Is it allowed to install a stop valve in front of the safety valve?
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I would like to ask everyone: Is it allowed to install a stop valve in front of a safety valve? Which specification specifies this clearly?
Valves may also be installed in front of the safety valve, but they must be sealed with lead to remain in an open position.
A root valve is provided on the safety valve to keep it in an open position. Apply a lead seal
A regular gate valve will do; it’s not necessary to use a globe valve. Periodic calibration can be isolated.
There is nothing that is absolutely required or not; it depends on the practices of the patent holder. Many foreign patent holders enforce the rule that no manual valves may be installed at the inlet and outlet of safety valves.
I have reviewed the regulatory provisions mentioned on the fourth floor. Thank you, 4th floor!
In principle, it is not allowed, but it is done for the convenience of testing the safety valve. Root valves are added in many places from the design stage. Globe valves are more common, as stop valves serve to throttle the flow of the medium. That’s why few people install stop valves. Lead seals and no-movement signs are also added to the gate valve!
Also, the pressure drop before the safety valve should not be too large
If you can find the relevant design specifications, please upload them as soon as possible. So far I have only seen gate valves; I haven’t seen globe valves yet. Globe valves have a throttling mechanism for regulating flow, which makes them prone to clogging, while this problem should not occur with gate valves when they are fully open. It is recommended to use only gate valves.