Trouble with gate-valve

I'm trying to install a new sediment filter to replace the crappy mesh-screen filter I currently have. I just found out that the gate valve immediately following my pressure tank (I have a well) will not close completely. The net result is that I can only reduce my water to a trickle instead of shutting it dry.

The only other way I can stop the flow of water to my house is to shut off the well pump, and drain my pressure tank. Which is the ultimate fix, since then I could replace my broken gate valve. The problem is this, my pressure tank has a bunch of sediment in the bottom, and when it empties out, it makes a mess. Secondly, when I shut the pump down, I affect the neighbor who shares it.

What I would like to do is quickly cut the PVC pipe and quickly install a new shutoff valve (after the gate valve) to stop the flow. Then I can leisurely put my new filter in place.

Can someone recommend a method for QUICKLY installing a new shutoff valve. I have a solvent-style valve now. Is it possible to get this valve installed while the pipe is wet since water will be flowing through as I try to apply the cement?

Any recommendations here are greatly appreciated.

-Nick

Nick, it's been my experience that a patch job "just until I have time to do it right" ends up being almost permanent. You have a rather nasty job to do, but it needs to be done. If this water is shared with a neighbor, why not get him to help. Get the parts you need ready, have both houses drawn some water of immediate use, and do the job right and be done with it. BTW, replace that gate valve with a ball valve. I know of no PVC solvent that will work with water flowing, but there may be some that I haven't encountered, when I work with PVC, I just get the "regular stuff" that I've always used. At least PVC pipes don't have to be drained as they would if you were soldering copper. That's my not-to-humble recommendation.

One problem that you will have is that it takes several hours for PVC cement to get strong enough to hold pressure. Since the gate valve is probably a threaded valve, you may want to get a threaded PVC ball valve. I have found them at HD.

With pressure piping I always use primer as well as cement on the PVC joints, on both male and female parts, give it a 1/4 turn while seating the male part all the way to the stop, and hold it in place for about 30 seconds.

If you can't get the threaded valve, then maybe you can adapt the valve to threads before you tear things apart.

Be sure you don't get DWV fittings. The small stuff at HD is Schedule 40 which is probably OK.

Yep. Based on the comments here I think I'm going to proceed with flushing the sediment out of my pressure tank, and replacing the failing gate valve. At the other big box hardware store all I found was solvent fittings in PVC style. All the stuff I picked up was 1" schedule 40.

Right now the gate valve on there is cast with PVC screwed into it. Is there anything special I need to know about making this type of connection? I assume that some teflon tape will make the seal. I guess ideally I'd like to replace the failing gate valve with a screw in PVC ball valve. Then add additional PVC ball valves before and after my new sediment filter.

This is starting to turn into a real project.

I really appreciate the input you guys have offered.

-Nick

Don't go too crazy when you use threaded PVC fittings. I had one crack and burst, causing a nasty flood. I watched the pro plumber install this (part of a water conditioning system) and he really cranked down on a pair of 18" wrenches, saying "my joints don't leak."

With PVC I would use a solvent weld ball valve. It will only take about 1/2 hr. max to be strong enough to hold up to pressure. Threaded PVC can split the female fitting or develope a leak at the threads. If you want the ability to disconnect the line install a PVC solvent weld union somewhere. Turn the well off and drain everything down while doing the repair so water is not running.