1. The installation position, height, and direction of import and export must meet the design requirements, and the connection should be firm and tight. All kinds of manual valves installed on the thermal insulation pipeline, the handle shall not be downward.
2. Visual inspection must be carried out before the valve is installed, and the nameplate of the valve should comply with the current national standard "General Valve Mark" GB 12220. For the valve whose working pressure is greater than 1.0 MPa and plays the role of cutting off the main pipe, the strength and tight performance test should be carried out before installation, and it is allowed to be used after passing the test. During the strength test, the test pressure is 1.5 times the nominal pressure, and the duration is not less than 5 minutes. The valve housing and packing should be qualified without leakage. During the tightness test, the test pressure is 1.1 times the nominal pressure; the test pressure should meet the requirements of GB 50243 during the duration of the test, and the sealing surface of the valve disc is qualified if there is no leakage.