Selection of the airtightness test pressure for pipelines equipped with rupture disc safety valves
Thread Content
It’s once again a question regarding the selection of pressure for air-tightness testing. Although there are already many posts on the forum, they still haven’t resolved my doubts, so I’m posting here to ask for help: Since PP systems may contain various types of powders and particles, a burst disc is usually installed in series before the safety valve. The setting pressure for this burst disc is the design pressure. So, what should be the appropriate test pressure during pipeline air-tightness testing? When selected as the set pressure, the burst disc will inevitably rupture. If it is set at 1.05 times the operating pressure, there is still the issue of the burst tolerance for the rupture disc; for example, the tolerance might be ±5%. If the design pressure is around 1.1 times the operating pressure, then the airtightness test pressure will be very close to the minimum burst pressure of the rupture disc, resulting in a high likelihood of the disc breaking. Therefore, for pipelines equipped with rupture disc safety valves in series, what should be the appropriate value for the airtightness test pressure? Should the limit imposed by the minimum burst pressure of the rupture disc also be taken into consideration? Is it sufficient to achieve airtightness only up to the maximum operating pressure? I hope everyone can share their experience and suggestions. Thank you!
It’s double insurance! Remove the burst disc, first test the safety valve, then reinstall the burst disc and test it
Blowout valves, safety valves – those that are involved in pressure testing? No need to be isolated? After reset, a leak test is performed.
What should the airtight pressure be after installing the blast disc?
Well, it’s to determine the leakage test pressure with the burst disc in place
Install blind flanges, and determine the test pressure in accordance with the specifications···············
It’s not a pressure test… it’s a high-pressure airtightness and leakage test
This post was last edited by waaabc on 2016-4-29 at 11:02. For a leak-tightness test of a safety attachment that is fully equipped, the test pressure must be equal to the design pressure; otherwise, the purpose of the test is lost. The poster needs to determine a value representing the maximum allowable operating pressure of the system, namely MAWP; this value is generally higher than the design pressure. During the test, you just need to set the bursting pressure of the rupture disc to this value ； After the test, replace it with the burst disc at the designed pressure.
Neither burst discs nor safety valves are involved in the pressure testing
Thank you for the discussion, but does this mean we need to purchase two different types of rupture disks? The set pressure of the burst disc is determined during manufacturing and should not be able to be changed.
Well, it doesn’t participate in hydrostatic or pneumatic tests, but burst discs and safety valves need to be installed during the airtightness test