Swap shut off valves?

[mmcgovern]

I am thinking ahead to when I try to close my pool by myself for the first time in a few weeks. The picture below shows the three pipes coming from my two skimmers and the main drain. I need to air lock the main drain but can blow all the water out of the skimmer lines. The far left valve is for the main drain but the shut off lets water through when it's closed. The other two for the skimmers work as intended...of course . Since the main drain valve is the one I need the air lock on, can I swap the innards of one of the other shut off valves with the not quite functioning one in the main drain instead of cutting pipe?

 

[X-PertPool]

Undo the unions of all 3 valves and remove the top plumbing assembly away from the valves coming out of the ground. Simply blow the main drain directly through the valve and use a rubber compression plug to seal the maindrain. Naturally you have to do it fast but if you try it a few times in a row you will get good at blowing and quickly jamming a rubber plug into the hole. Once the main drain is plugged put a solution of dish soap and water on the plug and look for bubbles as sometimes the stems leak on those plugs or it may even leak around the edge. If you don't see any bubbles secure the rubber plug from popping out with duct tape or electrical tape to prevent the plug from slowly popping out of the winter.

 

[bof]

Hi
You could get a plastic bag of sand and cover the main drain I know this works.

 

[mmcgovern]

Thanks for the ideas! I thought about using a plug on the shut off valve but I'm not sure if the guts of the valve will interfere with the plug. I suppose the only way to find out is to do it and see what happens.

 

[X-PertPool]

It won't interfere you just may need to take the guts out first. it will probably be a #8 plug that goes deep into the body of the valve.

 

[ps0303]

Those valves are garbage. For the future, I would consider replacing them with some never lube valves.

 

[mmcgovern]

Well, I've decided to use a combination of everyone's advice. I am going to remove the upper portion of the plumbing, cut out the bad shut off valve and install a compression plug on the stub end. The other two valves go to skimmers that I can get all the water out of so I'm not worried about the upper plumbing....not to mention the shut off valves for those actually work.
On a side note, as far as I can tell, the shut off valves are above the water line. When I remove the upper plumbing, water runs up and out of the main drain pipe. Not a ton, but it just keeps streaming out until I put the pmumbing back together. The two skimmer lines don't do that. What am I missing? Does this have something to do with a hydrostatic relief valve I may, or may not have?