So its now looking like we may be fitting one of the 4 hole toroidal under slung 55ltr LPG tanks. The main reason we have decided to go this way is that the cylindrical tanks are of such a diameter as they hang significantly lower than the chassis members and so have no protection. Has anyone any experience of such tanks that they'd like to recount, good or bad? In addition we are also looking to use a solenoid valve as a means of isolation on the outlet to the tank as is fitted to most road fuel tanks rather than the manual valves usually fitted to under slung tanks. It's ten quid more plus the buggery factor of wiring it in but feels like it would be much more convenient ! Any thoughts, for or against please?