On Board Air Pressure Tank

[duffer]

I've been using an aluminum O2 tank for my York OBA for 7 or 8 years. Seems to me it was rated at something like 3000 psi. In my flatty, it was a bit too long to plumb the inlet fitting it between the frame rails so I machined the neck down about 1/2". That still left a good inch of material there. I also drilled and tapped it for a 1/4 NPT drain. Again, way more than ample wall thickness for an air system. My tank is also installed against the bed in front of the rear axle. At first I used one of Grainger's cable release drains on it but that was still a bit awkward. Then the Surplus Center had a bunch of GM diesel fuel shut off solenoid valves for cheap-they work perfect. I did add a stainless steel sintered filter on the outlet to keep any grit out of that valve.


As a bonus, you get to scare the Bgezzus out of unsuspecting people walking around your rig.

 

[Lumpy Grits]

well i speak from experience of lugging an O2 tank around on the ambulance fro 16 years.

I was speaking from 'dragging' dive tanks around the world for the better part of 40 yrs.
02 Welding tanks, run 2K+ psi all the time.
You should see what the carbon fiber tanks can hold in PSI-
Thank you for your service in helping others!
LG

 

[Hedgehog]

Duffer - I believe I've got this right, you didn't weld on a bung, you just drilled and tapped the sides. Seems logical enough and for aluminum the tank certainly had a substantial enough feel to it so it wouldn't surprise me to have very thick walls. If this is the case then there is no reason not to get the tank ..... besides it looks really cool.

This is yet another one of those projects that have hung around far to long.

Lumpy - Where did you get the hose attachment part that attaches to the AC compressor? That is what is held me back, getting those fittings to start. They are available at ... ???? .... I can't remember the companies name, there is a link here somewhere .... the guy specializes in converting AC compressors to onboard air systems. Some of his parts are a little pricey, like $45.00 for the fittings I'm talking about. it is simply a situation of needing to get off the pot and start.

 

[duffer]

Which compressor? There are three different heads on the Yorks. If it is the Rotoloc version, Kilby is the only place I know to get those. I did use one of their fittings on the output but just made the rest of the system using mostly Grainger sourced parts.

 

[duffer]

Yep, no bung, just drilled and taped. Wall is someplace around 3/8's to 1/2".

Here is a list of most items I used, originally posted over at ECJ5. The only Kilby part was a 90 degree Rotolock fitting and most hardware items were sourced through Grainger.

Compressor: York Model 000168, SN: AMC-5461585. Application: 1984 Jeep Wagoneer. 10.3 cu in displacement. Front seal kit: J8120180. Pump manufactured by Borg Warner.

Head output fitting: Kilby 4470 Rotolock to 1/2 NPT 90 degree elbow.

Manifold: Custom machined 6063 aluminum 12 port.

Safety Valve: Control Devices SA25-AMC 150 , Grainger item 5A713, ¼ NPT male thread, AMC 150 psi.

Air Filter: Solberg FS-15-075, modified with custom machined rotolock fitting for direct connection to compressor head threaded suction port. Grainger item 4Z679.

Air Line Filter/Separator: Speedaire 4ZL42, metal with ½ inch NPT connections.

Check Valve/Unloader: Control Devices “Load Genie” PA241A, Grainger item 5A705, ½ inch NPTfemale inlet, ½ inch male outlet.

Pressure Switch: Square D 9013FHG 19J27. 70 - 100 psi factory setting, fixed 30 psi differential. Grainger item 2FG82. ¼ inch male NPT connection. Run it set at 145 psi max.

Air Tank: Linde aluminum medical oxygen tank mounted transverse just ahead of rear axle against bed.

Quick Connects: PCC Series F, 303 stainless steel, ¼ inch female NPT connection. Industrial interchange style (same as Milton M).

While perhaps not necessary, I really like the flexibility of having an adjustable pressure switch.

What it looks like.

 

[Hedgehog]

Thanks a ton for the direct input especially the part numbers, sounds like a trip to Grainger is in order. ........ On another subject, darn, your jeeps looks so nice it just seems wrong! Very nice, the whole thing looks so nice the grey pressure regulator box looks cheap and out of place. ... very nice indeed.

