Protective facilities for check valves
In order to prevent the leakage of the check valve or the backflow of the medium after failure, which may cause the product quality to deteriorate and cause accidents and other undesirable consequences, one or two shut-off valves are installed before and after the check valve. If two shut-off valves are provided, the check valve can be easily disassembled and repaired.
2. Safety valve protection facilities
Block valves are generally not installed before and after the installation method, and can be used only in individual cases. If the medium force contains solid particles and affects that the safety valve cannot be closed tightly after taking off, a gate valve with a lead seal should be installed before and after the safety valve. The gate valve should be in a fully open state. The gate valve and the safety valve should be directly installed with a valve. Check valve to atmosphere.
When the vented wax and other media are in a solid state at room temperature, or when the temperature of the light liquid and other media is lower than 0 degrees Celsius due to reduced pressure gasification, the safety valve needs steam tracing. For safety valves used in corrosive media, depending on the corrosion resistance of the valve, consider adding a corrosion-resistant explosion-proof film at the valve inlet. The gas safety valve is generally equipped with a bypass valve according to its diameter for manual venting.
3. Protective facilities of pressure reducing valve
There are generally three types of pressure reducing valve installation facilities. Pressure gauges are installed before and after the pressure reducing valve to facilitate the observation of the pressure before and after the valve. There is also a fully enclosed safety valve behind the valve to prevent the pressure after the valve from jumping when the pressure behind the valve exceeds the normal pressure after the pressure reducing valve fails, including the system behind the valve. The drain pipe is installed in front of the shut-off valve in front of the valve, which is mainly used to flush the drainage river, and some use traps. The main function of the by-pass pipe is to close the shut-off valves before and after the pressure-reducing valve when the pressure-reducing valve fails, open the bypass valve, adjust the flow manually, and play a temporary circulation role, so as to repair the pressure-reducing valve or replace the pressure-reducing valve.
4. Protective facilities for traps
There are two types of bypass pipe and no bypass pipe on the side of the trap. There are condensate water recovery and condensate non-recovery payment, and the drainage capacity of traps and other special requirements can be installed in parallel.
A trap with a bypass valve is mainly used to discharge a large amount of condensate when the pipeline starts to run. When repairing the trap, it is not appropriate to use the bypass pipe to drain the condensate, as this will cause the steam to escape into the return water system. Under normal circumstances, the bypass pipe is not required. Only when there are strict requirements on the heating temperature, the heating equipment for continuous production is equipped with a bypass pipe.
