Repairing a PVC pipe submerged under water

[plowhog]

My irrigation system has a drain that extends into and underwater in the pond. There is a gate valve near the end of that. Somewhere in the vicinity of that piping and valve there is a water leak. So I am losing irrigation water out of the system, which I don't want to have happen. I need to fix this *now* since once the first rain hits the pond level will rise a few feet. Right now the piping and valve are only submerged about 8 inches.

I have not yet figured out if the gate valve is threaded on, or if it is instead glued in place with the PVC pipe. Since it looks like a brass valve with plastic pipe, I am hoping there is a submerged male adapter on the plastic pipe end. But ... I am not positive the gate valve is the problem-- it could be a cracked pipe.

If I need to saw/glue PVC pipe, is there any way to do that if it is submerged? I could drain the pond down a foot but that is somewhat of an ordeal.

 

[Clint S]

Shark bite for PVC? That would be what I would try in this situation

 

[/pine]

if the pipe is cracked just use rubber w/clamp type couplings...no gluing required can be done in the wet...

Good Luck...

 

[plowhog]

I will look at that. The hard part is diagnosing what is leaking-- once I disturb anything it's instant mud and you can't see anything.

 

[MossRoad]

If its a drain line, it's got no pressure. Get a roll of Flex Seal tape and wrap it around the leak generously.

Also, if it's only 8" underwater, can it be lifted out of the water?

 

[RNeumann]

http://tchristy.com/product/red-hot-blue-glue/

I’ve had OK luck with this. They make repair couplings that I’ve also had OK luck with. The repair couplings provide a mechanical seal.

 

[cathy liebchen]

Hot Blue PVC glue works under water

 

[ch1ch2]

First thing is to find the leak.

 

[Travelover]

Can you lower the water level or slightly pressurize the pipe?

 

[plowhog]

If its a drain line, it's got no pressure. Get a roll of Flex Seal tape and wrap it around the leak generously.

Also, if it's only 8" underwater, can it be lifted out of the water?

Well, the pressure depends on the season. Right now that pipe is still full of water and has probably 42psi. It is a 1 1/2" pvc with a long down sloping underground run and then a short stub into the pond. So it won't budge.

Once I figure out the exact source of the leak and how I am going to fix it I can open other drain valves on other pipes much below this one to bleed off all the pressure and water. And I could block off any new water coming into the system. Then I could do a repair.