I'm not sure I understand all this thread. I first thought it was about using an RV type pump like the Shurflo, which is a demand pump; i.e., the liquid flows through the pump and the pump cuts off when the outlet pressure reaches a certain level, usually 40 to 60 psi (although they make some for higher pressures) and comes on again when a faucet is opened to let the pressure out.
But now we're talking about air pressure pushing the fuel. A travel trailer I bought in '72 and a motorhome I bought in '73 had that arrangement. There was a 12 volt air compressor mounted to the floor with a 1/4" copper line running from the compressor or air pump into the top of the water tank. Those air pumps also had pressure switches. If I remember right, they came on at 20 psi and turned off at 40 psi. And the water tanks were cylindrical galvanized steel tanks. In the '60s and early '70s, that was a common RV water system. I didn't keep either of those RVs long enough to have a problem, but it was common for the tanks to rust out, and I don't know of any RVs using that system anymore. Everything I'm aware of went to plastic tanks to avoid rust and because the square shape allowed a larger water capacity in the same sized storage compartments, and of course, went to demand water pumps.