Check valve?

[Chuck]

I was staring at this bunch of plumbing over the weekend while replacing the ball valve on my toilet, and it got me thinking:

I have the common problem of water dribbling out of the city water inlet while running the pump. I understand that there is a check valve in the system that keeps the water from escaping like this, but its location has eluded me. (and its not that big of a deal; hardly ever dry-camp, but anyway...). My owner's manual (don't have a service manual) mentions it, and says that its location is "under the street side wardrobe". well, I don't HAVE a street side wardrobe; its a twin setup. ("duh" to the 1973 techwriters ). someone here suggested that it might be under that twin bed, but I haven't had the gumption to delve into that just yet.

So anyway, while futzing around under the bathroom sink yesterday, I was looking at the plumbing coming in from the street, and got to thinking: is this thing the aforementioned check-valve?? (red arrow). I know, the bell-shaped thing is the pressure regulator. the pipe coming out of the (?) appears to be some sort of relief tube. can't see it in the picture, but the copper pipe coming out of it connects to a piece of clear-tube that goes straight down through the floor and out the bottom of the trailer.
Looking at the rest of the pipes there, it seems to me that if there were a one-way valve further up toward the front of the trailer, there'd be no way for water to get to the bathroom fixtures at all while running on the pump.

[thenewkid64]

The red arrow points to the overpressure pop off valve. This is to allow a surge to release if you are on a campground system that is over 50 PSI. I belive the check valve is in the internal pressure regulator . This is the bel shaped thigy upstream from the pop off. The $1.49 solution is to put a cap in the city water hook up when it is not in use. If you use the water for cooking/drinking/etc. from the campground you want to keep road crud out of this fitting anyhow.

[Chuck]

Yeah, I've seen people mention this "pop-off" valve...that's what I thought it might be. I wonder about it, though...isn't the pressure regulator supposed to down-regulate any pressure in excess of "normal"? or perhaps, does this thing handle excess pressure coming from the pump? fwiw: the pressure at my house is >50psi, and nothing comes out of this relief valve when hooked up to the hose in my driveway. (well system with a pressure gage attached..set to about 65psi.).

the check valve functionality being in the pressure regulator itself seems to make sense, but wherever I've seen it mentioned, people refer to it as a seperate device...like my owner's manual, for example. Even though they say that its located under the wardrobe, it would make sense that there wouldn't be "much" difference in the plumbing between a "twin" and "double" of the same year. then again, mine could very well have been re-configured at some point. In fact, that plumbing work in the pic does not look 30 years old to me...you can still see shiny, white teflon tape on the fittings. It may have been done just over a year ago, when I bought the trailer. (trailer had leaks when I went to pick it up from the POs; they took it to their repair guy, and I picked it up from him when the leaks were fixed, and the po's paid the bill. never got a chance to talk to him about exactly what was done, where the leaks were, etc.....).

one of those "plugs" is on my list, anyway. they don't have them at HD, believe it or not. One thing I tried was a shut-off valve that is meant for the end of a garden hose, and fits in the 5/8 thread. I figured that would do the same thing with the ball valve set to "off", but water leaked out of the valve. I guess its only meant to stop the flow in one direction (?).

[thenewkid64]

I have had my pop off drop water if I do not use a spigot pressure regulator. WIth high pressure flowing thru an open faucet when you cut it off the back pressure can cause it to relive the excess. The pressure regulator in the system I think is set to 45 PSI, the pop off is higher. It is alos a secondary releif for backpressure created by the waterheater just in case the T&P valve does not let go.

[drboyd]

...with that problem!

I put a hose plug in the outside connection - I got it at Homey D, but I had to put together two parts to do it.

The other option is to add an additional check valve in the city water inlet line, but I'm thinking I'll just keep the plug. Maybe I'll put it on a chain, so I won't lose it....

[Chuck]

Ok, that makes sense. So...other trailers that have the check valve somewhere else, not integrated into the pressure regulator, must work something like this drawing....

but mine "must" be in the regulator itself, because the main water supply goes directly from the regulator to the sink/shower/toilet. right? and the only way the pump could supply those lines would be if the check valve was in the regulator....

[drboyd]

...matter of fact, that little gadget to the right of the regulator in your picture looks like it could be a check valve.

[Chuck]

I don't see anything to the right of the regulator in the pic, except for the back of the shower wall...(?). Unless you're talking about the 2 "lobes" that point downward below the bell-housing of the pressure regulator...that's all part of the same housing. you just can't see it because the view is blocked by the pressure relief tube.

[thenewkid64]

I think what Drboyd is referring to is the part of the pressure regulator that extends from the bell shape. Where the inlet line treads in. It looks like ist could be the check valve, but cast into the body of the pressure reg.

