Leaking irrigation valve

In front of our house there are set of 3 irrigation valves with the same type of brass body. All of these leak, no two in exactly the same way. They look more or less like this Champion CL466-100-C-2T, but are nearly 60 years old:



It is hard to get a picture from the side on the actual units because there is a rose bush on one side and another big solid bush on the other.

The inlet side starts with vertical steel pipe coming out of the ground, then some sort of adapter that screws into the bottom. The outlet side has some sort of PVC adapter glued onto a PVC pipe that goes into the ground, and the top of that adapter is held to the body with the nut.

Two of them have had the flying saucer like valve part replaced with a plastic controller.

The two on the left as I face them were both leaking from the top of the anti-siphon. Bought 3 rebuild kits and unscrewed the "lids". Unfortunately the saucer on top of one prevented the lid from coming all the way off. The two which were leaking both had the thin gasket material to seal the lid, the one which wasn't leaking had a big black washer. Since the rubber seems to have held up better than the gasket, and there was a washer of that size in the kit, the two of them where the lid would come all the way off were rebuilt with the rubber washer. Murphy dictates that one of the two blown gaskets was on the unit where the lid wouldn't come off. I didn't want to shut off the water, so for now that one was closed up as best as possible and screwed back together. Of course, it leaks, a lot.

With the anti-siphon fixed on the one on the middle I see now that it is also leaking from both the top and the bottom of the nut visible in the picture at the outlet. I'm guessing that there is a washer or gasket of some sort between the top of the adapter and the bottom of the brass body.

I don't see how I'm going to be able to replace that though without tearing pretty much everything out. If the nut is unscrewed that should provide access to the side of the junction, but that may not be enough to repair the washer/gasket. If the adapter goes flush against the brass body it might be possible to pry the unit up enough to scrape out the washer/gasket and replace it. If either the body or the adapter extends through the washer/gasket though, that won't work. (Also the other side is steel, it isn't going to move much.)

What is the usual way to go about this? I'm thinking maybe cut the PVC outlet pipe (it is either 3/4 or 1", I have not measured) in two places, below the nut. Remove that segment. Loosen the nut then drop out the adapter with the remaining stub of pipe. Reassemble with a similar adapter, bit of pipe, and some sort of slip junction to the bit of outlet pipe sticking out of the ground?

Or is there a way to seal around that nut with some sort of magic tape? It is only under pressure 10-20 minutes a week, and if it does start to leak, it won't be any worse than what we have now.

Finally, the two replacement valves both leak from where they are screwed into the brass body. I'm hoping that is because they were put on without any teflon tape or dope (I don't see any), so that wrapping/coating them and then screwing them back in will resolve that. The original flying saucer valve doesn't leak, but it has to come off anyway to rebuild that antisiphon, so it might when it goes back together.

I had a similar issue years ago. It took all day to find the correct size rebuild kits, and seemed to always leak. I finally cut out all the brass valves and replaced them with plastic Rainbird valves, for 1/5th the price. Surprisingly, they last just as long and if I ever need to replace them, I cut them out, and reglue new ones in for about $14.

Here are some pictures of these valves, taken by my intrepid son who stuck his hand through the rose bush to get them.

In the first picture you can see that my initial description wasn't quite right. There is no adapter between the steel pipe and the brass inlet, that pipe is screwed right into the brass. At the outlet there is nut, then what looks like a brass adapter (B), then a PVC adapter (A). Adapter A is certainly glued to the pipe below it. One of these leaks water out of both sides of the nut as shown by the arrows. The nut and adapter B are visible in the picture in the first post. The strange angle on the bottom of A is a distortion from the camera angle, it is square across the bottom.

If the nut is loosened up, what are the odds that adapter B can be screwed down the threads of adapter A to provide enough clearance to change the rubber washer which is supposed to be located on top of B? Assuming that works, when it is screwed back up again, and the nut tightened, even if the leak under the nut fixed, will it now leak between A and B? This is very old PVC, exposed to heat and sun for a long time, so it may be quite brittle.

