I need to install a new prv in my house. I've put a gauge on a hose bib outside the garage and turned the adjusting screw clockwise but no change on the gauge. It stays at 90 psi, drops to 80 or so when running water. I am bleeding off pressure at another bib after each adjustment. So presuming I've done all I can I guess its time for a new one. The prv is threaded onto copper male adapter and has a union on the other end. Having the union is fine but I still have to spin the valve to get off the other fitting. I don't trust my sweating skills to try this the right way. So my question, finally, is can I unscrew the bonnet (cone shaped part of valve) off while taking off/putting on the new one without damaging the valve. It is too close to the wall to spin without taking it apart. This is a Watts 3/4 inch aub and is 5 1/4 inches end to end. If I can't find one with same dimension then its plan B anyway.
Thanks!

 

Here's a picture of the valve up close against the wall.

 

I don't know how to do the job, but I think this may be what is on their now. It indicates as you say: the AUB end to end for 3/4 would be 5 1/4 inches.

http://media.wattswater.com/ES-LF25AUB.pdf

I bet the pros will be along soon.

just thinking, looks like you can get that with a double union. It seems to me you would be having
an easy time if the double union had been installed - I think,lol. But i guess that doesn't help you
now.

 

Try turning the adjusting screw counter-clockwise.

 

I turned the screw in so far I thought I might blow the pipes. I turned the screw counterclockwise so far I thought it might get so loose it would shoot off into space. (is it possible that it will come out if screwed too far?) neither made any difference on the gauge and this is a fairly new good quality oil filled gauge. Can these fail valves fail in such a way?

 

Why can’t you replace it with the same model? Why are you looking for a different model? Take off the bonnet as you say, open the union and spin it off. Do the reverse to install the new one. Seems like that would work.

It seems it would be safe and proper to do this. If you look at -

On page 1 of the link below, that is perfectly OK to do. They call it the “Spring Cage”.

http://www.watts.com/pdf/1910259.pdf

 

That is exactly what I wanted to know! I wasn't sure if I could take the spring cage off without parts flying everywhere or damaging the diaphragm but it seems perfectly acceptable to do so. I will be looking for the same model locally but may have to buy online to match it. Thanks for the research and info!

 

If you have never done it before then taking the valve apart, even just removing the spring housing, may indeed cause you to damage the diaphragm. Without trusting your soldering skills it might pay you to use a "Sharkbite" fitting on the non-union end.

 

Yeah I guess I could cut the pipe on the downstream side and put in a sharkbite coupling. Hadn't thought about that. I haven't done much with sharkbites but I guess they've proved their reliability. Thanks for suggestion.

 

MapGuy I have a Sharkbite now at my well pressure tank and it’s been fine for years, and I’ve used another for years in another spot and that was fine also.

I guess it would be possible to damage the diaphragm when removing and replacing the Spring Cage but the instructions certainly lead you to believe it is not a risky proposition, but marketers I guess (LOL) are not always totally honest.

I wonder, if you had a source close by where you could buy either the Sharkbite or a new PRV, you could remove the Spring Cage on the valve you have now, and maybe even put it back on, and see how you would feel about doing that on a new one. If it seemed like you could do that with no problem you could then go get the new PRV. If not you could get the Sharkbite.

But you would be without water while this was going on so that wouldn’t work if you had to order the PRV online. You can get the Sharkbite at HD and other big box stores.

If you look at this video from about the 12 minute mark I think this gives a pretty good idea how these things are put together, and of course you would not really be doing the repair – just removing the Spring Cage.

https://www.youtube.com/watch?v=f3AiX4Tq1kM

But whatever you decide good luck!

p.s. a little muddled above but either way you would need to buy a new PRV. I guess with the Sharkbite you wouldn't need to stick with the model you have now.

 

That was an interesting video and certainly tells me what to expect inside. I wouldn't even dare do all the work he did and expect it to work, but may go with the repair kit. I found one for around 50 bucks after shipping. Thanks. I'll try to post back with the results when I get it done in case anyone is still interested. Thanks to all up to this point!