Plumbing - Laying the hot and cold water piping
So next on the big list on things to do is the plumbing prep - this essentially is two loops around the van providing hot and cold water. So we start from the water tank.
I had made a custom sized water tank holding 113l of water - this is FAR too much water! 1l is the same as 1kg so that's a large sized tiger now weighing down the rear end. I have been using the water on one of the vans recent trips and you don't need that much at all - a quatre of that size will get you by fine, but to be comfortable i would say 50l is plenty. I only have to drain the thing when i go on journeys anyway as too much water increases fuel consumption too. Most campsite and service stations have fresh water taps everywhere to refill.
In any case this tank i mounted in the rear of the van along one wall. I made sure to position it over the rear axle to make sure any weight from the wate is loaded carefully across a weight bearing structure. I then made a wood frame to support it and also which later became part of the rear storage area. I secured the wood to the van frame and the water tank to the wood frame. This is a heavy object even half loaded so it must be securely fixed. I used extra wide timbre and bolted as well as screwed the bits together. More screws the better!
I also added a volume sensor to send the data to the central control panel so i can keep an eye on all the weights and volumes in the van. I then fed the hot and cold water pipes around the van to feed all of the services. I tried to keep this to one nice loop starting at the cold water tank going across to the hot water heater tank under the sofa. I then returned backwards to supply the shower cold water and then returned to the rear of the van with the cold water supplying the toilet flush and bathroom sink along the way. The rear of the van needs a supply for the outside shower system connector. I then did the same for the hot water pipes except i started at the hot water tank and ended at the fresh water tank side (as the kitchen sink is next to to this and needs a supply too).
Where possible i hid the pipe in the walls of the van to keep the profile down to a minimum. I also wrapped all of the hot water pipe in insulating foam to keep it warm for longer. The cold is not a problem as all the pipes are inside the van and shouldn't freeze as i have insulated the walls of the van well.
Now that the pipes are all laid i added the fresh water pump which is just a 40psi diaphragm pump with a strainer attached to it to catch and loose debris. This connect directly below the fresh water tank which is sitting about a foot off the deck on wooden supports. When i designed the tank i put the outlet holes in the specific places i wanted to access the tank. I also placed two holes on the top of the tank one for gas release to let the water come out the bottom and one for filling the tank. The pump is an auto on off pump so you can turn it on and leave it. It will turn on and self prime when the pressure starts to get low. I also added a water pressure expansion tank accumulator this is just a tank which is pressurised in itself and stops the water pump turning on off in quick succession like you sometimes see on caravans along with a loud noise and lots of vibrations!
To make the system safe i added some water stop valves in case there is a leak i can isolate the hot water from the water tank and also the cold water. I can also drain down the system this way too. The way this is done is through the heating system. There is a valve in there which drains the water to the ground through a hole in the van this prevents freezing and assists in cleaning the system too.