Mystery Plumbing Part...

[bludatta]

Hello, I hope someone can help me. I am doing a total re-plumb of my 1970 Overlander. I am taking pictures of the whole process and I will post when complete, it may help someone in their adventure! Pex will make me happy.

Anyway, downstream from my pressure regulator is some mystery part with a hose attached to flow outside. I already have the new regulator and check valve to install, but I'm not sure what this thing is. Anyone know?

[Inland RV Center, In]

Originally Posted by bludatta

Hello, I hope someone can help me. I am doing a total re-plumb of my 1970 Overlander. I am taking pictures of the whole process and I will post when complete, it may help someone in their adventure! Pex will make me happy.

Anyway, downstream from my pressure regulator is some mystery part with a hose attached to flow outside. I already have the new regulator and check valve to install, but I'm not sure what this thing is. Anyone know?

That is a high pressure pop-off valve, called a 111 valve in the Airstream language.

As it ages, it has a tendency to not seal correctly, allowing water to drip.

Parts stocking dealers would have them.

Andy

[ROBERT CROSS]

Not using the assembly?

I would take it off the manifold and see if it flows directly thru, may be nothing more than a fancy drain for blow-by.

Bob

[vswingfield]

It's a pressure relief valve. I've been searching for one for sale online just for illustration but haven't found one so far.

They are normally closed, but the drain lines are there to route the water outside in the event abnormally high water pressure forces water through the valve.

On edit: found one at Inland RV.

[Tom Nugler]

My repair manual indicates it's a relief valve. There are instructions in the book on how to replace it but no listing in the parts list. Go figure.

Tom

[bludatta]

Thanks for much for your replies.

A high-pressure pop-off valve? AFTER the pressure regulator? That seems backwards to me. I wonder how important it is with a new pressure regulator anyway.Suggestions?

[markdoane]

Sure. It protects the plumbing after the pressure regulator and check valve. Especially when you fill the water heater with cold water and turn on the gas.

[vswingfield]

Originally Posted by markdoane

Something weird is going on. I posted a reply on the Airforums iPhone App. It was a duplicate of Vaughan's post, so I went to the regular Airforums page to delete it. When I got here, I found that Andy's post was there, but does not show up on the iPhone app. Wha??
Does this happen often? Do "Vendor" posts not show in the iPhone app?

I've noticed delays like this before. His reply didn't show up till after I had posted my reply for me either. I just checked on my iPhone app and Andy's post is showing up on mine now.

Even stranger about the iPhone app, though. Compare the choices from the "Forums" drop-down menu from the tab at the top of the browser window to the choices available from the Forums button at the bottom of the app window. Way different! The "Technical Sections" are not there at all on the app.

Originally Posted by bludatta

Thanks for much for your replies.

A high-pressure pop-off valve? AFTER the pressure regulator? That seems backwards to me. I wonder how important it is with a new pressure regulator anyway.Suggestions?

Actually, you want it after the regulator. That way it comes into play if there is a problem with the regulator. This way the regulator gets first chance to deal with the water pressure.

I'd keep it, myself.

[bludatta]

Thanks again, I will order one ASAP. It says "Poppet Style" and does not have a drain on it.

[vswingfield]

Originally Posted by bludatta

Thanks again, I will order one ASAP. It says "Poppet Style" and does not have a drain on it.

You should be able to take the old fittings with the drain attached and use them.

I notice that the one in your link is set for 75 psi and the one at Inland is 125. From following your link I located this one http://www.pexsupply.com/Zurn-12-P15...e-Relief-Valve that is a 125 model. You may want to consider it.