Is it acceptable to use a safety valve with a reduced set pressure?
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There is a spare safety valve, with an original set pressure of 0.8 MPa; the medium used is cooling water. Now, I want to adjust its set pressure to 0.3 MPa so that it can be used in nitrogen pipelines. Is this possible? Are there any relevant standard specifications?
This post was last edited by ylb913 on 2016-2-27 at 13:25; it should be set within the pressure range of the spring. The pressure change is too large; it definitely exceeds the set pressure range of the spring, making it impossible to achieve a proper setting.
Are there any relevant standards and guidelines? I want to learn *how to do it*, expert.
Have professional agencies handle it; the relevant departments also need to keep a record of it
The set pressure difference is too large; the internal elastic components need to be replaced.
Just ask the Special Inspection Institute; you’ll find out. Even for the calibration of safety valves, they are the ones who need to carry out that task
When the medium changes, it is advisable to consult the design institute or the manufacturer to see if a replacement is possible. After all, they will consider whether this type of safety valve meets the requirements for use in nitrogen pipelines, as well as whether its pressure can be adjusted.
Medium change: liquid-to-gas; the molecular weight and leakage rate need to be recalculated, as the elastic range varies depending on the spring steel grade
The key is whether the safety discharge capacity is sufficient