Portable tank on waist belt - What am I missing?

[essbend]

I'm new to PCPs, so I've been doing a lot of reading and trying to kludge together a workable system for me. Can any of you knowledgeable folk help me get this working as economically as possible?

Background:
After shopping around for an HPA tank I figured I could get a lot more use from it than to just fill PCPs: It could replace my 12V portable compressor, my bike pump, my paddle board inflator, and my shop compressor. The air tools I use don't require continuous air, so I figure the convenience of carrying an HPA tank rather than being tethered to a shop compressor would be worth having limited air. So I went ahead and got a 4500/150 PSI regulator.

The HPA tank I intend to carry is one of those small Ninja/Air Venturi/ Benjamin tanks, maybe 68ci capacity or so. It should be light enough to strap onto a waist belt with the regulator. I have a 88 cf SCBA for topping off the HPA tank.

The dive shop nearest to me charges $15 a fill to 4500 PSI, so I figure it'll be worth it to get a Chinese compressor like the Yong Heng. So I'll fill the SCBA with the Yong Heng and fill the HPA tank with the SCBA. Then I'll use the HPA to fill my PCP or connect it to the 150PSI regulator to run air tools. I attached a picture of my proposed setup.

Here are some questions I have:
If I used a fill adapter like the Ninja PCP fill station (sorry I can't post links) on an HPA tank, could I use it to fill the HPA from an SCBA? This way I wouldn't have to buy another fill station to fill the HPA from the SCBA. My concern is that there could be a one-way valve in the fill station, since some of the "paintball" PCP fill stations seem to be regulated down to 3000PSI output or less. I suspect I would have more luck with the Benjamin HPA, which looks like it uses a DIN valve without a regulator.

Also, I read somewhere that a water/oil separator on a compressor requires a minimum of 1800-2000 PSI while operating. Since I will be using the tanks for air tools, they will still be useful to me below 1000 PSI if I'm not trying to fill my PCP. Without a back-pressure regulator at the output of the water/oil separator, what are the consequences of filling the SCBA from say 1000 PSI? Will I just get a bit of extra moisture in my tank? Or does something bad happen to the filter media?

Steve

[Doug Wall]

If you're using a compressor to fill your SCBA, HPA, or gun, it will always pay to use both an oil/water separator AND a desiccant filter, on the output of the compressor. Any condensed water in the SCBA or HPA tanks will quite rapidly corrode the aluminum liners of the tanks. Don't worry about the pressure.

[essbend]

I ordered this filter from Ali Express:
]https://www.aliexpress.com/item/PCP-air-compressor-4500-psi-oil-water-filter-diving-seperator-300bar-30mpa-L350mm-OD49mm-ID36mm/32891898253.html?src=google&albslr=229532312&src=google&albch=shopping&acnt=708-803-3821&isdl=y&aff_short_key=UneMJZVf&albcp=1582410664&albag=59754279756&slnk=&trgt=296904914040&plac=&crea=en32891898253&netw=u&device=c&mtctp=&albbt=Google_7_shopping&aff_platform=google&gclid=EAIaIQobChMIidHr6Ib93QIVh0GGCh2mIQLwEAQYAiABEgKBgvD_BwE

It has compartments for using sieve, desiccant, or activated charcoal. I will probably get rid of the charcoal and use sieve in the first stage and desiccant in the second.

Also, I got some more info about the back pressure regulator. Nuvair has an adjustable one for $80:
]https://www.nuvair.com/1-4-npt-6000-psi-back-pressure-regulator-pressure-maintaining-valve.html
They say "The regulator will improve moisture separator efficiency and filter life as much as 450%." Apparently, having pressure in the filter is required for both efficiency and maintaining the life of the filter.

Also found that if I want to fill and deplete the HPA from the same port, I'll need one of these
]https://www.youtube.com/watch?v=ZlbKNZ55ipU
It's just like Ninja's 3000PSI HPA PCP fill stations, but it's unregulated.

I decided just to fill my PCP from my SCBA or the Yong Heng directly, and use a HPA for air tools only.

Whew I haven't done that much Googling since I first discovered internet porn...

[truck]

I don't think you'l have near enough air volume to run an air tool.

[T3PRanch]

Validation below:

http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1

I will be trying my home made version using a 1 hour SCBA tank and a Rohrer T-Post driver soon.

