Cutting main drain line to relocate equipment

[JohnT]

I need to cut my main drain line between the valve and the pool to relocate my equipment inside the poolhouse I'm building. The point where I need to cut it is about 18" below the winter water level.

I'm sure I could cut the line and cram a rubber plug in there before the hole filled up, but how can I make a good solvent joint at the cut? Maybe I should have done it when the water was warm and I could have put a bucket over the drain and held it down with the pole.

I've heard that plumbers have a method of freezing the water in a line to allow repairs where the water can't be shut off. Will this work on an inch-and-a-half line?

[CanuckPool]

I have heard of plumbers using bread to plug up copper pipes with water in them so that they could solder on a new joint. The bread soaks up any residual water and then will eventually disintigrate and make its way out of the system... I am not sure with 1 1/2 pipe though, that would take one large french stick to plug that one.

[waste]

John, The only thing I can think of is to either lower the water below the pipe or 'take the dive' and plug the MD. I've experienced similar situations in the past and have yet to come up with another way to do it. It may be possible to temporarilly cover the drain with a sheet of vynal, etc. to slow the water down and use some 'blue' wet/ dry quick set pvc glue to make the final connection (plumb the line backwards from the pump and make the 'wet' connection the last one). Sorry, but that's the best I can come up with, though I'll let it percolate in the brainpan and ask my co-workers.

[mas985]

A plastic bag over the main drain might work. The suction/weight of the water should hold it down and seal it but there still might be a small amount of water that gets through. Use a large garbage bag and put it in position with a pole.

Of course if it doesn't work, you will have to drain the pool down below the level.

[MarkC]

A sandbag over the trashbag would probably really hold it down.

[sevver]

How about a rubber mission coupling? If the joints are together it should work out fine. I have used them probably a thousand times in my former career and they will pass a pressure test.

[JohnT]

How about a rubber mission coupling? If the joints are together it should work out fine. I have used them probably a thousand times in my former career and they will pass a pressure test.

I'm concerned about the amount of water coming in when I cut it. Can I put one on blind under a couple of feet of water?

[JohnT]

A sandbag over the trashbag would probably really hold it down.

I have a bucket with a very rounded edge large enough to cover the drain. I was thinking about putting that, with a sandbag on top, over the drain. Maybe a trashbag held down by a weighted bucket?

[JohnT]

I think I have a plan for this. I have some rubber feed pans like this
They are made of heavy rubber that is flexible and soft. If I can place one of these over the main drain and get some weight on it or hold it down with a pole, it should restrict enough water that the hole won't fill on me while I cut the old fittings and install the new.

I have fittings to work both compression and glued, depending on how things work out.

I also am in the process of modifying a standard expanding rubber plug by welding a piece of conduit on so I can slip a ball valve on after the plug is in place. I'll post a picture when I get it made and can try it out on a practice pipe.

Last piece of the puzzle is finding a reasonably priced full flow PVC ball valve to connect to the pipe and still allow me to withdraw the expanding plug after the valve is installed.

I'n not going to do the work until the pool is ready to open in the spring.

[hinejs]

I love challenges like this. I have often had to replace leaking ball valves below the water line at the equipment pad. I have everything at the ready. I use quick setting PVC solvent called Pool Tite. It hasnt failed me yet.