PEX in the Sovereign

[Zeppelinium]

Let me start by saying that the entire water system was freeze damaged, so I had no issues regarding saving any part of the plumbing. Second, let me say that I've never found the 70's models to be particularly well-designed when it came to using space wisely or "dressing" the systems to look nice. Third, the mid-bath and kitchen in my Sovereign are together on the curb side, but Airstream insisted on putting the water service in the standard location, on the street side rear end, which forced them to run a pipe under the floor to cross the trailer. This pipe is highly susceptible to freeze damage in that location, not to mention durn hard to drain.

Here's the pee-poor layout under the cabinets. Note the totally inexcusable routing of the vent tubes straight through otherwise useable cabinet volume.



So, new water system, totally. My previous three refurbishment projects used copper. However, my latest Fine Homebuilding arrived with a glowing report on PEX (right after I bought the copper, but hadn't started work, yet). Ooooh, good excuse to buy new tools! I wanted the slickest installation I could do, so I elected to use crimped fittings. You must have a crimper (can be rented from local plumbing places--about $110 to purchase new). A tubing cutter isn't absolutely required, but when you're making very small adjustments to pip lenghts, on the order of 1/8", you can't do it any other way. After cutting PEX with a razor knife, about 2 cuts, I can't say enough for the ratcheting tubing cutter (about $35).



I could find many parts locally, but not the swivel female 1/2" FIPs or the valves. So I started with what I could locally, including the red/blue pipe, and ordered the rest over the web. Very good service out of PEXconnection in Oklahoma City.

Only one connection was difficult--the toilet. It has a 3/8" FIP inlet. I couldn't find one of those that (1) was 90 degrees and (2) had a 1/2" compression pipe fitting on the other end. I could find one with 1/2" tube, which is 1/8" smaller (go figure). But a short roll of tube at Home Depot is $35, ack! Local plumbing supply sold me a short piece of 1/2" tube, which makes a nice toilet connection with a 3/8" to 1/2" sweat insert.



...continued...

[Boondocker]

When I get brave enough I am going to rework the Trade Winds plumbing so I am not fixing leaks perpetually. I wonder how people with PEX in their campers rate crimp joints versus the non-crimp...

[Zeppelinium]

I began by removing all the pipe, the shower valve, and the bath basin fixture. I also removed the inside tambor under the sink and the middle shelf, the shelf under the basin, the bath exhaust fan, and the hot air ducts (temporarily--but they will be highly modified).

I also removed and reinstalled the electrical--bye bye Univolt, hello lightweight Intellipower. This is probably temporary, since it doesn't provide satisfactory access to the fuze panel.



I also removed the water inlet and vents for the fresh water tank. In doing so, I removed the tank drain and installed a new one with a bigger valve to allow dumping it in less than 3 hours.

Replacing the shower valve requires a special note. First, get a "shower only" valve. Otherwise, you'll have a short "down" tube for the tub outlet, which must be capped. This tube will NEVER drain, so you're always open to freeze damage. I found a Moen "shower only" valve at Home Depot. Second, this valve was originally sweated in, and I wanted to retain the through-wall fitting that the shower head hose attaches to. This required some interesting 3D juggling to get the new valve in and soldered.

The new basin faucet was a direct replacement, except it had 1/2" FIP fittings. I like these fittings--been using them for years. Easy to get a leak-free connection and they are standard if you intend to use risers. I wanted to eliminate as many connections and parts as possible, so I elected to go directly from the PEX via a swivel FIP connector. Worked great.



The hot water side was dead simple--a line from the top of the water heater around to the side wall, then along that wall to feed the basin, the shower, and the sink. The sink had 3/8" compression fittings, but there is a direct replacement to convert that to 1/2" FIP.

All lines are installed to either slope "down" gently, or lie flat on the floor. This is to promote good gravity draining of every part of the system. You can never quite gravity drain the toilet, since the valve is at the base and always has a small water column above it, up to the rim. I suppose you can open the drains and then stand on the toilet valve for a minute or two, which may be adequate, but I have a fitting that allows me to hook the air compressor to the street water inlet, and I blow everything out by opening each fixture's valve in sequence.

...continued....

