Fresh water tank modification, new suction line.

[Raspy]

With all the talk lately about not being able to access all of the fresh water in the tank, I decided to make a new suction line and improve the situation.

 

The stock line on mine will only draw water down to about 1 1/2" deep before it begins to suck air.  In a 35 gallon tank that is only about 4" deep, this means about 1/3 of the water is not available, or about 11 or more gallons left in the tank.

 

The stock pickup is on the side of the tank and cannot get all the water.  So I made a top fitting that goes down and picks up the water at or below 1/4" from the bottom.

 

When I started the installation I leveled the trailer and ran the water until it began to suck air.  Mine did that at a reading of 25% on the gauge.  If the front of the trailer is raised some, which I did not do, the reading would still be the same when the pump sucked air because the gauge reads right next to the pickup.  You could get more water out of the tank with a raised tongue, but the gauge reading would be the same when it sucked air.

 

After I installed the new dip tube, I continued to draw water and it began to suck some air at 6%.  So, mine went from 25% (approx. 8 gallons left) down to 6% (approx 2 gallons left) when it began to get some air.   Others have reported as much as 38% remaining which would be over 12 gallons.

 

At a 6% reading I began getting aerated water, but a steady flow.  Finally, the gauge went to 0% left.  At that point is was about 1/2 water and 1/2 air at the faucet, but still flowing, or spitting.  But even with a zero on the gauge it continued to pump out another gallon or so before I shut it off.  All of this with cold only, not water drawn from the water heater.  So, the volume from 6% to 0% was totally useable, probably not for a shower, but certainly for drinking.

 

This is a prototype that works well, but it might still improve a bit with the next one.  The pickup touches the bottom of the tank, but draws radially from below 1/4".  It adjusts to any small differences in various tanks.  It can be pulled out and cleaned easily if debris ever clogs it.  All plumbing connections, where the new line ties in, are easily accessible and the existing tank fittings are not touched.  The stock tank drain is retained.   The area of the tank where the new fitting is installed is easily reached and the tools to do it all fit in the available space.

 

After clearing all of this with Oliver to make sure there is no conflict with forum rules or warrantee issues with them, I can send anyone that wants to do this, a kit with the following:  the pre-made dip tube fitting, a Polyethylene tank fitting, the special spin weld fitting driver, a 1 1/2" hole saw (if needed), the pinch ring tool and a PEX cutter.  I'll also provide step by step directions for anyone who is interested.  You'll have to have a powerful router with a 1/2" collet and a drill to drive the hole saw.

 

Or, I can help you with a set of directions here on-line and you can assemble the parts yourself.

 

The parts required are:  (1) dip tube assembly, (1) 3/4" spin weld fitting, (6) 1/2" PEX pinch rings, 24" 1/2" PEX, (1) 1/2" PEX ball valve, (1) 1/2" PEX tee, a small container of Rectorseal 5.

 

The only real tricky part is the spin weld.  Besides the special procedure for spin welding itself, you have to  make  a new hole in the tank and vacuum out the chips.

 

Here are some pictures:

 

 

[bugeyedriver]

Nice mod for a persistant problem.  Did Oliver sound like they might incorporate this style pickup in their new trailers, or offer it as a mod they would do in the service departmnt for those of us who may be mechanically challenged?

[John E Davies]

Jason told me two days ago that they are developing a retrofit kit that can be done there in Howenwald, or sent to a shop or skilled owner for installation. They have to finalize the design, make sure it meets the various codes and certification, and test fit it them into a couple of trailers on the production line, before making them available. They want to make sure they do not introduce any new issues while fixing this old one... A wise move IMHO.

 

I can wait until they have a factory fix available, since my trailer is only a month old. But John "Raspy's" fix looks solid, well put together and easy to do for somebody out of warranty. Thanks for making the parts available.

 

Can you comment on the spin welding, and how hard it is to get good results if you have never done it before? I have seen videos of the technique.

 

Thanks,

 

John Davies

 

Spokane WA

 

 

 

 

[Raspy]

Pete,

 

Oliver hasn't responded to my phone message yet.  I called Jason to talk to him about this, but missed him and left a message.  Bu,t they did say, in their open letter, that they were going to hire an "expert" to solve this issue.  It's really just a common sense approach to an obvious problem and probably the way they should all have been made.  Normally, the side outlet they install would be fine if the tank was a tall narrow design, or had a sump in it.  But with a flat tank, the side fitting leaves about 1/3 of the water trapped in the tank.

 

This method completely solves the issue and the fitting can be easily pulled out if needed.  Plus it leaves all of their existing plumbing in place and is installed in such a way that is easy to reach.