[drboyd]

....http://www.wastewaterdepot.com/valve_brass_swing.html

...only it's upside-down, and cast into the regulator....

[Chuck]

yeah, it does look like that. That must be it, then!

boy, I tell ya, I hope I never have to take any of that stuff out. it would be an absolute bear to get at that. The picture doesn't really tell that story, at all. Its easy to see, but impossible to reach, at least with 2 hands and the wrenches that would be needed to install/remove it. This stuff is located in the street side rear corner of the trailer. You can see it by opening the bathroom vanity door, sticking your head in, and turning to the right. its sort of under/behind the shower stall. I don't understand why they didn't put an access panel in the rear of the trailer above the bumper. you could easily access it that way. you can't even get at this from underneath, because it is all above the plywood floor. Anyway, it looks to me like you'd have to dismantle the entire bathroom to access it.

[85MH325]

THIS is a timely thread...

The check valve in my '94 was allowing the system to lose pressure when using the pump. Same problem, it was allowing water to drip out. I did the plug routine, but until the pipe fills up, it continues to dribble down.

I had a similar problem in my '85 motorhome when I bought it, but it was just a piece of crud stuck in the inlet. I managed to clear it, and it was fine. The check valve in it was inside the city water inlet fitting.

On the '94, they use a plastic, one-piece $40 inlet/pressure regulator. No such luck as just having gunk in it with this one. The rubber flapper 'valve' had deteriorated and was shot. I ended up not only replacing the inlet/pressure regulator, but several inches of plumbing and putting in a new fitting. It was a ten minute job. (Only took me several hours... )

I could be wrong, but I think that the check valve in my '70 Safari was also an integral part of the brass city water inlet assembly. I also had a brass pressure regulator similar to the one pictured. You might just have something stuck (a small rock, or gunk) in the inlet/check valve that can be cleaned out.

Roger

[Chuck]

How would you suggest I go about cleaning it out? Like I said...damn hard to access this thing.

I don't think there's anything at the city inlet other than regular-old 1/2 inch pipes/fittings. The connection is in the rear streetside corner, right along side the frame that sticks out from the belly pan, and it just goes straight up into the trailer. from the inside, I can see it coming up through the floor...just 1/2 inch pipe that goes into the regulator pictured above.

[85MH325]

Originally posted by chuck
How would you suggest I go about cleaning it out? Like I said...damn hard to access this thing.

I don't think there's anything at the city inlet other than regular-old 1/2 inch pipes/fittings. The connection is in the rear streetside corner, right along side the frame that sticks out from the belly pan, and it just goes straight up into the trailer. from the inside, I can see it coming up through the floor...just 1/2 inch pipe that goes into the regulator pictured above.

If it is cast into the regulator, I'm not sure how you'd do it.

Big help, huh???

The only thing that comes immediately to mind is to pull the regulator out (yes, I know that you need to grow tentacles that will hold wrenches to do it) and see what's inside the inlet side.

I guess that first you could try backflushing it by putting a waterbed-fill type fitting onto your sink faucet and then hooking a hose up and charging it (not too much pressure tho) and see if it will wash anything back out. The downside to that, of course, is that the valve is designed to shut and not let the water out. The only glimmer is that if there is something holding it stuck open, that may have enough back pressure on it to flush it out. Maybe...???

Roger

[Chuck]

I guess that first you could try backflushing it by putting a waterbed-fill type fitting onto your sink faucet and then hooking a hose up and charging it (not too much pressure tho) and see if it will wash anything back out.

Wouldn't that be the same thing as just putting some water in the fresh tank, and turning on the pump? I could just let it run for a while, and see if it ever stops dribbling....

[85MH325]

Originally posted by chuck



Wouldn't that be the same thing as just putting some water in the fresh tank, and turning on the pump? I could just let it run for a while, and see if it ever stops dribbling....

yes and no... you can vary the pressure up to whatever your city water pressure is with the hose. hopefully, brief exposure to a little higher pressure, especially with pressure escaping, won't cause a failure. the pump only charges the system up to a constant pressure of what it is set at (40 psi?)

or, when I replumbed the Bambi, I found a hardware store that had brass check valves. I just installed it down stream from the city water inlet but before anything else. perhaps that would be easier than worrying about the one inside the regulator.

Roger

[pepper48]

Before you go to the effort to work on the check valve you found, you need to make sure it is the right one. Most Airstreams have two check valves. One is down stream of the pump to prevent shore water from entering the pump and the fresh water tank and the other is down stream from the shore water inlet and prevents water from exiting the shore water connection.

