Water pipe puzzle

[Woodywhite]

Anyone like doing puzzles? I've got a 1960, 18' Traveler (my first trailer) I bought about two months ago. I've worked through the rest of the systems and started to check out the fresh water system. As I tracked the system from end to end, I have found what appears to be an open pipe out the belly with no apparent way to shut it off.

Pipe comes from the fresh water tank, which goes to T1.
T1 to the right is drain, with the red handle, which drains out the belly
T1 to the left goes to T2.
T2 to the right goes to the sink and hot water heater
T2 to the left goes to T3
T3 straight goes to the city supply line below the belly.
T3 left goes to the mystery line, which seems that it would continuously drain the system.

Plumbing should be pretty straight forward, but this makes no sense to me. Am I missing something?

Thanks,
Bob

[azflycaster]

Maybe that is a pressure relief valve between the T and the mystery drain. If the pressure in the line exceeds a certain point it would open to prevent damage to the system.

[IndyAnne]

Hi, Woody, I wonder if you might be missing the city water pressure regulator?

Or, maybe the line that seems to empty out is the "in" for city water.

Or, maybe the line is for winterizing and somehow is missing a valve.

My 68 Trade Wind had a three or four lines that exited the belly pan. All of them had some sort of valve. One line was intended to connect to city water, leading to a pressure regulator. The pump, connected to the water tank, had a valve to shut off the pump from the system in order to use the city water.

I took everything out, however, in replacing 4 feet of rear flooring and replaced with PEX lines. I have not yet replaced the city inlet and regulator since we have camped mostly without water sources, using only the tank and pump for our system.

I suppose if I sell, I will need to think about this.

Good luck!
Anne

[Woodywhite]

Hi Richard and Anne,

A PRV is an interesting thought. I've only dealt with home water systems so I've never seen one this small and didn't consider that possibility. The city water in also has kind of an interesting shape, but I assume that's a backflow prevention feature. I guess I'll disassemble a couple of joints and see what's inside the fittings.

I need to sanitize the system and test for leaks anyway so I might do this first and see what other fittings I need in case I need to make a run to the plumbing store.

One way or another, I think I need to add a shut off valve of some kind to this pipe. Even if it is a PRV, they have been known to stick open when they mineralize.

Thanks for the leads. I'll follow up either tomorrow or this weekend.

Bob

[Woodywhite]

OK. Test run complete. As I thought, when I run water through the system, it runs straight out the mystery pipe and onto the street.

For the moment, I just capped the end of it so I can get the rest of the system on line. A PRV at this site does make sense, so in the future I'll install one.

Bob