We don't use the water straight from the city hookup in the campground. The water filters we use knock the gpms down so much it's sad. But the water pump puts out 3.5 gpm. Triple the water flow once it goes thru the filters. So we pump all our water from our fresh water holding tank.
David & I are lazy. Not the "never getting up off the couch" lazy but the "why make more work when you don't have to" type of lazy. One of the things that has bugged us about the Class C was filling the fresh water tank. Because we would start filling the tank and get side tracked doing something else and forget... until we noticed the huge puddle. It is not a situation exclusive to us.
These folks flooded the campground in Socorro. I think it ran all night.
So we decided to put a Float Valve in the fresh water tank. You are all familiar with float valves. Look inside any residential toilet and you will see a float valve at work. The one we used came from a feed & livestock supply store. It was rated as "Potable" water and sold to be used in livestock watering tanks. We bought one that hooked up to the 1/2" PEX that is run thru out the bus. What allows us to do this tank modification is the fact that we used an ABS water tank rather than the standard translucent (so you can see the water level) polyethylene tanks normally sold as fresh water tanks. With the float valve, the water will fill the tank until the float closes the valve. When the water level drops below a certain point, the valve will open allowing water in. So we don't have to babysit the tanks while they fill.
Our tank fills slowly. We have a sediment filter plus a 0.5 micron water filter on our system. The 0.5 micron filter drops our water flow down to 1 gpm. That's not too great. Our Shurflo 2088 water pump pumps at 3.5 gpm (yes that's right, I just checked before I typed it). That is enough to give a very nice shower with a non-water saver shower head. I also emptied the 30 gallon tank really fast. David drilled a 1/8" hole in a penny to use as a flow reducer in the shower head. Now the water lasts as long as my shower and then some. AND WE NEVER HAVE TO GO REMEMBER TO FILL THE WATER TANK!
We did discover a problem that was easily fixed. When the water level dropped (usually due to a shower) sometimes the float would hang in the open position (hanging straight down) and the water wouldn't lift it back up. We think this is because the float is designed to be installed in more than one position. So we made an easy fix. We placed a length of plastic plumbers strap in the tank and secured it to the opening. This also gives support to the float if the water level is low and we are traveling down the road.
We used a piece of FRP as a cover for the access hole that we cut into the Valterra ABS tank. It is secured in place with screws and butyl tape.
This is a view of the interior of the tank showing the valve going thru the thick end of the tank. David just drilled a hole the size the valve needed and threaded it thru. The valve came with all the bulkhead fittings needed to create a leak free install. We did have to allow for the tank float ball (hold fitting down so that float ball just touched the top of the tank and still closed the valve) and in doing so lost a little bit of water storage.
The plumbers strap was installed with enough slack to allow the valve to open to fill but still support the float and prevent it from dropping all the way down.
This is the "overflow" that we no longer need as an overflow. Our tank no longer overflows! It also allows the air to enter and escape as needed. That, we do need.
This is the line from the tank to the water pump inside the bus.
The white fitting is the float valve. The fitting on the lower right hand corner is a plug. This will be removed when I get the second tank to install. This is a reused tank. We had to use it on our way out west to build a misting system for the radiator. Everyone hauls a never been used 30 gallon tank, a 12vDC water pump and a garden misting system around with them just for situations like that?
Anyway, the tank has only had potable water in it.
Screwing the cover on and securing the strap at the same time.
The tank we are currently using is a 30 gallon Valterra ABS tank. According to measurements plugged into the tank calculator
For a rectangular tank 30" long X 14" High (water height when valve closes) X 8" wide = 29 gallons. So we lose a gallon for our particular tank set up. Adding a second tank will mean that the water will level out the same as the float valve tank. This will give us 58 gallons of fresh water while parked. When traveling, we will install a shut off valve to close down the second tank. This will allow us to run only the float tank full of water. To empty the second tank, we will either drain the tank with another shut off valve or turn the incoming water off, run the tanks dry, close down the second tank and turn the water back on to fill the float tank. If we know we will be traveling (in other words , not an emergency run) we will shut the water off a day or two ahead, use up the water, close the tank, turn water back on. If it's an emergency then it may be a good idea to have both tanks full. The extra tank of water isn't going to make that much difference in the mpgs.
As for why we need 58 gallons of water? With this setup, 30 gallons is fine filling at 1 gpm for showers and handwashing dishes. But add a washing machine and an automatic dishwasher to the mix and I am concerned about how long it takes the water tank to recover. Plus we have been out of water (burst city pipes) enough times to know that it doesn't get fixed real fast.
This is a real time saver and we never have to worry about not having water in the tank.
can be glued with all-purpose pipe glue, you can glue PVC pipe fittings into the tank using the all-purpose glue And they can be repaired using the all purpose pipe cement or you can "melt" abs shavings in MEK. I've bought ABS tent stakes in Wal-Mart to shave and melt. I've used all of these methods to repair ABS
. I'll take ABS over polyethelyne any day.