Radiographic Test
Radiographic Test
(OP)
Hi guys,
How Can I know a pressure vessel need RT test or not and which level of RT? How can I know what is the joint efficiency of that?
If it was SS, or CS.
Thanks.
How Can I know a pressure vessel need RT test or not and which level of RT? How can I know what is the joint efficiency of that?
If it was SS, or CS.
Thanks.





RE: Radiographic Test
It depends on design of vessel, service of the vessel, load bearing of vessel, fluid pressurized in vessel.
Regards
Prasad
RE: Radiographic Test
Is it required any calculation? or is there some tables.
could you please guide me?
RE: Radiographic Test
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Radiographic Test
RE: Radiographic Test
RE: Radiographic Test
RE: Radiographic Test
Full RT is mandated by certain services and for over certain thicknesses, see UW-11. Extent of RT may also be mandated by customer specifications, for sour service for example.
Beyond that, the extent of RT is pretty much up to the designer, trading off the potential for reduced thickness (E = 1.0 for example) for increased inspection.
Note that joint efficiency based on RT is not applicable to corner joints, see Table UW-12.
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Radiographic Test
RE: Radiographic Test
Suggest you buy a copy of the code and read the relevant sections, assuming you are being paid to understand the implications of that code on your employer's work.
RE: Radiographic Test
Doesn't make it a good idea, necessarily :)
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Radiographic Test
RE: Radiographic Test
The extent and acceptability of spot is clear :See UW-52 SPOT EXAMINATION OF WELDED JOINTS
Regards
r6155
RE: Radiographic Test
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Radiographic Test
My comment about wanting to see " a spot, or two", isn't me stipulating a code requirement. As my previous post said, we have our own owner's/buyer's spec for subcontractor work which allows us to take random spot radiographs at our sole discretion- and cost- with the cost of repairs being on the fabricator. Fabricators know this and price accordingly- they typically don't bother going the 70% joint efficiency route on our jobs because of it. It puts people on alert that we're looking, which ups their game in terms of welding quality. On one early job, a colleague had a small (pipe-sized) vessel made for him by a local ASME shop, and had to cut off a large nozzle (a 600# weld neck flange, basically acting as a body flange) due to an alignment problem. The weld had a gap between root and cap passes that you could shove a piece of MIG wire into for a distance of several inches...Since then, we've looked on the use of the 70% joint efficiency with a very jaundiced eye. The threat of radiography keeps people honest, even if it's not relied upon for design as a code requirement.