[truck]

Doesn't the t post driver require 2.5 cubic feet (4,320 cubic inches) of air per minute?

[chrisbee]

@truck, 2.5 cubic feet per minute sounds right for a t-post driver.  I read that a 60 minute scba cylinder at 4500psi. contains 88 cubic feet of air, so it should operate the driver for about a half an hour if my math is correct.  I think you could set a decent number of posts depending on how hard/rocky the soil is.  Just might be easier than sledging them in .  Creative thinking @T3PRanch, let us know how it works out for you when you get a chance.

[truck]

@truck, 2.5 cubic feet per minute sounds right for a t-post driver. I read that a 60 minute scba cylinder at 4500psi. contains 88 cubic feet of air, so it should operate the driver for about a half an hour if my math is correct.  I think you could set a decent number of posts depending on how hard/rocky the soil is.  Just might be easier than sledging them in .  Creative thinking @T3PRanch, let us know how it works out for you when you get a chance.

The old COMPRESSED air trick.

[essbend]

Validation below:

]url=http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1]http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1[/url]

I will be trying my home made version using a 1 hour SCBA tank and a Rohrer T-Post driver soon.

That's exactly what I was thinking. I got my 60 minute SCBA strapped to a fireman's harness running air tools, but it was pretty cumbersome. The 60 minute would be perfect for something like the T-Post driver, where you wouldn't have access to a compressor.

[tjsimmon]

Validation below:

]url=http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1]http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1[/url]

I will be trying my home made version using a 1 hour SCBA tank and a Rohrer T-Post driver soon.

That's exactly what I was thinking. I got my 60 minute SCBA strapped to a fireman's harness running air tools, but it was pretty cumbersome. The 60 minute would be perfect for something like the T-Post driver, where you wouldn't have access to a compressor.

What are you using to regulate from 4500psi down to the 80-120psi for most air tools?

[essbend]

Validation below:

]url=http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1]http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1[/url]

I will be trying my home made version using a 1 hour SCBA tank and a Rohrer T-Post driver soon.

This:
]https://www.ebay.com/itm/New-Tescom-High-Pressure-316-Stainless-Regulator-6000-PSI-150-PSI-26-1561-24/183309947571?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
That's exactly what I was thinking. I got my 60 minute SCBA strapped to a fireman's harness running air tools, but it was pretty cumbersome. The 60 minute would be perfect for something like the T-Post driver, where you wouldn't have access to a compressor.

What are you using to regulate from 4500psi down to the 80-120psi for most air tools?

[essbend]

Validation below:

]url=http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1]http://komptec.com/us/index.php?main_page=product_info&cPath=1&products_id=1[/url]

I will be trying my home made version using a 1 hour SCBA tank and a Rohrer T-Post driver soon.

That's exactly what I was thinking. I got my 60 minute SCBA strapped to a fireman's harness running air tools, but it was pretty cumbersome. The 60 minute would be perfect for something like the T-Post driver, where you wouldn't have access to a compressor.

What are you using to regulate from 4500psi down to the 80-120psi for most air tools?

This:
]https://www.ebay.com/itm/New-Tescom-High-Pressure-316-Stainless-Regulator-6000-PSI-150-PSI-26-1561-24/183309947571?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

[Doug Wall]

"It has compartments for using sieve, desiccant, or activated charcoal. I will probably get rid of the charcoal and use sieve in the first stage and desiccant in the second."

Molecular sieve IS the desiccant! Remember, the molecular sieve doesn't have unlimited life. You should probably re-dry it to specs after every 88 cuft fill.

Also, I note that the regulator that you show has 1/4" npt input and output. PLEASE make sure that all of your fittings are rated for at least 4500 psi. This is not likely something that you'll find in your local hardware store.

[essbend]

That's good advice.

I meant silica gel when I said desiccant. For now, I'll stick with whatever comes with the purchase.

Any idea how I can re-dry the sieve? I have an oven, but I'm not sure it will get hot enough.

Yes I have all 4500 or 6000 PSI rated fittings on the high-pressure side and "hardware store" fittings on the low-pressure side. I was considering putting all the part number on a bill of materials to calculate the total cost of everything, but I'm no glutton for pain.