1. The installation position, height, and direction of the inlet and outlet of the valve must meet the direction design requirements, and the connection should be firm and tight.
2. The valve can be connected to the pipeline with various types of ends. The most important connection methods are threaded, flanged and welded connections. When flange connection, if the temperature exceeds 350℃, it is due to bolts. Flanges and gaskets creep and relax, and high-temperature-resistant bolt materials should be selected.
3. The valve must be visually inspected before installation. The nameplate of the valve should comply with the current international standard GB12220 "General Valve Marking". For valves with a working pressure greater than 1.0MPA and a cut-off function on the main pipe, strength and tightness tests should be carried out, and they can be used only after they are qualified. Other valves do not need to be tested separately and will be tested in the system pressure test.
4. During the strength test, the test pressure shall be 1.5 times the nominal pressure, and the duration shall not be less than 5 min. There should be no leakage of the valve shell and packing.
5. During the tightness test, the test pressure is 0.3mpa, and the test pressure should remain unchanged during the duration of the test. The time should meet the requirements of Table 2, and it is qualified that there is no leakage on the valve flap sealing surface.