Provisions and installation requirements for the installation of thirty-five pipeline valves
Time: September 27, 2020 12:17:17 Source: Yonglong Valve Reading: zero second
Provisions and installation requirements for the installation of thirty-five pipeline valves
What are the regulations for the installation of pipeline valves? Do you still need to meet certain installation requirements? Generally, there is arrow direction indication on the valve body. Without arrow direction indication, it can be installed in any direction, such as butterfly valve and ball valve.
1. During installation, the flow direction of the medium shall be consistent with the arrow direction of the valve body.
2. A check valve shall be installed after the drain valve before the condensed water enters the recovery header to prevent the condensed water from backflow.
3. The rising stem valve cannot be buried to prevent the valve stem from rusting. In the trench with cover plate, the valve shall be installed at a place convenient for maintenance, inspection and operation.
4. For some pipelines requiring low water hammer impact or no water hammer when closing, it is better to select slow closing butterfly check valve and slow closing swing check valve.
5. When installing the threaded valve, it is necessary to ensure the integrity of the thread, apply sealing filler according to the different media, and tighten evenly to avoid damage to the valve and valve accessories.
6. During the installation of socket welding valves, there should be a gap of 1-2m between the socket and spigot to prevent the weld from cracking due to excessive thermal stress during welding.
7. When installing on the horizontal pipeline, the valve rod shall be vertically upward or inclined at an angle, and it is not allowed to install the valve rod downward.
8. The bottom layer of the connecting weld between the butt valve and the pipeline shall be welded by argon arc welding. The valve shall be opened during welding to prevent overheating and deformation.
9. Before installing the drain valve, the pipeline must be purged with pressurized steam to remove the sundries in the pipeline.
10. Do not install steam trap in series.
11. Diaphragm check valves are often used on pipelines prone to water hammer, because the diaphragm can well eliminate water hammer caused by medium countercurrent, but due to temperature and pressure limitations, they are generally used on low-pressure and normal temperature pipelines.
12. A filter shall be installed in front of the drain valve to ensure that the drain valve is not blocked by pipe debris, and the filter shall be cleaned regularly.
13. Valves connected by flanges and threads shall be closed during installation.
14. Condensate flow direction shall be consistent with the installation arrow mark of drain valve.
15. The drain valve shall be installed at the lowest point of the equipment outlet, and the condensed water shall be discharged in time to avoid steam resistance of the pipeline.
16. When installing flanged valves, ensure that the two flange end faces are parallel and concentric with each other.
17. Valves shall be installed in front of and behind the drain valve to facilitate the maintenance of the drain valve at any time.
18. Mechanical drain valve shall be installed horizontally.
19. In case of steam leakage of drain valve, drain and clean the filter screen in time, check frequently according to the actual use, and repair at any time in case of fault.
20. The check valve shall not bear weight in the pipeline. Large check valves shall be independently supported so that they are not affected by the pressure generated by the pipeline system.
21. The condensate recovery header behind the drain valve cannot climb, which will increase the back pressure of the drain valve.
22. If there is no drain valve installed at the lowest position of the equipment, a trap should be added at the lowest position of the water outlet to raise the condensate level before installing the drain valve to avoid steam resistance.
23. The outlet pipe of drain valve shall not be immersed in water.
24. If there is condensate recovery behind the drain valve, the drain valve outlet pipe shall be connected to the main pipe from above the recovery main pipe to reduce back pressure and prevent backflow.
25. Each equipment shall be equipped with a drain valve.
30. Lift type horizontal flap check valve shall be installed on the horizontal pipeline.
31. Install a drain valve on the steam pipeline. The main pipeline should be equipped with a condensate collecting well close to the radius of the main pipeline, and then use a small pipe to lead to the drain valve.
32. If there is condensate recovery behind the trap, separate recovery of pipelines with different levels of pressure is required.
33. Lift type vertical flap check valve shall be installed vertically.
34. When the mechanical drain valve is not used for a long time, it is necessary to remove the drain screw and drain the water inside to prevent freezing.
35. There should be more than one meter of non insulated supercooled pipe in front of the thermal static trap, and other traps should be as close to the equipment as possible.
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