1. The installation position, height, and entrance and exit directions must meet the design requirements, and the connections should be firm and tight. The handles of various manual valves installed on insulated pipes must not be downwards.
2. Appearance inspection must be carried out before the valve is installed. The nameplate of the valve should comply with the current national standard "General Valve Marking" GB 12220. For valves with a working pressure greater than 1.0 MPa and which function as a cut-off on the main pipe, strength and tightness performance tests should be carried out before installation, and they can only be used after passing the test. During the strength test, the test pressure is 1.5 times the nominal pressure and the duration is no less than 5 minutes. The valve shell and packing should be free of leakage to be qualified. During the tightness test, the test pressure is 1.1 times the nominal pressure; the test pressure should meet the requirements of the GB 50243 standard for the duration of the test, and it is qualified if there is no leakage on the sealing surface of the valve disc.