[Chuck]

Originally Posted by Zeppelinium

Only one connection was difficult--the toilet. It has a 3/8" FIP inlet. I couldn't find one of those that (1) was 90 degrees and (2) had a 1/2" compression pipe fitting on the other end.

fwiw: I replaced this connection with a 1/2" compression coupling, and a length of braided flex-tubing(the sort that is often used for connecting toilets and lav sinks) that was made 3/8"FIP on one end and 1/2" compression thread on the other. simple, cheap...makes the 90 degree turn easily. got it at HD....

I agree, though, that the precious under-cabinet spaces are poorly laid out in this vintage. I'd like to replace my water tank inlet, too. The "factory" setup has this huge line descending at a 45-degree angle straight through middle of the only small galley cabinet I have. with the H2O pump taking up the other side...and the furnace using up the other half of the galley, that means that there is essentially no useable storage under the kitchen sink. none. how can that be???

in your pic...all those electrical connections in such close proximity to water drains and supplies....kind of makes me go "yikes!"

[markdoane]

I do the crimp thing. I think it's less a question of function as it is cost.

If you are doing a large trailer, or more than one, it could be cheaper to buy the crimping tool. The made-up compression type fitting can get a little pricy.

That said, I use the pre-made fittings if space or future disassembly is an issue.

[Zeppelinium]

the water pump was orignally under the sink. In order to achieve one drain line (one of my Airstreams has four--one pair in the front and one pair in the back--didn't want to do that again), I had to locate it back near the water heater. A big plus is that there was room to do so and open up the sink cabinet even further.

I made a module to support the pump and accumulator, that could go in and out as one piece. It also put the accumulator fill port in an accessible location (more on the modified cabinet, but weeks from now, I'm sure). I tested it for leaks before I installed it (it's a semi-pain to get at the screws that secure it to the floor).



One lesson learned here. The crimp tool requires almost 180 degrees of clear space out from the connector. I had failed to note how wide the tool opens and almost couldn't get the last crimp done to install the pump module. This could have been avoided with a little better planning.



In the under-basin detail above, you can see that it was tight getting everything installed and tight, but I can actually get a wrench on every fitting. The yellow wires wrapped around the red pipe were to the switch for the exhaust fan.

Note that the blue line to the water heater has a valve in it. Not a requirement, but I have found that there are times when I'm boondocking that I don't want to take 6 gallons to fill it up. Conversely, there are times when I want to drain the pipes (from my copper days), but don't want to drain the water heater (I'm a firm believe in mass--the fresh water tank and water heater are big enough that it would take a lot to freeze them. Not so, a pipe.) This valve would normally be open all the time.

Bad news. On first test of the system, the valve to the water heater leaks! Not onto the floor, but it doesn't do its job. Crap, bad place (tight) to have to remove and replace. If you have any way to test your valves before putting them in, I highly recommend it. This is a ball valve, which are usually very reliable, but not this time. I'd guess I've experienced a 7-10% leakage of this type in all types that I've purchased, so checking them is a good idea if you can figure out a fixture that will allow it.

...continued...

[Zeppelinium]

getting water from the fresh tank to the pump was a real problem. At first I thought I could just pass the tubes between the wheel well and the shower base. No soap!

This bath design has a seat. The panel under the seat slopes toward the wheel well, which pushes the sheet of supporting plywood back against the well. When you inspect the corner of the shower next to the wheel well, you find there isn't enough clearance to get PEX or vinyl tube through.



getting the front of the shower off was a problem. Once you remove the screws from the top piece of trim on inside, the top seems secure. It turns out that it's being retained by spring clips--you can remove it by using a suitable long piece of hard stock and hitting upward with a hammer.

The hower pan support rotates slightly, just enough to move the back edge away from the wheel well and provide enough room to saw off about 2". Once it's rotated back into position, you can snake the tubing through there with a little bit of an "S".

Why the vinyl and the PEX? First the vinyl is the feed from the fresh tank. The PEX going forward is for the drain. I wanted all the drain valves to be locted together in proximity to the tank drain. It also allows me to put the pressure relief valve up there, should I find the water pressure exceeding limits (a water pressure guage will be permanently insalled up near the drain, more on that later). The placement of this pressurized PEX line on the floor allows everything in back to drain down to floor level. A little dip of the nose and the floor pipes will also be drained--ready for cold weather!

When I reinstall the heating ducts, they won't have paths under the floor. The battery drain due to the heater fan just isn't worth it for me. I'll use it for space heat when it's cold, but once the weather is freezing, I go into a drained state and use bottled water for everything.

