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

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

For the spring safety valve used for corrosive medium, the 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 gas spring 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.