Grayloc sealing surface

[CWEng]

Is there any way to rework or remachine the sealing surface of a damaged grayloc fitting (there is a ding on the inside corner), or is the only way to fix it to cut off and weld on a new one?

 

[marty007]

I'd imagine you could do a weld-buildup / remachine with the right qualified people.

I think you'd want to confirm roundness after the weld-buildup, and ensure a certain surface finish after machining.

First thing I'd do though is contact Grayloc and ask. Just be aware that they may try to sell you a new part...

 

[CWEng]

I didn't know if just re-machining would work because the clamps seem to depend on a specific flange thickness, which would be reduced. I know a weld buildup would work if we can re-machine it. It's in the field, attached to a vessel, so I'm not sure what can be used to remachine. It seems like the ID would need some machining too since it's on the corner, and any weld repair would have to go at least partly into the ID. My impression of standard portable flange facing machines is that they would only do the face, not the radius or ID.

 

[ricklts]

CWEng,
There should be a small amount of rework material available, but that would depend on the origianl thickness of the hub face to 25° backface (clamp engagement) area. Depending on material/costs/circumstances, you may want to contact one of the field service companies, they pretty much all do such field work and have tools set up specifically for grayloc and rtj joints. I work for a competitor, so I can't just say call me.

Is the joint leaking? Can you see the 'seal point' mark on the seat? If your ding does not impede or cross that line, you might be able to just hand buff the ding out. If it crosses that line, then your defect is a potential leak path and needs to be addressed.

 

[CWEng]

Thanks Ricklts. The damaged surface appears to deform the flat surface of the "flange", and slightly into the sealing surface on the ID. I'm not completely sure what you mean by "seal point mark". I've only seen pictures of the damage, and it is not installed yet, so hasn't had a chance to leak.

 

[ricklts]

CWEng,
If the damage is on the flat face of the hub, and does create a raised or depressed area further than the first 1/8" or so of the seal surface, you could probably get the supplier to inspect and recommend/comment on the need for rework. Take a look at the intended seal ring - what I refer to as 'the seal point' normally is within the last 1/3 of the length of lip of the seal ring. Shallower/outside of that, minor surface defects do not normally have an impact on the sealing of the connection. If you can figure out how to send me a copy of the picture, I'll do my best to offer my two cents worth.