My Trade Wind has a bad shore water check valve too. My solution, so far, is to use a PVC plug from Ho Do screwed into the shore water inlet. I checked the plug before buying by taking it over to the garden area and screwing it into a hose. A local RV dealer tells me that they make the female shore water hose adapters with an integrated check valve. I haven't investigated this option. So far the plug works fine for me.

[drboyd]

...thread plug at Homey D, with a 1/2" ID threaded hole. Another solid brass plug 1/2" OD threads screwed right in, with some teflon tape.

I'm gonna try to get fancy, and tap a hole in the smaller plug, for a screw and a chain, so I won't lose it.

[MarkE]

I am reviving this thread to report that on my last outing (1st time using the Airstream for this year), out of the blue, the water pump kept cycling on/off every few seconds when all taps were closed.
Oh No, thinks I. I have a leak somewhere! I searched all the plumbing that is visable from inside the coach and couldn't find a leak. So, after thinking about it awhile, I went outside and discovered the water exiting at the city water fill pipe (it really shot out when I removed the cap and turned on the trailer's water pump).
So, like some of you I decided it must be a failed check valve but when I started to look for the valve, like some of you, I couldn't locate it.
One of guys from my WBCCI unit noticed me looking around in the trunk area of my trailer (if you ask him he'd prob. say he noticed me looking bewildered). He agreed that it must be a bad check valve BUT he showed me what he had done to his trailer when he had this problem.
So, stealing his idea, last week I made the following repair:
'Forgot about locating and removing the check valve. Instead, I got a 1/2" lever valve (about $5.00), removed the short stub with the hose threads from the end of the pipe on the trailer. Using a bit of thread tape, I screwed the valve on in place of that stub.
Then, screwed the stub with the hose threads onto the outlet side of the new valve.
DONE!
This modification adds about 1 1/2" to the length sticking out of the trailer. In my case, I do not think this will cause any clearance problems 'cause it is located between the rear bumper and the rear of the trailer, on the road side. So, I think if I were to snag it on anything I would have to, first, bash the coach body and/or tear up the bumper (either of which would have me overlooking the damabe to this water inlet.)
It works great. 1/4 turn and it's open for hook-up to city service or 1/4 turn and it's closed for using onboard water supply.
Now, here is what I think is an extra benefit to this setup (beside being a simple, quick, cheap solution to the check valve problem): when I am hooked-up to a water source and am going to be away from the site for the day and evening, I can walk to the rear of the trailer, turn the lever a 1/4 turn and not worry about what would happen if a pipe should develop a leak inside the trailer while I am gone.
A real neat feature, especially with the daisy-chain water systems used a some rallies.

[C Johnson]

Last weekend I dug into fixing some of my plumbing problems. Moving my water pump to gain some space in the utility cabinet, isolate the water pump more from the copper lines to lessen the noise that it makes and fixing my pressure relief valve. I'll stick to the topic here.

During my 2 week trip last fall my pressure relief valve started to fail causing my pump to cycle on and off and lose water from the tank. So the short term fix was to put a bolt in the drain tube.

Here is a pic of the pressure relief valve you can see it just to the right of the regulator with the drain tube going down thru the floor. The middle one is it out and the last pic is of my guage and new placement of the water pump. Here is a link to a larger size of the picture to the left. Link to the picture on the far right.



This was a bear to remove. I went to the local plumbing store to find a new one. They did not have one but told me that they are still available from Watts Regulator Co. It is a type 53 pressure regulator. It can be viewed here. I can get them from a different supplier here in town.

I got to thinking, do I really need this thing anyway ? I have a regulator in the AS and one on the hose for the hook up. I asked the plumbing guru at the hardware store and his reply was that he didn't see why I had to have it in a travel trailer. Soo ok, I'm not satisfied yet. I bought a pressure guage to put back in the place of the valve. I wanted to see what kind of pressure I had to begin with from the Sure Flo Pump and from the city water connection. I haven't tried the city water yet, I will soon. What I did find out was that the 12v pump will hold 50 psi static pressure. Which makes sense. Now I know why my 40 yr old valve was leaking. The springs got weak and the rubber was shot to boot. One thing I did find out was when I start the hot water heater the pressure in the system will rise to above 60 psi as the water heats in the HWH. Now I am thinking I may actually want to put this thing back in. ( I mean a new one ) . I like having the guage on there. It takes the guess work out of things.

Does anyone have any thoughts on this ?

On a side note, I relocated my pump and it is much quieter, plus I have a place for my jack stands now. I wasn't sure about mounting the pump on the wall of the utility bay, but it seems to work fine.

I welcome any comments on these subjects. I don't mind changing things around to make it right.

PS - I have a new pop-off valve on my HWH too. That was done before I even started using the HWH last summer.

Chris