Rigging an OnBoard Air setup - now installed and with pics

[shorty_f0rty]

Hey all,

have been doing a bit of research on the OBA thing and i'm just about ready eg, in the way of tank, bits and peices and decomissioning the A/C. But before I commit to this I like to be able to see what it is im doing and where its all hooking up. So this is where I thought it might be a good idea to sketch out how my particular setup is going to be rigged up.

now from the research i have done i have picked up that if your not gonna tap into your A/c to oil it, then you'll need a inline oiler (will the ones used for airtools be sufficient for the A/C comp?) and an air filter on the intake. then an inline filter on the output. alot of setups talk about a check value, pressure swithc and safety valve at teh compressor end of the system.

now heres where i tend to get a bit vague and unsure. when i went to enzed with my tank they gave me a one way valve for the tank intake, along with drain,safety valve, T connector and a few quick connects. This gear leads me to believe that I should be right without a check valve on the A/C comp output and the pressure switch should belong on the output of the tank.

if this assumption is correct than that means i dont need to find room in the engine bay for all that crap and only really need an inline filter for the A/C output.

also, if i didnt put an inline filter on the A/C output, and the oil from the comp made it into the tank.. would there bee enough pressure for the oil to make it out to the air hose and be enough to lube airtools? I realise I would need a line with an inline filter so I dont fill my tyres with crud.

I have attached a few images for clarity. The first is what I interpret as a pretty common setup with the York compressor (and most common setups found during my research). The second is what I think should work (in theory) if all the bits i have do what I think they do.

I was hoping it should be easy enough to tap into the existing A/C switch to enable the pressure switch when the ignitions on.

Id appreciate any suggestions feedback. before you suggest tapping the A/C, id really prefer not to as its all hooked up and would be a PITA.

Thanks!

[dumbdunce]

if you can find an inline piston type compressor instead of the swash-plate type you have illustrated, they have an integral sump and do not need oiling on the input line. you can recognise these compressors as they have a more square/rectangular body, the swash-plate type are round bodied.

for your 'desired' setup with a regular, round bodied compressor you need to add an oil/air separator on the compressor outlet or you will eventually fill your tank with oil, that's no good.

otherwise looks prety good.

cheers

Brian

[shorty_f0rty]

if you can find an inline piston type compressor instead of the swash-plate type you have illustrated, they have an integral sump and do not need oiling on the input line. you can recognise these compressors as they have a more square/rectangular body, the swash-plate type are round bodied.

Yes that would of been my first choice if i didnt already have an stock A/C compressor thats not being used for A/C. I prefer to use my existing one to save on having to fab brakets, etc, etc so thats why I'm thinking of sticking to the setup above. The inline filter on the output of the compressor is what I was thinking would seperate the air/oil but I probably found the wrong "inline filter".

Thanks for your feedback though Brian.

[dumbdunce]

if you can find an inline piston type compressor...

Yes that would of been my first choice if i didnt already have an stock A/C compressor thats not being used for A/C. I prefer to use my existing one to save on having to fab brakets, etc, etc so thats why I'm thinking of sticking to the setup above.

fair enough, oiling up the existing is always goiing to be easier than building stuff.

The inline filter on the output of the compressor is what I was thinking would seperate the air/oil but I probably found the wrong "inline filter".

I think filters just filter, filter/separator is what you need but not a big deal, you can get them for supercheap or bunnings.

I am jealous, I have never had space for a compressor (all my 4WDs always had air conditioning )

[berazafi]

Ok a couple of things I would be looking at, if possible I would put the pressure switch as close as possible to the pump, just in case you get a blocked line, same with the overpressure relif valve, second, some pressure switches release the air in the line going into them as the turn off, this is to stop the compressor starting under load, not sure if it will make any difference though with the air con setup

[Wooders]

Things I see missing in the above are:
Regulator, ARB connection and oil return.....

Our setup is:

Air filter -> York -> oneway valve -> Oilfilter (with return to York) -> 6way Manifold ->
1. To Front Outlet
2. To Rear Outlet
3. Blowoff Valve Mounted on the manifold.
4. 130PSI Pressure Switch (which is wired to the compressor and to our ignition) also mounted on the manifold.
5. To the incab gauge.
6. To the 10L tank -> Regulator (set to 100PSI) -> AiRock controller system.

What we will be doing shortly is:
* Putting a second regulator set to about 80-85PSI for the rear outlet and for the ARB - because the full pressure we keep in the take is a bit much for some air tools and certainly not good for ARB seals.
* Then naturally we'll plumb the ARB into the OBA setup - instead of the ARB compressor.
* I was thinking of retaining the ARB compressor as a backup - but too be honest I don't think it has the balls to do what I need even as a backup - so I'm going to fit the ARB to the Wife's volvo and probably get a bit bigger 12V to run as a backup. This wouldn't normally be required - but without air I'm riding on my bumpstops.....
* also I am planning to run from the Lower regulator outles so I can pressurize the dizzy, blow cold air into the winch motor (to cool and pressurize it), also to pressurize the winch solenoid box.....etc....
* The Inlet will be plumbed to take air from the snorkel (which I haven't fitted yet).

