got a few vans with 450 and 650 tanks which are safely strapped and bolted down. however im either buying a 125 or 250 tank to put in a small van for a part time worker as he will be doing a few hours a day to tie in with a courier part time job. can any1 tell me is it safe to not strap a small tank down if so what is minimum size tank which is ok to not have strapped and bolted down? and would water pressure/flow be better from an upright tank or flat tank? or will it be the same and the pump what does the work?