It definitely liquefies under pressures needed to fill these cylinders. I don't have a regulator here, but exit pressures are around 900psi unregulated.

I was using it straight from the bottle unregulated to flush a bunch of iron sediment out of a 300' long loop of 1-1/2 and 2" hot water lines after I rehabbed and put back into service a 70 year old hot water storage tank. The tank had a bunch of tubercule buildup and ended up in the return line, killing pressure.

Incidentally during this visit I fried a 6,000 dollar variable frequency drive for the air handler when I got a slug of water to shoot out of the cut open plumbing about 10' across a room and hose down the unprotected VFD.

Whoops.