Well, I got most of the plumbing done today. I wanted to be able to select between using an external water source and the water tank. To do this, you can get a two way valve (often called an L port valve). Just sticking in an L port valve is not enough as you could contaminate your drinking water so you need to use some check valves. They only let water flow one way so there is no chance of any cross contamination when you switch the valve over. So here is a smaller version of what the council wanted when they connnected town water to a house I owned once which was just on rain water:
Believe it or not, you are looking at about $90 worth of fittings. The shiny round fittings are the check valves.
The two tails pointing to the right are the inlets. One for the tank and one for the existing shower inlet I already had. The other goes to the tank. The tail pointing to the bottom ofthe pic is the outlet that goes to my pressure pump. So where to fit it? There looked like to be a good place just under the right hand side headight that would be easy for me to reach the valve. I used a couple of copper saddles to hold the fittings on. I have found the box of self-drilling galvanised roofing screws I had left over from building my shed to be great for mounting this sort of stuff.
It really would have been better if I had bought another brass elbow for the bottom tail so it also pointed to the right as well. No matter, I just used a low density poly irrigation elbow:
Some people reckon plastic fittings are the way to go on a verhicle as they are nice and light and thus stand up to vibrations well.
The white hose is certified drinking water hose so there should be no taints in the water.
You need to explore this thread a bit to find pics of the Shurflo pressure pump fitted in the engine bay.The hose from the water tank runs along the outside of the chassis rail to keep it away from the heat of the exhaust.
This shows where the pipe comes down in front of the rear wheel.
I decided to put a T piece in here and run a pipe back to a tap at the rear of the car so I could gravitate water out of the tank if the pump stuffs up or the battery is flat.
It is easy to get pipes back behind the rear wheel as you can push them over the top of the plastic inner guard.
So this is where I decided to mount the tap.
The tap handle is tucked right in behind a cross member so it should not get knocked open.
Just for now, I just added a short piece of hose to the tap for testing:
Anyway normally I would remove this hose to keep it clean and only fit it if ever it is required.
I still have to Tee into the outlet side and run a line back to the tub for cooking but I have not quite sorted out how I want to do and it may need to wait until I put in my drawer unit.
I filled the tank and ran it all out through the shower to test for leaks and give it a good flush. Took 21 minutes to empty the tank, so that should be a pretty good shower
I will never be going that far. Looks like I better grab my camera and take a pic of my latest mod. Nothing to do with PC's 
