Compression helical spring
Compression helical spring
(OP)
Hi everyone!
I work with pressure vessels inspection and it includes pressure safety valves (PSV) calibration.
We have a new standard that recommend us to perform two tests on the springs that are part of those PSV. They are:
- Check if the spring axis is 90º +- 2º of the end plane;
- roll the spring over a plane surface and check if every coil is in contact with the surface for a complete tour, i.e. it must be a perfect cylinder.
The service is considered static. The spring is preloaded between 10% to 80% of the deflection range.
Those restrictions are promoting a rejection rate about 40% of the tested springs.
The question is: Are those tests too strict to this aplication?
Best Regards!!
Rafael Licursi
I work with pressure vessels inspection and it includes pressure safety valves (PSV) calibration.
We have a new standard that recommend us to perform two tests on the springs that are part of those PSV. They are:
- Check if the spring axis is 90º +- 2º of the end plane;
- roll the spring over a plane surface and check if every coil is in contact with the surface for a complete tour, i.e. it must be a perfect cylinder.
The service is considered static. The spring is preloaded between 10% to 80% of the deflection range.
Those restrictions are promoting a rejection rate about 40% of the tested springs.
The question is: Are those tests too strict to this aplication?
Best Regards!!
Rafael Licursi





RE: Compression helical spring
Be sure to inspect the new replacement springs to the same standard, and to be religious about rejecting the 'bad' ones. That may cause some readjustment of the standard.
Mike Halloran
Pembroke Pines, FL, USA
RE: Compression helical spring
RE: Compression helical spring
RE: Compression helical spring
I've never heard of a test like this done on PRV calibration and API-576 makes no reference to it.