safety valve

[rika kose]

In the inspection round, our client got a comment on the natural gas safety valve.
Client has a Leser safety vavle https://www.leser.com/en/industries/lng-and-lpg/
But inspector said it must be this type https://www.bes.co.uk/natural-gas-lpg/natural-gas/valve/safety/.
because he has never seen a leser valve in the gas system. He didn't indicate what are the reasons.

I worked at LNG plant where a lot leser valves are used.

what are the differencese between the spring loaded type and the plate type. Is there any regulation?

 

[The Obturator]

They are completely different designs...

What is the applicable code/specification for the protected vessel?

A safety valve application is principally determined by the pressure and relief capacity it should pass in case of overpressure.

Those selections from BES seem to have very low pressures.

 

[Compositepro]

The two different valve types cover very different pressure ranges. LNG is high pressure. The other type valve are for low pressure used at point of consumption.

 

[LittleInch]

So inspector says it "must" be a particular vendor but doesn't say why??

Sounds like you need a different inspector. Or a complaint to whoever is employing him.

Agree those BES ones look like they are only valid for very low gas pressure in a domestic burner situation.

What "gas system " are these valves on (design pressure etc).

 

[rika kose]

the set pressrue is 250 mbar g protecting a burner.
The Leser valve has correct set pressure and relief capacity.

The inspector didn't specify the vendor but the type. He said that he had never seen the LESER valves in the gas industry.
LESER has to prove that those PSV's are suitable to the natural gas system. but he never specified which documents/codes, etc.
We discussed with the LESER vendor, but they don't know how to prove either.
If there is no prove, our client has to replace the PSV with the type he indicates.

 

[The Obturator]

250 mbar is low pressure, even for the Leser types - but it's not been indicated by you which Leser type/model no.

So Leser's local representative does not know - have they or you contacted Leser?

How can this inspector be rejecting the Leser valve types simply on the basis that he has never seen them in such a gas system?

Can my original question be answered which may provide the solution - What is the applicable code/specification for the protected vessel? If you don't know the answer to this, then your dilemma can't be resolved.

 

[georgeverghese]

In the 2nd link you posted, which the inspector recommends, there are 3 types of safety devices - valve 1, valve 2 and valve 3. Which one is he expecting to be at this location where the Leser valve is now ? We see that only valve 1 is a pressure relief valve. Note that a PRV is not a ASME / PED code compliant overpressure safety valve.

 

[The Obturator]

@georgeverghese 250mbar is below scope of ASME and PED.

If the OP can just advise to what code/standard/regulation etc., the vessel is built to, then we could answer better.

 

[LittleInch]

Leser simply need to write / supply a certificate of conformity stating that their valves meet the requirements of the data sheet for the relief valve ( 250mbar set point and the required flow rate and substance natural gas).

Then it is down to the inspector to state that he does not accept this or believe it, but supply the client / owner with this certificate and the cost of changing all of them to satisfy the personal preference of the inspector and let him decide which path he wants to take.