Thread: What is this fitting?

First time I ever saw either of these fittings. Second photo looks like some type of expansion check valve type device, but I have no idea what the first photo is.

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The first photo is a back flow device, either a dbl check valve or an actual backflow device. Most of the time this seen in comerical buildings but more and more they are going to be seen in residential city water systems. These are used to prevent the back flow of water and any contaminates the water lines can pick up, from going back into the city water system. We are seeing more and more of these or some type of anti backflow valve on residential houses. You see more and more people watering their lawns with a canister attached to the hose to provide some type of fertilizer or help grow agents. With out a backflow there "could" be a possiable back feed from the city water system bringing in the chemicals into the main water system.
I am not sure what the 2nd photo is by the picture.
Hope this helps.

The first valve is a Watts "Series 009 Reduced Pressure Zone Assembly" with "two, in-line independent check valves, replaceable check seats with an intermediate relief valve, and ball valve test cocks." Yikes!

See... Watts: 009 | Reduced Pressure Zone Assemblies | Backflow Prevention

I can't find the 2nd, but I would guess an adjustable(?), pressure only, relief/check valve? With the plumbing looped the way it is I can't imagine any other purpose. Perhaps the plumber was out of the normal pressure relief valves and "cobbled" this into the set-up? Where was it plumbed to off to the right?

This was on a hydronic heating system?

That looks like the right one. Both valves are piped to a floor drain off to the side, along with the water heater relief valve. The first fitting (larger one) is on the main water line. The second fitting is on the cold water input line to the water heater. The heat is forced air, with a natural gas water heater. Goofy, huh?

Jim,

The 2nd valve has been bugging me all day. My initial thought was that it was a trap primer. I dismissed that when I enlarged and lightened the photo and saw how it was plumbed in a closed loop.

There would be no way for it to function. Water effectively has to flow through the valve for it to discharge any water to the trap. But...still it looked a lot like a watts primer, although not one of theirs.

I believe I finally found it. I'm 99% certain it's a Zurn trap primer presumably for that floor drain. See http://www.zurn.com/operations/light...lation/LC6.pdf .

With that wierd loop, pressure will be the same either side, no matter what happens at the water heater intake, and I just don't see how it could possibly function.

My final vote then...a trap primer plumbed incorrectly.

Or a tempering valve plumbed incorrectly. (the second one)

Do you know what the double check valve is there for? There has to be something the DCVA is protecting the potable water supply from to go to the trouble and expense of installing it.

Originally Posted by Ken Meyer

Do you know what the double check valve is there for? There has to be something the DCVA is protecting the potable water supply from to go to the trouble and expense of installing it.

Hello eveyone here is the un intellegent Penguin here

IT is not a double check valve
the actual term is reduced back pressure assembly (RPBA)
the main difference is the air gap between check valves when water is dripping or pouring out the air gap in the middle where the basket is you have a problem - a check not sealing to be precise. this indicates that the valve req service and testing to meet city codes - its been a few years since I have done back flow training though and I'm a little fuzzy.

the double check valve is similar except it does not have the air gap and drain in the middle of the bottom
the other is a trap primer as previously stated

the rpba is there to protect the city water from contaminants. likely as since the water heater is used for heat the inspector called for it to be installed (rob said they use the heater to heat water for a fan coil?)

Good day every one and happy inspecting