福利影院_一级137片内射偷拍_国产精品动漫视频网站_午夜伦理在线视频_欧美v片天堂色资源网经_欧美 自拍偷拍

Globe valve

Globe valve, also known as cut-off valve, is a mandatory sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak. When the medium enters the valve from under the valve disc, the resistance that the operating force needs to overcome is the friction force between the valve stem and the packing and the thrust generated by the pressure of the medium. The force to close the valve is greater than the force to open the valve, so the valve stem The diameter of the valve should be large, otherwise the failure of the top of the valve stem will occur.