...continued...

[Zeppelinium]

You can recover from a screw-up. Just get a small vise and make a banding cut across the crimp, down to the PEX. Open the band up with a screwdriver and pry off. Getting the PEX off the fitting is a struggle, as it will have conformed to the ridges--I had to cut it off with a razor knife, taking care not to score the fitting.



At this point I have 54 crimps, with some small variability in their placement on the fitting, and not one leak.

Now, for the whole story--after thinking through the whole system, looking around a little, I turned on the pump. 95% genius (of course), and 5% stupid. The pump drew water from tank like a champ, the air disappeared, but no water came out of the faucet. Hmmm, what's going on (he muses without much fear)? Oh, crap, I left the toilet stub unplugged and it's dumping water like mad into the bedroom?! Argh!! Glad it was empty and the shop vac was handy. Just think, it's not going to get any better--I had my best days years ago...

...continued...

[Zeppelinium]

As I have implied in previous posts, the city water inlet at the curb side bumper may conform to standards, but it invites freeze damage due to the under-floor path it has to take to get to the fixtures (all of them being on the curb side). I decided to move it. In the end I had a number of criteria:

1. All water lines have to be level or descending to facilitate winterizing.

2. No new hole in the side of the shell.

3. Maintain the on board water pressure regulator.

4. Provide for a hose bib near the toilet for high pressure wash of the holding tank.

5. Allow the hose bib to function alone, eg, be able to prevent city water from filling the plumbing, in the event that you only want to use the hose bib (thus requiring a valve in the inlet).

6. Make this inlet valve readily accessible when you hook up.

7. Protect the valve from short periods of freezing weather, eg, overnight.

I finally decided the inlet should be behind the curb side wheel well. The valve would have to be recessed in the banana skin area. It took some pondering, but I finally figured out how to take a certified Rube Goldberg design and actually construct it an install it. To take it out require one sweat joint to be unsoldered, but all other components come out either with a wrench or a screwdriver.

a. Build the valve and its immediate piping. Make sure there is enough width to swing the valve lever.



b. Cut the access in the banana skin and drill two holes up through the floor. Note that there is a 1-3/4" lip extending outwards from the frame that is hidden by the banana skin--this is the main C-channel frame member that the banana skin is riveted to.



c. Insulate the assembly and install. It has to be pushed up higher than it's final position in order to sweat on an elbow fitting (inside next to the floor) going to the hose bib. The other side is attached to the pressure regulator through a double compression fitting (this allows the regulator to be removed easily).



d. go inside and sweat in the hose bib and crimp the PEX connections. All of these were tight fits for the tool--I had to remove the toilet to do the one in the left photo and the right one was a two-finger operation.



e. go outside and install the cover plate and sweat on the fittings leading to the hose inlet.



f. final look at the inside. this view is possible due to the fact that the wall between the bathroom and bedroom is removed. the wall fits about 2" aft of the hose bib and directly over the pressure regulator (small cutout required at the base of the wall, but the new bed will hug this corner so all will be concealed).



I think I met all my criteria. The pressure regulator drains in two directions--one through the system drain and one backwards down to the hose inlet. BTW, this old regulator doesn't have a check valve, so the outside valve (the one that prevents the hose inlet from getting to the main plumbing, if desired) has to be closed when not hooked to city water. Disregard the female hose connection--what was I thinking? The correct male connection will be installed tomorrow.

...continued...

[GreatPumpkin]

Roger - are you going tankless?
I didn't see a check valve to prevent city water from flowing into the pump and tank? The valve you installed in the banana skin will obviously prevent the pump from pushing water out the city connection when boondocking, but I didn't see anything to prevent the city water from backflowing into the tank - or am I just missing it?

[Zeppelinium]

The Shureflow pump has a check valve. It's been flawless in my Ovelander and Caravel. I had thought the pressure regulator might also have one, since the original Sovereign installation didn't appear to have a check valve, but not such luck. A newer regulator in my Overlander does have one, but I don't know about the Caravel since the female hose inlet connector has its own check valve.

[Angel73]

Looks to me you have the same toilet as us. And you have removed it can you tell me how.Ours is leaking and with the wall there its not so easy to get to with just a hole big enough for my hand.And i cant find any screw on the base to remove it...Is there something am missing to see here?

