Valve Is a Attachment of Pipe

Valve is a attachment of pipe. It is used to change the channel section and flow direction of medium, it's a device for control the flowtransmission medium. Specifically, the valve has the following purposes: (1) For getting through or shutting off the media. Such as gate valve, globe valve, ball valves, plug valves, diaphragm valves, butterfly valves and so on. (2) For regulating, controlling the flow and pressure. Such as throttle, regulating valve, reducing valve, safety valve and so on. (3) For changing the direction. Such as the distribution of valves, three cocks, three, or four-way ball valve and so on. (4) For preventing backflow. A variety of different structures such as check valve, bottom valve. (5) For separating the medium. A variety of different structures, such as steam traps, air traps and so on. (6) For directing and regulating fluid levels. Such as liquid level indicators, liquid level regulator, etc... (7) For other special purposes. Such as temperature control valve, over-current protection of emergency shut-off valve and so on. As these variety of common valves abover-mentioned, the valves used for getting through or shutting off the media, the quantities actually used are 80% of total quantities used. Source: Valvehardware