I need some creative ideas on how to repair/modify an 8ft diameter butterfly valve that is out of round (probably that way at initial construction). Valve isolates cooling water to section of power plant condenser. Leakage is too great to allow condenser maintenance downstream. Repair/modification would have to be done in situ. Any ideas or people to talk to.
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Out of Round 8ft diameter butterfly valve 1
- Thread starter dmk417
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MikeHalloran
Mechanical
I.e., without shutting down everything, right? Yikes.
Maybe you can reduce the flow without repairing the valve.. Can you find a way to insert and inflate a big-ass tractor inner tube or bladder upstream of the almost- closed butterfly?
... probably violates all kinds of safety rules.
Mike Halloran
Pembroke Pines, FL, USA
Maybe you can reduce the flow without repairing the valve.. Can you find a way to insert and inflate a big-ass tractor inner tube or bladder upstream of the almost- closed butterfly?
... probably violates all kinds of safety rules.
Mike Halloran
Pembroke Pines, FL, USA
What do you mean out of round? Are you sure it is not the design pivot excentricity in the valve to make it seat better against the valve seat when closed sagainst the upstream water pressure? Maybe it is just the valve seat that is out of place. Or maybe the valve is installed backwards (flow direction opposite valve design flow direction).
Are there other upstream valves that you can open to divert or reduce the flow to the bad valve to the point that repair work can be performed.
Are there other upstream valves that you can open to divert or reduce the flow to the bad valve to the point that repair work can be performed.
Do you have a picture of an 8' dia butterfly? That has to be a site to see.
If you worried about repairing something downstream, there are companies out there that can freeze water inside the pipe so you can do repairs and maybe add other isolation valves so you don't have to do this again.
Do a search on here I think it was discussed not to long ago. I am sure it isn't going to be cheap though.
Zuccus
If you worried about repairing something downstream, there are companies out there that can freeze water inside the pipe so you can do repairs and maybe add other isolation valves so you don't have to do this again.
Do a search on here I think it was discussed not to long ago. I am sure it isn't going to be cheap though.
Zuccus
STYMIEDPIPER
Mechanical
Something silmilar occurred twenty some years ago, hence details are vague
The valve was repaired at make-shift repair shack/lean-to at the site.
The valve fabricator had bolt holes at one flange end filled with weld filler metal and holes were redrilled thru undisturbed steel to suit field bolt-up requirements.
I do not recall the intended service of the valve but it must of been very low pressure system for client to buy off on repair. At very large diameter the numbrer of bolt holes can be overwhelmiing
The valve was repaired at make-shift repair shack/lean-to at the site.
The valve fabricator had bolt holes at one flange end filled with weld filler metal and holes were redrilled thru undisturbed steel to suit field bolt-up requirements.
I do not recall the intended service of the valve but it must of been very low pressure system for client to buy off on repair. At very large diameter the numbrer of bolt holes can be overwhelmiing
As noted, safety is your biggest problem. I can't imagine anyone who is going to get inside the condenser to work on the valve with even just static head against the valve, even in scuba gear! Any repair is most likely going to require that the disc is partially open, away from the seat. Once you have the pressure off and water drained, there are any number of ways to force the valve body back to round, but replacement may be quicker and cheaper, and ultimately more reliable.
The mechanic's friend, Bar's Leaks:
not sure if comes in tank car packaging.
not sure if comes in tank car packaging.
I would give these people a call. I've used their products though not in your size.
I haven't checked lately but there may be places you can rent a plug. Also there are several other people that make large pipe plugs with inflateable seals.
I haven't checked lately but there may be places you can rent a plug. Also there are several other people that make large pipe plugs with inflateable seals.
How has the 'unround condition' been verified? If tested droptight before installation, the 'unround' condition will have to have been caused by mechanical forces inside (water hammer, higher pressure than allowed) or outside (unproper fastening or weight from unsupported parts of pipeline construction) over time. May occur, but more unlikely than sealing damage or sealing hardening over time.
In my opinion: very difficult in any case to repair inline. Shut-down and replacement recommended.
In my opinion: very difficult in any case to repair inline. Shut-down and replacement recommended.
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