During the installation of the valve, in order to maintain the prevention of metal, sand and other foreign substances invade the valve and damage the sealing surface, it is necessary to install a filter and a flush valve; in order to maintain the compressed air purification, an oil-water separator or an air filter needs to be provided in front of the valve; Taking into account the operation of the valve can check the working status, the need to set the instrument and check valve; In order to maintain the operating temperature, in the valve outside the installation of insulation facilities; In order to install the valve, you need to set the safety valve or check valve; taking into account the continuous operation of the valve , To facilitate the danger, set up a parallel system or bypass system.
1. Check valve protection: In order to prevent leakage of the check valve or reverse flow of the medium after the failure, the quality of the product is reduced, resulting in accidents and other adverse consequences. One or two shut-off valves are provided before and after the check valve. If two shut-off valves are provided, the check valve can be easily removed for maintenance.
(2) Safety valve protection facilities: Generally, no block valve is installed before and after the installation method, and it can only be used in individual cases. If the media force contains solid particles, affecting the safety valve can not be tight after take-off, to install a seal valve before and after the safety valve, the valve should be in the fully open state, the valve and the safety valve directly installed a pass DN20 check valve to the atmosphere. When the media, such as evacuating wax, is solidified at room temperature, or when gasification under reduced pressure causes the temperature of a medium such as light liquid to fall below 0 degrees Celsius, the safety valve needs steam heating. For the safety valve of corrosive medium, depending on the corrosion resistance of the valve, consider adding a corrosion-resistant explosion-proof membrane at the valve inlet. The gas safety valve is generally provided with a bypass valve according to its diameter and used as a manual vent.
3. Pressure relief valve protection facilities: Pressure relief valve installation facilities generally have three forms. Pressure gauges are installed on the front and rear of the pressure relief valve to facilitate the observation of pressure before and after the valve. There is a fully enclosed safety valve behind the valve to prevent the valve from jumping when the pressure exceeds the normal pressure after the pressure relief valve fails. This includes the post-valve system. The drain pipe is installed in front of the valve shut-off valve, mainly for draining the river, and some with a trap. The main function of the bypass pipe is to close the shut-off valve before and after the decompression valve when the pressure reducing valve fails, open the bypass valve, and manually adjust the flow to play a temporary circulation function to repair the pressure reducing valve or replace the pressure reducing valve.
4. Trap protection facilities: There are two bypass pipes on the edge of the steam trap and no bypass pipe. There are traps for condensate recovery and non-recovery of condensate, and the discharge volume and other special requirements can be used in parallel. Form installation facilities. Traps with bypass valves are mainly used to discharge large amounts of condensate when the pipeline starts to operate. When the trap is serviced, it is not appropriate to use the bypass to drain the condensate. This will allow steam to enter the return system. Under normal circumstances, no bypass can be installed. Only strict requirements are imposed on the heating temperature, and the heat production equipment for continuous production is equipped with the bypass pipe.