Additional Freshwater Tank Install and pumps

[ClydesdaleKevin]

I finished the freshwater project for desert boondocking.  I call the new freshwater tank the Desert Tank.

I drove down to Ace for a few more fittings and male hose adapters for the Shurflo water transfer pump, tried a boat store and a trailer store for 1 1/4 ID vinyl hose for the water inlet but no luck, then finally found what I was looking for at Lowes and bought 2 feet of it.

Back to the RV and the project began in earnest.

From inside the compartment, I figured out where I wanted the water inlets to enter the compartment, and since I already measured and knew they would come up from somewhere under the bed, I drilled the two holes from below. 

I got lucky, and they came up at just the right spot for the length of the tank.

I decided to mount the tank on the driver's side, front to back, under the bed.  It will usually be empty, so I put it on the heavy side of the rig...short trips full of water won't matter.

I got really lucky with the water fill spout location on the tank as well...careful measurements and a hole saw later, and the filler is now located to the left upper corner of the lower fiberglass rear shell of the rig...right next to the upper left corner of the spare tire cover.  Its a direct slightly downward shot now to the water tank from the gravity filler...SWEET!

So once it was all lined up, I installed the outside gravity filler with 4 stainless screws, putty tape, and a bead of silicone.  I preattached the filler hose first, as well as the vent hose and hose clamps and fed them through the hole into the underbed compartment.  Lines up perfectly!

Then I connected the tank via a barb fitting and hose clamps, then band strapped it down.  Where the band strap came over the tank corners, I used the remainder of the vinyl hose, split down the middle, as cushions to keep the thin straps from wearing at and cutting into the polyethelyne tank.

The tank has 4 threaded 1/2 inch holes at its base.  The two under the filler neck I plugged with plugs and teflon tape.  I plugged these before banding the tank in place.

The two rears are for the water system itself.  One feeds down into the sewer compartment, hits an L fitting, then comes out a bit, hits another L fitting, then shoots down to a valve, then out to under the coach as a drain for when we want to drain the tank.  I used all CPVC fittings for this water routing since it was way cheaper, and its pretty durable stuff.

The other line comes down to an L, then comes out quite a bit further, hits another L, then down to a valve, another L, and terminates at the last CPVC glue in fitting, threaded with 1/2 inch pipe threads on the other side.  Everything up to this point was all CPVC glue type fittings.  Now, how to tie it into the PEX water system?  Flair-It fittings to the rescue!  A Flair-It with a half inch female side threaded onto the CPVC fitting, then a short piece of pex pipe, then that to a Flair-It T-fitting, which enters the pipe that goes to the new water pump.  Below that I added a Flair-It water shut off valve, in case I want to isolate one tank from another.  So the new freshwater tank is installed, plumbed in completely, and I zip tied the heck out of everything to keep it from moving much on the road.

Next it was time to add the male hose fittings to the old Shurflo water pump, to be used as a water transfer pump.  Easily done with short brass adapters, male hose threads on one side, and female 1/2" on the other, which threaded right onto the 1/2" 90s that are on the pump.  Quick and easy, and yellow plastic caps for each one, one marked IN and one marked OUT with Sharpee ink.

Okay, last part of the project.  I sacrificed a short drinking water hose we have on board, still in good shape.  Had to make the short hoses that will connect the pump to the city water inlet on the original freshwater tank, and another that will go into a jug so we can fill from jugs.  Decided to put a male adapter on the later hose after all, just so I could screw it together to keep it sealed when not in use.

Got that done, and THIS time decided to test the water transfer system, instead of getting out to the desert and finding out the cheapo Northern Tool pump barely worked!

A big pot of water, the inlet hose dipped into it, the outlet hose over it, and I hit the switch.  It worked!  The Shurflo self primed immediately and started pumping the water...SWEET!  So I added some bleach to the water to purify the hoses for storage, and ran the pump a while, then changed the water to clean water, ran it again, then one more time, then the hoses were removed, the fittings attached to each other to form two small sealed loops, and I stowed them away.  All cleaned, sanitized, and sealed for when we get out to the desert.

I'm still hanging on to the Northern Tool pump, which works fine as long as its below the water level being fed into it, and above or level to where its being fed too.  Might come in handy to transfer grey water sometime.

The following two pics show the pump setup.  The brand new pump is hanging on the sidewall of the compartment.  The old pump is the lower one.  I'll post more current pics when I have a chance.





Kev