What work did you just do?

[Gippeto]

 

[chongman]

Hmmmm... going to have to think on this one a bit...

[quickster47 †]

Looks to me like it has the makings of an air regulator for filling tanks.

Carl

[BDS]

Whatever it is... it's H.P. for sure!

[Gippeto]

Booster pump...will allow full fills from as little as 100psi in a scuba/scba tank. Bit bigger than some variants, should be able to fill tanks if I automate it. Looks a little easier than a stirrup pump hmm?

Finished the check valve pieces this morning...assembly over lunch break.

The inspiration;

[youtube]https://www.youtube.com/watch?v=Kc8RfkDSbfE#ws]Aircraft Maintenance - Bogert Aviation Aircraft 30x Strut Pump Tool[/url]

Al

[BDS]

Nice Gippetto, proves there is (almost) nothing new under the sun eh? I remember using booster pumps when doing hydro-tets on pressure casings. It would sit there and cycle until we reached the burst test pressure. Similar idea, a contained bellows/diaphram of some type?

[Gippeto]

No..nothing new, just re discovered and re purposed.

Using a service brake chamber for a big rig....same as in the video. Took notice because I recognized what it was from an air brake course.

Al

[BDS]

Cool beans... 

[Gippeto]

Might as well bring this right up to date...I finished up a couple bits this morning, assembled over lunch and had a quick test.



Works quite well actually. Was feeding the hp end 90 psi and cycling by sticking the air hose to the diaphragm. More testing to come after I get the stand made. Four pump strokes had the fittings, gauge and dead space filled to 3000psi...gauge was climbing good when I terminated the test mid stroke.

[quickster47 †]

Gippeto that is way cool.  Great job.

Carl

[chongman]

This be some serious stuff!

[targettgii]

Very cool Gippeto.

[JEBert]

I like it!
I'm curious to see how you automate the cycling process.
Cheers,

[BDS]

Gippeto... what's your thoughts on direct fills to a rifle or pistol? Is there enough volume to make this a 5 min fill? 10 mins? How about the fill time on the SCBA tanks?

In the video (the red machine) there is a bypass? tube from the 100 psi inlet around to a manifold and the HP outlet, what does that do?

It's been a long time since I used the similar device for hydro-testing (air over water) but, I seem to recall being able to set the output pressure and then apply the inlet pressure (shop air) and just let the pump cycle until it reached set point. It would cycle very quickly for a few minutes with it slowly decreasing as it neared the set point. Wish I knew how that was done, my grey matter memory disc cant find that "file" ha ha.

[Gippeto]

Thanks fellas....I'm stoked to start testing it...and using it too.

The line running around to the hp end is feeding the hp end with 100psi...precharging the cylinder.

Cylinder volume is 38.6cc charged to 100psi...3860cc*psi. A 250cc reservoir from empty to 2900psi (200bar) is 725000cc*psi.(keeping it simple here...)

72500/3860 = 187.8 strokes of the pump. At one stroke every two seconds (might be faster, I don't know yet) that works out to 376 seconds... ~6 minutes 20 seconds.

If it were a top off situation from 100bar to 200bar, this would reduce to ~123 strokes...just over 4 minutes.

If you can feed the hp end a higher pressure, fill times will be reduced.

1000 psi into the hp end would charge the cylinder to 1000psi (will bleed past the checks until pressure equalizes) and require 12.3 strokes to top off the reservoir to 200bar. This is where such a device truly shines...getting full fills from a scuba/scba/N2 bottle even when they run down.

This is @ 100% efficiency...while efforts were made to maintain efficiency, it won't be 100%....testing needs to be done.

Adding a regulator to the diaphragm end will allow the pump to simply stall once the forces balance. Outlet pressure can be set in such a manner.

Al