Quote Originally Posted by Biker_Bob View Post
You dont' need a check valve - the pump should have one built in.
I used to fill a Gunpower Stealth bottle with a pump and also a best fittings 500cc field bottle neither of which have their own check valve - it was physically hard work but it was possible.

A few observations - it is extremely hard work on the pump and it will generate a lot of heat and moisture. If you do manage to fill the cylinder I think the pump will probably be ruined by the end. You will need to take frequent breaks to let the pump cool down, in reality I think it would probably take a day to fill the cylinder, with rests for you and the pump.

Pumping over 200 bar is much harder than pumping up to 200 bar.

Without blowing my own trumpet I am extremely fit and quite large and strong and filling the 500cc cylinder to 250bar used to make me puff and sweat some and I had to take rest breaks to get the cylinder filled. I really think that you're on a hiding to nothing with this one.
you may be right, but if theres even a chance, i would like to try it...
in theory [if the pump has a check valve like you say] all i would need is a lump of ally or brass with 2 holes drilled next to each other [probe size holes] so that i can fit the pump probe in one, the bottle probe in the other... and a smaller hole at 90 degrees joining the 2 holes [centrally ie between the o-rings of the probes] and then block off the holes entrance........ should be quite easy to make without any fancy tools maybe ?