Instrument valve is a device to control the flow of conveying medium

Instrument valve is a device to control the flow of conveying medium
Instrument valve is a device used to change the channel section and medium flow direction, and control the medium flow. The sealing performance of instrument valve refers to the ability of the sealing parts of instrument valve to prevent medium leakage, which is an important technical performance index of instrument valve. There are three sealing parts of the instrument valve: the contact between the opening and closing parts and the two sealing surfaces of the valve seat; The matching place of packing, valve stem and stuffing box; The joint between valve body and valve cover. One of the previous leakage is called internal leakage, which is usually said to be not closed tightly, it will affect the ability of instrument valve to cut off the medium. For block valves, internal leakage is not allowed. The leakage of the latter two places is called external leakage, that is, the medium leaks from the inside of the valve to the outside of the valve. Leakage will cause material loss, pollute the environment, and even cause accidents. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so instrument valves need to have reliable sealing performance.