I really don't want to mess with that back steel pipe. In theory if the outlet was unscrewed the entire assembly could be unscrewed from the steel pipe. But an old steel pipe like that could just snap off instead. There is rust visible on the threads and those bubbles under the crust of calcium deposits, near the bottom edge of the picture, are probably rust too.

In the second picture the arrow indicates where there is a leak between the valve and the base. I'm hoping that if the valve is unscrewed, its threads wrapped in teflon tape, and it is screwed back in, that it will stop leaking. Apparently using pipe dope is a no no in this sort of system since it is said to work its way into the pipe eventually and jam up sprinkler heads.

So yesterday I had another go at it.

For the one which was leaking at the nut. The nut was loosened and screwed all the way down. Underneath one finds a black rubber washer between the bottom of the brass body and the top of the brass adapter (which is at the top of the outlet pipe.) Poked at it a bit with a screw driver and it still seemed to be flexible. So the nut was run back up, cinched down very tight, and it seems not to leak now. Time will tell how that will hold up. I hope it does because the PVC beneath it is quite thick and isn't going to be easy to bend down enough to clear the bottom of the brass body unless many feet of the outlet pipe is excavated.

Then tried to fix the leak at the bottom of the green Orbit valve. See the picture below - the leak was at the red arrow. Unscrewed it and pulled it out. Removed as much of the deposited crud on top of the brass body as possible by gently scraping it with a pretty dull flat bladed screwdriver. (Trying not to scratch that surface.) There is a round cross section rubber O ring at the top of the brass threads on the valve. Removed that and put on a flat rubber washer. Screwed it back down - and the top didn't leak but the bottom plunger also didn't seal, the sound of water gurgling in it was audible and water began to dribble out of the lowest sprinkler heads. Cleaned all the deposits off the O ring, found that it was still flexible, and put it back on. Taped the threads, being careful to keep the tape only on the threads and not extending more than a millimeter or so inwards to where the water flows. Reassembled. The plunger sealed very very poorly and a lot of water came out of the sprinklers.

Took it all apart again. It turns out that there is a black plastic nut of sorts right under the brass threads, indicated by the green arrow in the picture. If that loosens up the brass threaded part can move up and down with respect to the plastic valve body. It was able to move about a centimeter. Tightened it up as best as I could by hand (there are some slots in it but one would need a special tool to fit, kind of like the split tool used to tighten brass sprinkler heads.) Retaped it, reinstalled it, and ...

The valve worked as a valve again, but there was still water oozing out in the same place. (Previously it sprayed out from one location.) So still not fixed. At that point I left it for another day, since it was getting dark and I was tired of kneeling in what was now mud. It was leaking, but less than before.

Somehow I need to seal the bottom of that brass flange which is just above the red arrow better to the brass body. I don't think those really thin spacers which are normally used to do this for the original brass valve are going to work because neither of those surfaces is very smooth, due to hard water deposits. Perhaps if I clean them both really well with some vinegar. Alternatively, a much thinner rubber washer might do the trick and not cause the plunger at the bottom to leak.

pasadena_commut said:

The valve worked as a valve again, but there was still water oozing out in the same place. (Previously it sprayed out from one location.) So still not fixed. At that point I left it for another day, since it was getting dark and I was tired of kneeling in what was now mud. It was leaking, but less than before.

Somehow I need to seal the bottom of that brass flange which is just above the red arrow better to the brass body.

Click to expand...

Oddly this stopped leaking all by itself. (No I won't be surprised if it starts again.)

Funny thing though, even with none of the valves leaking there was still an immense puddle next to them after the sprinklers ran. Turned out one of the bushes had grown out enough to block about 1/3 of one sprinkler head's output. That was dripping down the bush and draining back towards the valves. I had originally thought all of that water was coming from the leaking valves.