Can one of the safety valves, the one in use and the one as a backup, be closed?
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Dear sea friends, I have a question: there are 2 safety valves on the steam pipes on site, and both are within their valid calibration period. Can one of these valves be closed? Use only one. Are there any standard specifications that can be consulted? Thank you
Are the set pressure values of these two safety valves the same? It’s likely that the design documents can no longer be found either.
I checked the calibration label; the set pressure is the same
1. Do not rely on the set pressure of the valves on site; instead, refer to the pipeline design drawings and safety discharge calculations. Avoid on-site installation errors that might lead you to think there is one in use and one as a spare. 2. Generally, the two valves are the working valve and the control valve; check the design documents. To avoid misunderstandings, if it can’t be released at that time, it will explode. 3. Why does this valve’s position seem so awkward the more I look at it? Is it in the highest position? And being this close is so uncomfortable.
It should be fine to turn on both of them on-site, right? Can we turn it off?
If it is confirmed to be one active and one standby, one of them can be turned off. It’s best to take a look at the original pipeline design drawings; it’s possible that the design at that time was for a 2-way setup
Looking at the design drawings, the presence of two safety valves in the same location suggests a design for high flow rates; both valves need to be opened in order to meet the required flow volume. In case of a jump, if you close one, there won’t be enough time to release the pressure.
I agree with the view from the seventh floor, and what’s your intention behind turning one off? Whether it’s one in use and one as a backup or considering overpressure relief, must it be in use? ? ? Why do people think it’s possible to shut one down? If it’s possible to shut one down, why not design just one?
Looking at the PID diagram, it shows one normally open and one normally closed device. Is it okay to close just one of them usually?
Turn it on and off according to the PID diagram, and seal it with a lead seal. It is recommended to review the safety valve calculations again for extra safety.