AIr compressor question

[Ricklin]

Read through this forum category and only found a couple mentions of what I am considering. I have 100 PSI instrument quality air online in my shop currently. I'm a retired dental equipment guy thus my compressor is a dental compressed air system with excellent filtration and drying. The unit has desiccant drying, very low dewpoint air is produced, about -150 F dewpoint.
I see the intake on my new 4500 PSI 30 bar compressor is 1/4 NPT. My thought is to plumb the intake of the HPA compressor to the output of my shop compressor. So regulate the source air to the 1/4 NPT port to ballpark atmospheric pressure? I'm thinking 10-15 PSI regulated input.

 

[scubajeeper]

I don’t see a problem with that but to be safe I’d contact the manufacturer of the HPA compressor

 

[Firewalker]

Yupper, no problems, don't overwhelm the intake.

 

[Ricklin]

Thanks guys. Might shoot an email to the seller, if typical they will not have a clue, IF a response is received. not in the mood to make a video. Thanks Firewalker, I'm very familiar with lower pressure systems having sold and repaired dental compressor systems for decades. I'll start with just a simple male NPT airline QD for a 5/16" 10 PSI or so direct connection from the shop compressor, I've a big high flow regulator on it for my HVLP spray gun. Should be plenty of flow of super dry filtered air feeding the HPA pump. I figure as long as I don't load the piston when starting, it should be happy. I'm of course beginning with the end in mind yet doing my best to apply KISS. Perhaps feeding the Yong Heng clone with super dry clean feed air helps longevity. I shall update once it is happily pumping air.....or not. Once that truck shows up my PCP journey begins. It does seem like I found a great forum so far.

 

[bchannell]

Shouldn't be a problem at all. I feed nitrogen to my GX compressor at a rate of 9 psi all the time. No moisture and it helps fill very slightly faster. I've been doing it for quite a while now and no problems.
What you're thinking of doing is virtually the same thing. I've never felt the need to go over about 10 psi, and you can sort of tell when the compressor labors a bit from the inlet pressure. So for me, I wouldn't go over 10 psi.

 

[BlackICE]

Worst case boosting the input pressure will increase the load on the motor at full output pressure at least in proportion. i.e. Boost the input to 14.7 psi the motor has to output twice the power as before. Not a good thing to try. I have a GS4 and measured the power use of the AC/DC adapter pumping to a full 350 bar. I used that number as the topline safe power use. Then I boosted the input pressure and found the same power use while pump to only 300 bar at 4 psi input. That's what I use so I don't overload the system any more than it was designed for.

You can boost more at low output pressure while reducing the boost as the output pressure rises. Very useful for filling empty tanks or guns. Just monitor the power consumption.

 

[Ricklin]

Since this little guy is 100% manual, it's pretty much a babysitting gig anyhow. Once I know the pump up times that I will need I may incorporate a simple wind up timer as a last ditch safety valve since it will keep on truckin to 4500 if I do not intervene.. I found a nice little sturdy cooler just the right size to set the pump on top, will make a good water tank. I'll watch that infeed air PSI and start out with 9-10 PSI from my system. I am screwing things together as we speak, really impressed with the big gold anodized filter with Fosters at each end, wow it's like the pump is free with this goodie. Lots of spare burst discs and O-rings as well. Packed really well, not a scratch and even comes with cotton gloves. TIme to get some oil in it and fire it up. I'll throw an amp clamp on for testing. The boosting more at low pressure thing was something I considered, let the big guy get us up to 100 anyway, it's very good at that. I am having fun now.

 

[Ricklin]

Thanks again for the tip on low input pressure, works great but 15 PSI was too great a starting load, backed it down to under 10 and it's all good. I put the original intake filter on another female air line QD fitting, that way it gets filtered air if using away from my shop air. I am direct filling the little reservoir on the Beeman 2028, takes less than one minute. I need an SCBA tank soon. But my next purchase will be the Hatsan Blitz in .22. I made a little extra money lately, the toy fund balance can soon support the purchase. I shall report back from full auto happy land. A couple of the extended magazines will arrive with it.