In the fluid system, the valve is a device used to control the direction, pressure and flow of the fluid. During the construction process, the quality of valve installation directly affects the normal operation in the future, so it must be highly valued by construction units and production units. 

 Technical requirements for valve installation 

 1. Directionality. Generally, there is a sign on the valve body of the valve, and the direction indicated by the arrow is the direction in which the gas flows forward. Special attention must be paid to not to pretend to be reversed. Because there are various valves that require one-way circulation of gas, such as safety valves, pressure reducing valves, check valves, throttle valves, etc. For shut-off valves, in order to facilitate opening and maintenance, gas is also required to pass through the seat from the bottom up, but when the gate valve and plug are installed, they are not limited by the direction of circulation. 

 2. Installation location. It is necessary to consider the long-term operation and maintenance of the valve, and make the operation and maintenance as convenient as possible. At the same time, we should pay attention to the beauty of the appearance during assembly. 

 The direction of the valve handle can be vertically upwards, or tilted to a certain angle or horizontally, but the handwheel must not be downwards to avoid face-up operation; the handwheel of the floor valve should be chest-high for easy opening and closing; the open rod gate valve cannot be used underground to prevent the valve stem from being corroded. 

 The installation position of some valves has special requirements. For example, the pressure reducing valve requires installation upright on the horizontal pipe and must not be tilted. The lifting check valve requires the valve disc to be vertical; the rotary check valve requires the pin shaft to be horizontal. In a word, the installation position of the valve should be determined according to the principle, otherwise the valve will not work effectively or even work. 

 3. Installation of screw plug. Check the specifications and models, identify whether there is any damage, remove the cover of the thread and excessive grease and debris in the thread, and check the sealing performance of the plug. When installing the gas plug, you must pay attention to the appropriate force, and choose pipe pliers or wrenches of different specifications according to the size of the plug. 

 4. When installing the thread buckle valve, the valve company should ensure that the thread is intact; use a wrench when it is possible to use a wrench, do not use pipe pliers to avoid damaging the appearance of the valve body. 

 5. The installation of flange valves must ensure that the cross-sections of the two flanges are parallel to each other and on the same axis. When tightening the bolts, they should be crosswise to ensure that the valve end surface is subjected to uniform force. 

 6. The valve connected to the flange and thread should be installed in the closed state. When the butt welding valve is connected to the pipeline, the bottom of the weld should be welded with argon welding to ensure the internal cleanliness. When welding, the valve should not be closed to prevent thermal deformation. 

 7. Under normal circumstances, the valve is directly connected to the corrugated expansion joint, so the pipes on both sides should be cut off and the installation position should be left according to the size of the valve and the corrugated expansion joint, as well as the flange and gasket. 

 8. When the valve is hoisted, the rope should not be tied to the first wheel or valve stem to prevent damage. It should be lifted and released lightly, and should not collide. When placed on the pier, the height should be stable and flat according to the required height. There must be a solid support or bracket under the valve to support the valve, and the valve should not be allowed to hang in the air to generate stress.