Generally, there is no block valve at the front and back of the safety valve. Only in some cases, the block valve is set at the front and back of the safety valve. If the medium contains solid impurities that affect the safety valve cannot be closed tightly after it takes off, a gate valve with lead seal shall be installed in front of the safety valve. A DN20 inspection valve with atmospheric diameter shall be installed between the gate valve and the safety valve in the fully open position.

When the wax, phenol and other media discharged by the safety valve are solid at normal temperature, or the temperature of light liquid hydrocarbon and other media is lower than 0 ℃ due to decompression and vaporization, the safety valve needs to be added with 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.

Generally, a by-pass valve is set for the gas safety valve according to its diameter for manual venting.

Protection facilities of check valve

In order to prevent the medium backflow after the leakage or failure of the check valve, one or two shut-off valves shall be set at the front and back of the check valve. If two shut-off valves are set, the check valve can be easily removed for maintenance.

Protection facilities of steam trap

Steam trap has by-pass pipe and no by-pass pipe; condensate recovery and condensation non recovery. For steam traps with large drainage and other special requirements, parallel installation facilities can be used.