High pressure "boost" pump

jwmorris · May 29, 2015

I have been interested in PCP air rifles since my daughter was born but didn't like the way folks have to fill them.

Built a pretty simple booster pump that uses 90 psi "shop" air and boosts my weld tank gasses up from 1500 psi up to the pressures they work at. 2400 psi so far, have to wait on the check valves and 4500 psi tank to get here for further testing.

CNC Dan · May 29, 2015

Looks good. Just be carefull with such high presssures.

Oh, and please turn your phone when taking video that is to go on youtube.

BHD · May 29, 2015

keep us updated, and post more details when done,

Thanks you for the post,

jwmorris · May 30, 2015

Check valves just came in.

bigdeano · May 30, 2015

That's pretty nifty. What did you use for a seal on the high pressure piston?

CNC Dan · May 30, 2015

jwmorris said:
Check valves just came in.

Wow. 4kpsi is a lot. Must be some good fittings to handle that kind of force. Did you have any leaks? What kind of tank are you filling, and does it fill fast enough to get hot? My LWS puts a fan on my argon tank when he fills it to 2kpsi. But it only takes a few minutes.
If it was slower, it might not get too hot.

jwmorris · May 30, 2015

Alli had on hand the right size were cheap harbor freight o-rings, I really didn't expect them to hold up to 4k psi.

I figured I would at least need a quad seal if not a cup seal, guess if the o-rings don't hold up I'll swap them out.

Brake line fittings so far, the tank is not here yet but it is a carbon fiber 4500 psi 68 cu tank.

SPIKER · May 31, 2015

Not one to push for safety police however those pressures of "gasses" are very dangerous. Fluids are nothing there as no expansion under a rupture but testing your welds and fittings with gasses is not a good plan. I have run fluids at excess of 60K PSI when working titanium lines & can say even an air bubble can cause explosive results.

at those working pressures single pas tig welds can/do fail & one on the chamber fitting looks somewhat suspect. Brass fittings also are not good in those pressure ranges under many standards and something picked up at local plumbing supply is not rated anywhere near those pressures. Specifically that brass coupling under the gauge appears to be a standard plumbing part w pipe threads most likely rated under 1200 psi.

CNC Dan · May 31, 2015

SPIKER said:
Not one to push for safety police however those pressures of "gasses" are very dangerous. Fluids are nothing there as no expansion under a rupture but testing your welds and fittings with gasses is not a good plan. I have run fluids at excess of 60K PSI when working titanium lines & can say even an air bubble can cause explosive results.

Gasses are fluids. I think you mean liquids.

jwmorris · May 31, 2015

Yes, testing hydraulically is always safer and good to go over operating pressures by a substantial amount for safety.

In any case the results are what they are.

Just for information and or ideas, attempt at your own risk, etc...