thanks very much pistone, the only experience i had until yesterday was a couple of fire extinguishers and learned my lesson early. i had four or five of the oxygen tanks that had pressure in them, once they started hissing i was gonna lay them to the side like i do extinguishers and let them leak out. on these tho i foundout pretty quick have an o-ring designed to burst once the valve is turned first time scared the .... outa me sounds like a 22 going off, anyway saftey glasses ffrom now on i think i got them all unless theres some more at the bottom of the boxes. im dont know what a hydraulic accumulator is but all the big tanks they gave me have holes in them that i have seen they just need to be cut in half, plus none of them are heavy enough to have fluid in them. i agree safety first, part of me wishes they all had the valves still on they are not as heavy as the extinguisher ones but they are heavy brass and probably over half a lb apiece