Issue of multiple safety valves sharing one interface
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Several standards require that if several safety valves share one inlet pipe, the cross-sectional area of this inlet pipe must be no smaller than the sum of the inlet cross-sectional areas of these safety valves. Is it true that, with this type of connection, the main pipe must be thicker than the branch pipes? In the case of safety valves that operate in one at a time, with one valve in use during normal operation while the other inlet and outlet manual valves are closed as backups, is such a setup really necessary?
I don’t know; I’m here to ask for advice.
I remember a tutorial saying that it wasn’t meant to be that way, right?
Please explain, I’d appreciate it!
This post was last edited by Zhang Junli on 2021-12-8 at 08:37. If a safety valve with a DN200 size is required for the design, it is necessary to ensure that both the safety valve and the connecting pipes have a diameter of at least DN200. If four DN100 safety valves are used, then the corresponding connecting pipes must also be DN100 in size, and all setting pressures must not exceed the requirements specified in the design. If it is for one in use and one as a backup, then both must be DN200.
You can’t use two safety valves connected to the same pipe, right?
A DN200 is not equivalent to two DN100s; the flow area difference is significant. The flow area of a DN200 is equal to the sum of the flow areas of 4 DN100s. Therefore, two DN100 pipes cannot replace one DN200 pipe.
Thank you for the correction; it was me who was wrong. One DN200 should be replaced with 4 DN100s
If two safety valves, one in use and one as a backup, share the same interface, does the cross-sectional area of that interface need to be equal to the sum of the inlet cross-sectional areas of the two safety valves?