The use of the valve is extensive, so it plays a great role. For example, in power plants, valves can control the operation of boilers and steam turbines; In petroleum and chemical production, valves also control the normal operation of all production equipment and processes. The same is true in other departments. Despite this, valves are often overlooked when compared with other products. For example, when installing machine equipment, people often focus on the main machine equipment, but ignore the valve. This will reduce the overall production efficiency or stop production, or cause a variety of other accidents. Therefore, the selection, installation, use of valves must be carried out seriously and responsibly. Domestic commonly used general gate valve, globe valve, throttle valve, instrument valve, plunger valve, diaphragm valve, plug valve, ball valve, butterfly valve, check valve, pressure reducing valve safety valve, trap valve, regulating valve, bottom valve, filter, blowdown valve, etc.
The sealing performance of the valve refers to the ability of each sealing part of the valve to prevent the leakage of the medium, which is an important technical performance indicator of the valve. There are three sealing parts of the valve: the contact between the opening and closing parts and the sealing surface of the valve seat; The fitting of packing with valve stem and packing box; The connection between the valve body and the valve cover. The leakage in the first place is called internal leakage, which is usually referred to as lax closing, which will affect the ability of the valve to cut off the medium. For cut-off valves, internal leakage is not allowed. The latter two leaks are called external leaks, that is, the medium leaks from inside the valve to outside the valve. Leakage will cause material loss, pollute the environment, and cause accidents in serious cases. For flammable and explosive, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance
