The use of seals in three parts of the valve

The use of seals in three parts of the valve
Seals are also very critical components in valves. The sealing function of the valve refers to the ability of each sealing part of the valve to prevent the leakage of the mechanical sealing medium used in the kettle. It is the most 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 two sealing surfaces of the valve seat; the joint between the packing and the mechanical seal of the valve stem and the stuffing box; the connection between the valve body and the bonnet. The leakage in the first place is called internal leakage, which is generally referred to as lax closing, which will affect the ability of the valve to cut off the medium. For shut-off valves, internal leakage is not allowed. The leakage in 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. External leakage will cause material loss, pollute the environment, and even cause accidents in severe cases. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have a reliable sealing function.