I wonder.... if I had a hand pump with a realy long fill hose...and a guppy tank....and I froze the tank....and a large cooler filled with ice....and I hooked the pump's really long fill tube to the guppy tank with most of the really long fill hose coiled inside the large cooler full of ice.....I wonder.....
I got a little free air out of the deal. The guy admitted he accidentally filled my scuba to 4500psi too . The tank is working rated for 3500 but was designed/pressure tested for 5500 so guess I'm Ok.