 

[Lumpy Grits]

Hedge-The blue fitting?? It's an AN fitting for connection of aircraft hydraulic lines.
The other fittings are the OEM for the compressor.
The A/C and mount, came from a junkyard.
The blue hose is DOT air brake hose.
LG

 

[Lumpy Grits]

Duffer-Did you do all that work?
VERY NICE!
Any chance we could see a picture or 2 of the tank??
LG

 

[duffer]

A few of the home brewed pieces.

Breather assembly.




Cap on that provides an air lock so unless it's wheels up, shouldn't allow any water access.

Air cleaner/mounting. Used the original Rotolock nut (center)




Do you actually need that big of air cleaner? No, but like an engine, the less flow resistance, the better the efficiency. The drain on the filter is also configured so you can dump any water collected and then return the separated oil back to the compressor. And if you do use an unloader (not necessary but will make the clutch last longer), it will waterproof the engine bay without some sort of sleeve to redirect that unloaded air.

 

[duffer]

Duffer-Did you do all that work?
VERY NICE!
Any chance we could see a picture or 2 of the tank??
LG

I thought I had a couple of bad photos of the air tank but can't find them. Will look some more later.

And until a couple weeks back, I could have said I did ALL the work. I finally had one of the local 4x4 shops set up the ARB/new gears in the front axle. Figured by the time I pressed on and removed the bearings a half dozen times with no set-up bearings, I would be buying another bearing set and just wasn't worth it. Outside of that, no one else gets to wrench on the B.

 

[Lumpy Grits]

Very nice workmanship.
I've been set'n R&Ps for the best part of 50 years, and every now and then get a set that just doesn't want to 'come-together'.
Most of the time, it's a warped carrier--

LG

 

[johnnyreb]

Thank you for your service in helping others!
LG[/QUOTE]

Thanks Lumpy. It's certainly a calling.

 

[Hedgehog]

After looking at the workmanship of Duffer's jeep He sold me on getting the tank, after all if a medical O2 tank is good enough for somebody with Duffers standards there is no reason it won't work for a relative hacker like me.

Duffer, man I'm still impressed with your set up. Mine is fairly clean, but nothing like yours. Mine is more like Lumpy's practicality first set up than your aircraft/NASCAR worthy system.

 

[Torxhead]

Hedge, adding an air tank really worked out for me. I do get a bit of oil past my separator. So when I plumbed the tank, I had the air going in one end and the air outlet on the other side. This way the oil and water stays in the tank and is drained out thru the drain at the bottom. A recent tire change showed no oil on the inside of the tire.

 

[AeroMoto]

nd if you do use an unloader (not necessary but will make the clutch last longer), it will waterproof the engine bay without some sort of sleeve to redirect that unloaded air.

What is an unloader? I'm guessing it drains all the air out of the tank when you cut off the Jeep?

 

[johnnyreb]

if it's like a regular air compressor then it should be a check valve between the tank and pump. That way when it starts pumping, you don't have all the tank pressure to over come.

 

[Lumpy Grits]

What is an unloader? I'm guessing it drains all the air out of the tank when you cut off the Jeep?

Also known as a 'relief-valve'
LG

 

[Hedgehog]

Not exactly a relief valve per say. It's more of a check valve. The unloader does exactly what it's name says, it unloads or bleeds off the air between the pump and well, other pump related stuff. It allows the pump to start without an air pressure load on the pump.

 

[duffer]

Not exactly a relief valve per say. It's more of a check valve. The unloader does exactly what it's name says, it unloads or bleeds off the air between the pump and well, other pump related stuff. It allows the pump to start without an air pressure load on the pump.

Yep, maintains pressure in the system but releases it from the compressor so when it starts, it does so without any loading. In my photo, it is the brass fitting with the cylindrical aluminum sleeve between the York and the separator. There is a drain line below the sleeve you can just make out if you squint a bit. Exactly the same setup as used on a typical shop compressor.

 

[Hedgehog]

I'm not so sure an unloader is at all necessary. A normal AC system runs at far higher pressures than the relatively small pressures in a AMC 150 lb OBA system. Everytime a normal AC unit starts the load is FAR higher than we are talking about so the relative wear on the clutch is small in comparison. I think I'm going to lean toward a normal air valve to shut the tank off so it holds pressure for maintenance and such. I suppose that would be bad though. What happens if I should forget to turn the valve back on and turn on the compressor .... well the pop off valve would pop and scare me to death with no real harm done. Hmmmm, maybe a check valve would be better.