Pressure Relief Valve Devices Frequency

[sonic1]

Hi Guys

I have been given the task to come up with a strategy for overhauling Relief Valve devices (PRV, TRV ect.) for a LNG facility. I have located and read the relevant regulations and guides in relations to setting the frequency period, however I am having some trouble applying it my situation

- this is a new facility - so I have no operational history
- regulations state that the max period is 5 years

So my question is, how do you break this down? Do you set a frequency period for each type of device or do you set the frequency period in regards to where it is located i.e LNG train, LNG storage ect.


Thanks!

 

[don1980]

The service fluid is the main factor affecting the service interval. Valves in corrosive, dirty, and fouling services need to be PM'ed more frequently than valves in clean non-corrosive services (such as LNG).

I don't think there are any prescriptive requirements that constrain this initial inspection interval decision. Different companies have different internal practices. Personally, I think it's appropriate to leverage experience from similar services, even if they're at a different facility. There's no right or wrong answer. Consult with maintenance and/or process safety personnel within the company, and make a decision that's consistent with corporate risk tolerance.

 

[sonic1]

Thank you for your reply, do you have any experience in regards to offshore rigs
do they send their relief valves onshore to be tested/overhauled or do they do it on the offshore rig?

 

[Duwe6]

I'd supprised if they overhaul PRV's on any rig. That requires a "VR" Code stamp. The most that most refinerys do is to "Pop Test" them. Good Pop = reinstall. Bad Pop = send it to a VR Shop. Reasonable presumption that this would be the most that would be done on a rig, considering that it might be 10% the size of a small refinery.