I. Pre-installation Preparation
1. Check the valve specification model, pressure level, and flow direction identification to ensure that it meets the design requirements.
2. Check the cleanliness of the valve body cavity and remove packaging protective materials and foreign matter.
3. Butt welding connection valves need to be prefabricated with grooves, and flange connection valves need to check the integrity of the sealing surface.
II. Installation Direction Control
1. The globe valve and vertical lift check valve must be installed strictly in the direction indicated by the arrow on the valve body.
2. In principle, non rising stem valve, water type butterfly valve, and ball valves can be installed in both directions, but attention should be paid to ease of operation.
3. Electric / pneumatic valves need to reserve space for actuator operation and maintenance.
III. Welding Installation Specifications
1. The butt welding valve should be kept half-open during welding to prevent jamming caused by thermal deformation.
2. Use argon arc welding to make the base, and control the interlayer temperature not to exceed the rated temperature of the valve.
3. After welding, the valve must be functionally tested to confirm that it opens and closes normally.
IV. Key Points of Flange Connections
1. The flange sealing surfaces remain parallel, and the maximum allowable deviation does not exceed 0.15% of the flange outer diameter.
2. The gasket should be placed in the center, the bolts should be tightened symmetrically and evenly, and the rated torque should be reached in three times.
3. The connecting bolts of high-temperature valves should be tightened twice in a hot state.
V. Quality Control
1. Strength test and sealing test are required after installation.
2. When flushing the system, the regulating valve, flow meter and other equipment should be bypassed.
3. Fill in the installation record, including key data such as valve position number, test pressure, operating torque, etc.
Note: The valve must not be used as a support point for the pipeline. Large valves require a separate support frame. After installation, the valve should be in the fully closed position and protected to avoid cross-operation damage.
Post time: Feb-05-2026
