The pressure vessel automatically shuts off the feed valve when overpressure is detected; can a safety valve reduce the required discharge volume?
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This post was last edited by oceanlike on 2019-4-8 at 08:59. Based on GB150 standards, a container with an inlet mass flow rate of 400 kg/h should be equipped with a safety valve having a discharge capacity of 400 kg/h. However, the imported equipment in question is fitted only with a safety valve having a discharge capacity of slightly over 100 kg/h, as well as a feed valve with a SIL rating. Do European standards allow for reducing the discharge capacity of the container’s safety valve when the feed valve automatically shuts off due to overpressure? Please advise
As a supplementary note, it is a pressure switch with a SIL rating that is connected to the feed valve via wires; when the pressure switch triggers due to excessive pressure, the valve closes automatically
The safety valve should be used for venting first, followed by the closure of the automatic shut-off valve
This approach is correct; first, stop feeding material. The safety valve also operates at the same time; regarding the discharge capacity of the safety valve, there may be differences between foreign standards and domestic standards, and the design institute’s specifications shall prevail.
Thank you for the help. But there is concern that the Special Inspection Agency will not approve this approach, after all it differs from national standards.
Inspired by https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1680101&page=1#pid22287436, it is possible that since the stress source comes from outside the pressure vessel and can be reliably controlled, pressure switches and shut-off valves are used as reliable control devices; therefore, a very small amount of leakage is permitted.
It depends on the risk level of medium leakage; for specific guidance, refer to the combined assessment using Hazop and LOPA