 

The original tank drain is extremely difficult to get at, so any new fitting that would go through that hole would be so hard to install.  I looked at it, but it's not practical to do it that way, plus, no matter what new fitting I designed to go through the existing hole, it would not pick up reliably below 1/4" like this new design does.

 

It took a while to figure this out, assemble the parts, make the prototype and do the first installation with the spin welding procedure, but I think it's the right fix.

[Raspy]

John,

 

The spin welding procedure is very quick and easy, but it MUST be done correctly or it would be a disaster since the tank is in such a difficult spot.

 

I had never done it before, so I ordered the parts and practiced with a couple of fittings on a five gallon flat sided jug. The jug wall thickness is about 1/2 what our water tanks are.

 

It also requires a powerful router with a 1/2" collet.  1 1/2 HP seems about right for these 3/4" fittings.  A slight down force that will allow the router to come up to full RPM, the tool held perpendicular to the tank wall, steady but slight down pressure.  Two seconds max time and then release the switch.  Continue to hold the slight pressure until the molten poly sets.  If done right, you'll see melted poly all around the joint and you won't go through and ruin the attempt.

 

I found the pipe thread wanted to cross-thread, so I ran a 3/4" pipe tap into the fitting before the weld.

 

It's remarkably easy, but scary.

 

Here is a pic of the router with it's depth plate removed,  the driver installed and the tank fitting in the driver:

[Mike and Carol]

Let's have the next rally in Nevada and John can do us all!  I have a big router but doing this would make me a little nervous.

[Raspy]

Let’s have the next rally in Nevada and John can do us all! I have a big router but doing this would make me a little nervous.

There's an idea!  Plus we could hang out by the river, enjoy the Pine Nut Mountains and remember why it's so nice to be out in the great outdoors.  In fact, we could probably host twenty or so right here!  Tonight, I'm sitting here after 8:30 PM.  Up on the porch and looking at the incredible Nevada sunset.  Frogs are croaking, the sky is orange, the scent of sage wafting as the sky darkens.  It's magical.  A warm high desert breeze slides down the mountain after hot day.   We call it the "evening performance" as the sun shadow crosses the eight mile wide valley and the day concludes.  It's all worth planning the day around.

 

So, with a barbeque, some great conversation, plenty of room to set up and the incredible Nevada sky, all while doing a few tank modifications, I'd say Yeah!!!  We'd have Ollies till the world looked level.  And everyone would be able to have more water when it was all done.  It's the kind of experience you read about, with incredible Nevada and high desert scenes and stories.  Too bad our coyote doesn't live here anymore or you'd all have her sitting in your  laps and wanting to start a game.  Can you imagine a Nevada sunset with a coyote in your lap?  Now there is a western scene!

 

I'll probably sit out here for a while yet.  Our dog Gogo, is surveying the yard.  Chiming clocks remind us once in a while.  The frogs make me wonder about frogs in the desert.  Venus will appear soon as the moon waits for the right moment, beyond a distant horizon, to show up.  A fading bit of orange, silhouettes the mountains north of us and I'm reminded of why I went for this place to begin with.

 

Enjoy.

 

 

[KarenLukens]

Excellent work John :)

 

Once Oliver gets it approved, I'm ready :)

[John E Davies]

Is there room on top to install a 4 inch or 6 inch round deck plate with gaskets, for access to the inside of the tank.? Then you could use a flanged bulkhead water fitting with gaskets for the suction pipe, and also clean out the tank periodically through the port.

 

It would not be likely to leak, being on top and not constantly submerged in water.

 

 

Are you lending or renting your spin weld tool? What are you charging for the parts and tool? They are not cheap....

 

http://www.vintagetrailersupply.com/Spin-Weld-Driver-Tool-p/vts-624t.htm

 

Thanks.

 

John Davies

 

Spokane WA

[T-Oliver]

Elegant solution

 

Mine is 2 weeks into production, we will see what we get.

[Raspy]

John,

 

Remember, there is no glue that works on polyethylene.  It's inert and that is why it has to be welded.  So with any mechanical connection there must be a gasket, or thread sealer or something.  Those deck plates have a small O ring and the tank is flexible.  Screws would have to go clear through and be nutted.  Not a reliable system for a poly tank.

 

I'm not sure there's room to get it in there either.   Maybe.  I'll look later with that in mind.  I'm  not confidant that it would hold the sloshing  impact of the tank water.   If so, and you could get your hand in there , it would be a way to install a bulkhead fitting for the suction line.  I don't think I'd trust it.

 

Another way to gain access later would be to install a 1 1/2" spinweld fitting and then bush it down to 3/4" for the new dip tube.  Later, if needed, the bushing could be unscrewed to give a large enough hole to get a vacuum hose in.

