by 48Rob » Thu May 13, 2010 6:42 am
5' horizontally isn't too far.
Keeping the pump in the same general plane as the outlet on the tank will assure plenty of pressure to deliver the water from the tank, to the pump.
If mounted slightly higher than the outlet, you could have an issue when the tank is nearly empty and there isn't enough head pressure to push the water to the pump.
Most pumps actually are pretty good at drawing water up, vertically, though the higher they must draw, the less pressure you get at the tap.
Be sure you use a self priming pump if you don't mount it at or below the outlet level on the tank.
Some pumps are not designed to be run dry, and will quickly fail if mounted improperly.
In the average RV with an underfloor tank, 4 feet vertically is about the most the pump would have to raise the water, not enough to fuss over with any decent RV water pump that is designed to raise water 6-12 feet.
Short and sweet, research the pump you want to use, it will tell you how and where to mount it.
Rob
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...