[Zeppelinium]

Angel,

I was able to get at both holdownd bolts from that access hole in the wall directly behind the toilet. If you look real close you can see the nut on top of the rear bolt.



The approved method of seeing the front bolt is to take the little circular insert that sits under the lid (if you're sitting on the john it would be under your left thigh) and look down through there. You can reach that nut with a wrench over the top of the foot pedal. I got to mine by reaching around from the back, blind, and finding it by feel.

[firefly007]

Led,
I just caught up with this post. Really nice work with the pex. I am new to Airstreams but not to mobile plumbing. Years ago I did a 69 Houseboat and endless household plumbing. I really groaned at paying $200 for a 1/2" crimper 15 yrs ago but I use it all the time. Back then it was grey polybutyl. Many people thought the pipe was bad but it was mostly the copper joints used with chlorinated water. The brass fittings are the way to go. The only fitting I have ever seen go bad was where the ring was laying on some mortar in a damp location for 5 yrs. Your post is a good guide when I redo my Bambi II.

Steve

[Streamin 65]

I too replaced all the plumbing in our Overlander with Pex. The 1/2" copper was in questionable condition so out it came. The 1/2" Pex cost about $20 for a 100 ft. roll which was plenty to replumb the whole trailer. I like the color coded you used! I only found it in white, so it all looks the same. I opted for the Quest pex fittings which basically screw together with a big adjustable wrench and channel locks. I'd guess the cost for all the fittings (most around $5 each) would probably equal that of a crimping tool and crimps. I did like the idea of being able to fix a leak on the road with nothing but basic hand tools, so I keep the big wrench and some extra fittings and a few feet of pipe in the trailer. The pex is supposed to withstand freeze/thaw cycles better than copper and is much lighter and was easily installed, especially compared to copper. IMO Pex IS the way to go! Great thread! --dave

[Zeppelinium]

The last function is the drain. You can see in the photo that there is a stop valve in the blue line which connects to the single drain pipe. This pipe also provides the fresh tank drain and the pressure relief drain. The pressure relief valve will screw into the same fitting where the pressure guage is now (you can see it sitting on top of the pressure guage).

I tested the pressure rise due to water heating; don't forget that I have an accumulator, which helps buffer any water expansion. With the system at the nominal pump pressure of 45 psi and water around 65 degrees, I turned the water heater on and set the temperature at the mid-point. System pressure rose to 65 psi when the heater turned off. I then set the temperature at max. The pressure rose to 90 psi. PEX can handle 400 psi, but I don't want the system to exceed 100 under any circumstances. 90 psi is too close, so I think I will install the pressure relief valve. If it functions, it only drains a couple of ounces to relieve pressure due to water expansion.

Done! But there's lots more to do on the furnishings and axles!

[kl8ton]

Fantastic install. . .super clean. I didn't read everything yet, just looked at pictures mostly. Do you have a tally of total cost? Do you know how much time you spent on this? Love the color coded lines.

[Zeppelinium]

This was a 2-day job that I managed to stretch into 2 weeks. I actually bought all the parts to do it in copper and changed my mind just in time. Then deciding on what type of fittings, learning about tools, waiting for some parts to come by UPS from an internet plumbing site, etc. The biggest design challenge was the external valve for keeping the plumbing dry if I wanted to get water to the toilet/black tank flush line--that probably took me three days of ruminating all the possibilities. And I bought lots of spare fittings and two 100-ft rolls of PEX (I've got another AS remodel on the horizon).

Bottom line, the real work was about 2 days and the cost (not including pumps, regulators, new faucet, etc--just the plumbing) was between $50 and $60.

One unexpected result is that the pump is very loud as it approaches the cut-off pressure. This is a surprise, since it has its own rubber isolators. It may have something to do with the way I mounted it on its own panel which may be acting like a drum. More investigation required...

[LI Pets]

Just wondering why you used so many 90's instead of just letting the tubing bend on it's own.

How tight a radius can this tubing make?

[j54mark]

Originally Posted by Lipets

Just wondering why you used so many 90's instead of just letting the tubing bend on it's own.

How tight a radius can this tubing make?

If you buy the coils, it can turn on an amazingly tight radius - four times it's diameter, if I recall (in the direction of the bend, of course). That means 1/2" Pex can turn on a 2" radius.

Mark