 

As far as renting/lending the tools, etc.  I'm not doing any commercial stuff till I discuss it with Oliver so as to not conflict with their forum rules.  It might be possible to rent the stuff and each person do their own work, but that seems unlikely.  It might be possible to do the mod at a rally.  Who knows at this point.

 

It is definitely a good fix though.  It works and it retrofits fairly easily.

[KarenLukens]

Did Oliver call back and approve it yet Dad? I don't care! I want it now!

 

 

Hahaha :)

[Raspy]

Reed,

 

I haven't heard back from Jason. Don't know if I will.  Maybe you should call him, since you know him better than I do.

 

We can do your tank at Bandon if you'd like.

 

 

[topgun2]

There's something about "having my tank done" that I like!

 

Bill

[KarenLukens]

Reed, I haven’t heard back from Jason. Don’t know if I will. Maybe you should call him, since you know him better than I do. We can do your tank at Bandon if you’d like.

 

I called Jason... It sounds like they are either adopting or using your set up John. They are waiting to have it approved. Jason wasn't familiar with this thread, so he's going to look at it and call me back.

[Overland]

John, since you say that you stick the tube all the way to the bottom, I assume that you're picking up water from the four holes that you drilled at the bottom of the tube, plus whatever would get around the end of the tube.  I'm curious if that's roughly the same area as the original pex opening and if not, if you feel like you're losing any water pressure or if you think it might put extra stress on the pump.  It's an elegant solution, btw.

[Raspy]

Overland,

 

The dip tube that is in the picture is designed to go all the way to the bottom of the tank and sit against the bottom.  It is designed with a bit of extra length to accommodate tanks that may be slightly different from the normal overall depth by dropping all the way to the bottom in any of them.  If you look closely, you'll see the end is capped.  This particular style sweat cap was picked because it is flat on the end and has rounded smooth corners.  In other words, it is very kind and won't dig into the bottom of the tank.  All of the water enters around the perimeter of the cap, not the end of the pipe.  The cross-drilled pickup holes were drilled tangent to the inside surface of the cap.  If you add the diameter of the pickup holes to the thickness of the cap wall, it comes to just under 1/4".  The top of the holes are 1/4" or less, from the inside surface of the tank.  This arrangement will pick up water down to about 1/4" deep and do it consistantly in any tank it is installed in.

 

As mentioned earlier, mine began to get some air at 6% tank level, but ran until the gauge read 0%.  At that point it was sputtering, but still drawing enough water to drink, but not to shower.

 

There are four holes.  The surface area of all four holes added together equals about 1.7 times the surface area of the inside of a PEX fitting.  Allowing for the vena contracta of the flow through those four holes, the restriction is still less than each PEX fitting used in the rest of the system.  I also chose to install brass fittings and a brass PEX ball valve. These have slightly larger holes through them than the factory plastic fittings. So, the pickup holes have no affect on the flow rate compared to the stock pickup.  But if the holes were bigger, we could not get as much water out of the tank.  This was the only way I could think of that had a consistent pickup depth, could be installed in any tank and always end up with that same depth (with no measuring or possible installation error).  It is totally accessible and serviceable, even with the water tank full.  It does not affect the original pickup fitting, or the original tank drain piping.  And it ties into the existing piping at locations that are accessible, which makes the work much easier than it might have been.

 

If debris enters the tank at some point and clogs one of the pickup holes, it will still work well.  If more than one hole gets clogged and a restriction is noticed, the dip tube assembly can easily be removed, without draining the tank, cleaned and re-installed. You cannot do this with the stock pickup tube as originally built.

 

BTW,  any restriction that reduced the flow would put no extra load on the pump.  They are designed to run fine with a wide range of suction head pressures and they are just diaphragm pumps, which are very tolerant of flow restrictions. These pumps can run dry or at full pressure constantly without damage. They can draw from full or nearly empty tanks without damage.  The first thing you might notice with a clog is a reduced flow at the faucet with the pump running.  This is the same thing you might notice with a clogged aerator in the faucet, it's the same effect as when the faucet is only partially open.  Until my system started drawing air at about 6%, I could not detect a difference in the pump sound or the flow rate compared to before the modification.  Then it pumped the air and the water to varying ratios until the tank was pretty much empty.

 

This kind of  tank, with wide and shallow dimensions, requires a non standard kind of pickup.  It won't get every last drop, but I think it's the best we can do.  Having tanks of this shape is a real advantage because they take up so little room, are protected from freezing and are not outside where they could get damaged.  Fortunately, the corner of the tank and its piping are right there below the cover under the bed.  In the past, I wanted to do some work on the water tank in my Fleetwood, but found it was nearly impossible.  This is relatively easy and I was inside instead of underneath.  The biggest problem here is making the emotional leap of deciding you are going to make a hole in the tank and then spin welding on a fitting.  Once that hurdle is over it is just a matter of doing some PEX and fittings.  I think the future ones will have a larger tank fitting bushed down to the 3/4" dip tube assembly.  This will help with screwing the fittings together and give a larger hole to vacuum out the tank if needed.

