Sealing requirements
The sealing performance of the valve refers to the ability of the sealing parts of the valve to prevent the leakage of the medium. It is the most important technical performance index of the valve. There are three sealing parts of the valve: the contact between the sealing surface of the opening and closing parts and the valve seat; the joint of the packing with the valve stem and the stuffing box; the connection between the valve body and the valve cover. The leak in the former place is called endoleak, which is commonly referred to as the lack of tightness, which will affect the ability of the valve to cut off the medium. For shut-off valves, internal leakage is not allowed. The latter two leaks are called external leaks, ie the medium leaks from the valve to the outside of the valve. External leakage can cause material loss, pollute the environment, and cause accidents in severe cases. For flammable, explosive, toxic or radioactive media, external leakage is not allowed, so the valve must have a reliable sealing performance.
other requirements
1. The assembled valve is purged with nitrogen for at least 1 minute.
2. The airtight test must be pure nitrogen.
3. After the airtight test is passed, encapsulation is carried out, sealed with a clean polyethylene cap, and the polyethylene cap is soaked with an organic solvent before use and wiped clean.
4. Then seal with a vacuum bag.
5, finally packing.
6. Measures should be taken during transportation to ensure that the envelope is not damaged.
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