PSV testing as received condition 2

[Nasim12345]

Dears
I am working in Refinery & petrochemical company. As soon as we received any psv from any service(Like Hydrocarbon, Phenol, Cumene, Sour gas, Crude oil etc..)in the PSV shop for testing & calibration, our initial step in the shop is visual inspection as received condition. If there is no deposit & no foreign material observed in the PSV outlet/inlet, we will clean the psv and test it.

In API, it is mentioned that, we must conduct "As received test". If we conduct the test "As received condition", whatever products(even very small amount)available on the psv outlet, it will be sprayed on the testing work shop environment when the PSV open. To avoid such situation, we are cleaning all PSVs prior to "As received test". Once the cleaning completed then only we are conducting initial test.

Such practice is acceptable or not? One auditor made a comment that, prior to clean any psv, it must be tested as "received condition", means prior to clean the psv. If crude oil service psv test in the liquid test stand, crude oil particles available on the psv outlet will splashed to the test stand glass & it will go the water test stand water storage tank. Likewise, different service pzvs product deposit will go to the water storage tank and a lot of deposit will be deposited on the tank and it may come in between the seat area, during psv opening & seat may damage.

Pls advise me, psv cleaning is acceptable prior to initial test as received condition. If yes, pls share me the procedure paragraph number

 

[The Obturator]

I think the API statement of 'as received' condition is meant for newly delivered PRV's and not ones that had been in service. Please advise the API standard you are referring to/

It is necessary to decontaminate a PRV that has been in service, before you attempt to test it. This should be a documented exercise in your HSE procedures. The process of decontamination does not mean to thoroughly clean the valve, but rid it of noxious and potential poisonous fluids. The purpose of this test is to determine whether the PRV would open at its predetermined set pressure after being installed. This allows the user to build up a record of the PRV's reliability and service record.

Experienced operators should leak test the PRV first (at 90% set pressure per API-527), before set pressure testing as opening the seats could potentially leave fluid debris on the seats increasing leakage - the leakage test would be for information only as API-527 limits would not be expected to be met anymore.

API-576 Provides good guidance for inspection of PRD's in service, and mentions the facts I stated above. You might also want to review the comprehensive recommendations in the National Board Inspection Code NB-23 - Part 4 - Pressure Relief Devices which provides detailed instruction for all PRV testing during and after installation.



*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[Nasim12345]

We are following all international standards like API 520; API 527; API 576 etc..

 

[The Obturator]

Regarding your original 'as received' query. API-576 (2017) Section 6.2.9 explains the steps to take for as received by maintenance shop testing.

*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[Nasim12345]

Thanks for your feedback. It is mentioned in the procedure that we need to conduct the initial test "as received condition". However, practically it is not possible. As soon as we received the PSV in our shop, first job is clean the inlet/outlet area & clean psv external body. After cleaning, then only we are conducting the initial test. If not, whatever products(even very small amount), or duct particles available on the psv inlet/outlet, it will sprayed in the shop environment & it is dangerous to the personnel whoever is present near to the testing area.

Pls note that, if there is any abnormal deposit found on the psv outlet, we will skip the initial testing(otherwise it may damage the seat because of product deposit on the inlet/outlet area). Such PSVs will go for direct overhaul, without initial testing.. It is mentioned in API procedure & our company procedure. No issue for such scenario.

In our plant, PSVs are installed in H2s, Sour gas, Cumene, Phenol, Hydrogen, Nitrogen, Crude oil, Naptha, Acid service...(i mentioned very few service only). More than 7500 PSVs are available in our plant.

I don't know, how i can explain to the External Auditor for this finding. He noticed that, we are not following the API standards & our company procedure. His point is prior to test it(As received condition), don't clean the PSV. But for us, it is not acceptable, because of above mentioned issue.

Can you pls advise me how i can explain to the auditor & how i can close this Non-conformance report.

 

[The Obturator]

You need to read API-576 (2017) paragraph 6.2.9 in more depth,, in particular, the following statement within paragraph 6.2.9.1.

"...pop testing in the as-received condition for valves in acid/caustic/toxic services can be accomplished by utilizing a pop test stand built on site in the area where the valve is installed, or by contracting with a service supplier that has a portable test stand that can be brought to site...."

If you cannot follow this recommendation, then you should waive the 'as received' test as per the caution at the end of paragraph 6.2.9.1. - You are then following any reasonable Health and Safety procedures that may be laid down.

Your auditor should be well aware of the risk to health & safety and further have access to the contaminated fluids Safety Data Sheet, giving him ample caution to agree the waiver of such testing of contaminated valves. Health and Safety should be above such testing requirements. It's not as if the valves are going back into service. Your maintenance records should also state that no testing was carried ot and consider more frequent inspection/overhaul.

*** Per ISO-4126, the generic term 'Safety Valve' is used regardless of application or design ***

*** 'Pressure-relief Valve' is the equivalent ASME/API term ***

 

[Nasim12345]

Thanks Obturator for your valuable advise..