[Overland]

Fantastic explanation. Thanks - if Oliver chooses to go with this then hopefully mine will be one of the first off the line to get your modification.

[bradbev]

Thanks John.  Good work!

 

I'd like to think mine would have the mod installed but I'm afraid it's not going to happen since next Monday is to be it's birth date.

 

Brad - Santa Fe, NM

[KarenLukens]

I always like to take enough time to think things through, and this morning was thinking that with the insertion of the new top port, that a normal gravity fill system would be really easy to add in also. The pump on the back is nice but slow with the 1/2" pex line. The normal 1" gravity port is about twice as fast as the pump. There's a couple places to install it, and I'm thinking that out the back would make it easy because you could just set the tank on the bumper and let it go. Mark had his Bigfoot here last week and we used my Simple Syphon Big Gulp system to gravity fill his tank. It only takes approximately 1 1/2 minutes to empty an 8 gallon container with the normal 1" gravity port...

 

But it's still in the thinking process :)

 

Reed

[Raspy]

Reed,

 

Now imagine that the new fitting I've shown has a TEE in it, between the tank and the top of the pickup.  In other words, the new pickup reaches down through a larger pipe with a TEE in it.  Off the side of that TEE is a line going to your gravity fill port.  This way, you could use the same tank fitting for both purposes, a dip tube and a tank fill.

 

I have ordered 1" fittings for the next installations.  This will allow room for the fill port, if desired, and a port big enough to get a small Vacuum hose into to clean the tank.

 

One fitting will allow for the new pickup, a clean out port and a gravity fill port if desired.

 

I did not think of a gravity fill port until you mentioned it, but it should integrate in well.

[bradbev]

Couple of thoughts from someone who hasn't received the Elite II yet:

 

The water tank has an existing penetration on top, the overflow/vent line.  I don't know how accessible that port is, but if it is accessible,  I'm wondering if it might be used as an entry port for a new suction line.

 

Second, my buddy's Bigfoot's black water tank had a leak/split on the top at the entry from the commode.  He used a plastic welding kit to not only repair the split, but he moved the opening closer to the wall giving more free floor space in his 25' Bigfoot's bathroom.  I had an identical Bigfoot but didn't tackle the project because I didn't have a leak, but I would have liked to have the commode moved a few inches closer to the wall.

 

I think you were using a process of spin welding?  I'm not familiar with that, but wondering if the plastic welding procedure might be an alternative.

 

Brad - Santa Fe, NM

[Raspy]

bradbev,

 

I don't know where the vent fitting is.  Only the rearward outer corner of fresh water tank is accessible.  That is where this new fitting is installed.

 

I originally thought I'd have to weld the fitting in a conventional way, and I wasn't looking forward to it because I had to reach down in so far and there are other heat sensitive things in the vicinity.  Then I decided to use spin welding and it solved the potential difficulty.  I think I included a link to the process earlier in this thread, or in KarenLukens blog.

 

It might be a good idea to ask Oliver what they plan to do with your Elite ll to fix the water problem, and then let us know what they say.

 

 

[KarenLukens]

Reed, Now imagine that the new fitting I’ve shown has a TEE in it, between the tank and the top of the pickup.

 

That's exactly what I was thinking but I haven't looked for a route out the back yet. I'll be filling up again in a couple days :)

[Try2Relax]

The water tank has an existing penetration on top, the overflow/vent line. I don’t know how accessible that port is, but if it is accessible, I’m wondering if it might be used as an entry port for a new suction line.

 

2 things - first, that physical tank port if pretty much completely inaccessible, it is located at the front corner of the kitchen drawers under the floor curve.

 

But that made me think

 

REED - my guess is that you will find your gravity fill design will take X-longer time to fill with the design you guys are going back and forth on, while the port is on top, the actual fill is located at the bottom of the tank, which means as it fills it will need to level the small fill tube with the entire tank, I would think once the tube holes are covered with water, it could take all day to equalize to fill and if your jug isn't water tight to the connection, then it will just start to come back out the fill tube once it can't equalize fast enough.

 

But as mentioned above, that vent line is a larger tube and actually feeds the to of the tank, if you remember I posted a picture of it's location in another post, you could cut it at is high point put in a T-valve and tap the gravity feed right there, then you could rig up an interior fill port on the counter right next to the sink or outside of desired.