ASME BPVC Lethal Service requirements
ASME BPVC Lethal Service requirements
(OP)
Hello everyone,
I have a pressure vessel designed to the ASME code and stamped for lethal service (L-stamp) it has been operating for over two decades with no real problems but during a recent shutdown and inspection it was discovered that an inlet/outlet pipe was not attached with a full penetration weld but with a single sided fillet weld on the outside. Obvious this is a huge code violation because all welds in a lethal service system needs to be full penetration to reduce the risk of a weld failing and releasing lethal chemicals into the air/environment and possibly causing serious harm/death to personnel.
My question is if we want to deactivate the system should we cross out (score out) the L-stamp to signify that this vessel is no longer rated for lethal service (because it was never correctly build).
Also, if we want to continue using this vessel after fixing the code violation (Via cutting out the fillet welds and making them full penetration, and going through the process of R-stamping it) is it alright to leave the original L-stamp on the nameplate?
Thank you for your insight,
Tyler
I have a pressure vessel designed to the ASME code and stamped for lethal service (L-stamp) it has been operating for over two decades with no real problems but during a recent shutdown and inspection it was discovered that an inlet/outlet pipe was not attached with a full penetration weld but with a single sided fillet weld on the outside. Obvious this is a huge code violation because all welds in a lethal service system needs to be full penetration to reduce the risk of a weld failing and releasing lethal chemicals into the air/environment and possibly causing serious harm/death to personnel.
My question is if we want to deactivate the system should we cross out (score out) the L-stamp to signify that this vessel is no longer rated for lethal service (because it was never correctly build).
Also, if we want to continue using this vessel after fixing the code violation (Via cutting out the fillet welds and making them full penetration, and going through the process of R-stamping it) is it alright to leave the original L-stamp on the nameplate?
Thank you for your insight,
Tyler





RE: ASME BPVC Lethal Service requirements
Or, was the vessel constructed in accordance with the design drawings ?
What about the U-1 data report ? Is the sheet signed by an authorized inspector ?
MJCronin
Sr. Process Engineer
RE: ASME BPVC Lethal Service requirements
My reasoning on why it didn't get welded correctly is because there are components inside the vessel that would make it almost impossible to weld correctly and that the welder was just lazy. We have a few vessels with this problem and you can see him "attempting" the correct weld on one of the vessels then giving up and doing only external fillet welds on the rest.
The vessel was inspected and signed off per the U-1 data report.
RE: ASME BPVC Lethal Service requirements
2) Contact an lawyer
Regards
r6155
RE: ASME BPVC Lethal Service requirements
RE: ASME BPVC Lethal Service requirements
RE: ASME BPVC Lethal Service requirements
RE: ASME BPVC Lethal Service requirements
Regards
r6155
RE: ASME BPVC Lethal Service requirements
RE: ASME BPVC Lethal Service requirements
As I thought more about the above.... was this inlet/outlet pipe added after the vessel was constructed/stamped and placed in-service, especially for a 20 year period? I would think that during original fabrication, the inlet/outlet pipe would have been done without vessel internals. I suppose anything is possible but it does seem rather odd to me.
RE: ASME BPVC Lethal Service requirements
ASME rules are hard and fast.
Unlike house plans, pressure vessel drawings and U-1 reports are legal documents and not design suggestions ..... especially for vessels stamped for LETHAL SERVICE.
If modifications were made after the vessel was in service, then the Repair Stamp rules apply.
We are dealing with serious safety issues here ..... IMHO, incomplete welds on a vessel are like putting a bullet in the chamber of a gun
MJCronin
Sr. Process Engineer