Precautions for valve installation

During valve installation, in order to prevent metal, sand and other foreign matters from invading the valve and damaging the sealing surface, it is necessary to set a filter and a flushing valve; In order to maintain compressed air purification, an oil-water separator shall be set in front of the valve

Precautions for valve installation

During valve installation, in order to prevent metal, sand and other foreign matters from invading the valve and damaging the sealing surface, it is necessary to set a filter and a flushing valve; In order to maintain compressed air purification, an oil-water separator or an air filter shall be set in front of the valve; Considering that the working state of the valve can be checked during operation, it is necessary to set instruments and check valves; In order to maintain the operating temperature, thermal insulation facilities shall be set outside the valve; For installation behind the valve, safety valve or check valve shall be set; In consideration of the continuous operation of the valve and the convenience of danger, a parallel system or bypass system is set up.

1.protective facilities of check valve

In order to prevent the leakage of the check valve or the backflow of the medium after its failure, which may cause the decline of the product quality and cause accidents and other adverse consequences, one or two shut-off valves are set before and after the check valve. If two shut-off valves are set, the check valve can be easily removed for maintenance.

2. protective facilities of safety valve

The isolating valve is generally not set before and after the installation method, and can only be used in individual cases. If the medium force contains solid particles, which affects the safety valve cannot be closed tightly after taking off, a gate valve with lead seal shall be installed at the front and back of the safety valve. The gate valve shall be in the fully open state. The gate valve and the safety valve shall be directly installed with a DN20 inspection valve to the atmosphere.

When the released wax and other media are in solid state at normal temperature, or the temperature of light liquid and other media is lower than 0 ℃ due to decompression gasification, the safety valve needs steam tracing.

For safety valves used in corrosive media, corrosion-resistant explosion-proof film shall be added at the valve inlet according to the corrosion resistance of the valve.

The gas safety valve is generally provided with a bypass valve according to its diameter for manual venting.

3. protective facilities of pressure reducing valve

Pressure reducing valve installation facilities generally have three forms. Pressure gauges are installed at the front and rear of the pressure reducing valve to facilitate the observation of the pressure in front of and behind the valve. There is also a fully enclosed safety valve behind the valve to prevent 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. It is mainly used for the flushing of the drainage river. Some use steam traps. The main function of the bypass pipe is to close the shut-off valves in front of and behind the pressure reducing valve, open the bypass valve, manually adjust the flow, and play the role of temporary circulation when the pressure reducing valve fails, so as to facilitate the maintenance of the pressure reducing valve or the replacement of the pressure reducing valve.

4. protective facilities of steam trap

There are two types of steam traps with and without bypass pipes, including condensate recovery and non recovery payment. Steam traps with drainage capacity up to and other special requirements can be installed in parallel.

The drain valve with bypass valve is mainly used to discharge a large amount of condensate when the pipeline starts to operate. It is inappropriate to discharge condensate with bypass pipe during maintenance of drain valve, which will cause steam to flow into return water system. In general, bypass pipe may not be installed. Only when there are strict requirements on heating temperature, the heat equipment for continuous production shall be equipped with bypass pipe