Anyhow that's some of the ideas bounching about in my head - but I have a few other air ideas I want to utilise

[shorty_f0rty]

Guys, thanks for all your ideas... but a few questions.

... the pressure switch as close as possible to the pump, just in case you get a blocked line, same with the overpressure relif valve, second, some pressure switches release the air in the line going into them as the turn off, this is to stop the compressor starting under load,

Would the Pressure switch still be able to acturately determine the pressure if the tank intake is fitted with a one way valve? I'm assuming that as the air is being pushed into the tank, the pressure of the tank will be forced back to the switch?

Things I see missing in the above are:
Regulator, ARB connection and oil return.....

An oil return would require tapping back into the A/C comp would it not? This is not something I want to do. The lubricant on the intake and seperator on the output just requires more on-going maintenance does it not (empty/refill?).

I take it the regulator maintains the flow at a constant pressure on the output of the tank? Prefered for air tools, etc?

I also suppose it would be better safe than sorry if you had a blowoff valve on the comp output along with another check valve (is it really needed if there is one on the tank intake?)

I'm slowly gaining confidence with each reply to this post..

[hiluxv8]

setup looks ok.i have an oil/water separator on the firewall,so the outlet line from the compressor runs to that,then runs to the tanks through the check valve.i dont run an inline oiler before the compressor.i used to just top it up with oil evey now and then,but about 6 mnths ago i fitted a grease nipple to the filler plug on the compressor and just pump it full of grease.works well and doesnt leave the compressor as quickly as oil does.
i dont have a pressure switch either as i have a 800kpa blowoff valve on the tanks,so when i'm using the compressor it just keeps running till i switch it off.blows off at 800kpa,drops back to 700 kpa and keeps going.

[Wooders]

Guys, thanks for all your ideas... but a few questions.

Things I see missing in the above are:
Regulator, ARB connection and oil return.....

An oil return would require tapping back into the A/C comp would it not? This is not something I want to do. The lubricant on the intake and seperator on the output just requires more on-going maintenance does it not (empty/refill?).
.

shorty_f0rty,

Nah not quite what I had in mind - run the return back to the oiler which you have between the inlet & the pump.....

[shorty_f0rty]

Guys, thanks for all your ideas... but a few questions.

Things I see missing in the above are:
Regulator, ARB connection and oil return.....

An oil return would require tapping back into the A/C comp would it not? This is not something I want to do. The lubricant on the intake and seperator on the output just requires more on-going maintenance does it not (empty/refill?).
.

shorty_f0rty,

Nah not quite what I had in mind - run the return back to the oiler which you have between the inlet & the pump.....

AHUH! gotcha now.. that'll save havin to maintain the oiler and seperator i take it?

Also, is there any real need for an oiler on the output of the tank for airtools? I've talked to a few who have airtools and they dont have anything like that. Is it really necessary?

[ausyota]

Na you dont need to run an oiler for ocasional air tool use.
Just give the tools a squirt of oil into their air fitting once in a while and they will be fine.

[Bush65]

Guys, thanks for all your ideas... but a few questions.

... the pressure switch as close as possible to the pump, just in case you get a blocked line, same with the overpressure relif valve, second, some pressure switches release the air in the line going into them as the turn off, this is to stop the compressor starting under load,

Would the Pressure switch still be able to acturately determine the pressure if the tank intake is fitted with a one way valve? I'm assuming that as the air is being pushed into the tank, the pressure of the tank will be forced back to the switch? ...

The non-return valve should be just after the compressor, before the pressure switch or relief valve.

[Woop]

For your air set-up, use either braided hose or air-conditioner hose for the compressor discharge to cope with the high temperature of both discharging air and the engine bay temp. On the inlet to your air tank, use a T piece followed by a non return valve on the inlet to the tank. Connect the line from the compressor to the first port of the T Piece.

Next, thing to get is an adjustable type air pressure switch with inbuilt unloader valve. These can be found on most types of Tradesman type aircompressors. Connect the unloader Valve in the pressure switch to the 3rd port of the T Piece. Next connect the pressure measuring port of the pressure switch to a spare outlet of the tank. Install a Safety Valve somewhere on the tank. Run solid nylon hoses to Quick Connects on front and rear. Use an inline pressure regulator on a spare outlet feeding your airlocker--or set your pressure switch to 100psi instead.. Connect the 12V to the compressor clutch through the contact s on the pressure switch from a switch on the dash.

Using a pressure switch with an unloader means compressor starts under no-load and when tank is up to pressure, the unloader operates, venting the line between the non-return valve and compressor discharge, thus operating the no return valve preventing any leaks past the compressor rings.

Nick

[shorty_f0rty]

Hmm.. getting closer I reckon.. heres an updated setup.



using this setup means I'd only need a handful of bits and the bare minimum would be under the bonnet.

if i get time tomorrow i'll probably chase up the air comp place ive been chattin to and get some prices on the missing peices. thurs/fri i'll pay a visit to the A/C dude and see about discommissioing the A/C system.

is it just a matter of getting some pliers or whatever and cutting into the A/C line a fair distance from the compressor. this is all i really want the A/C dude to do.. id rather spend my own time removing all the other crap and hooking it all up.once the line is cut could you then install a barb/hoseclamp for the nylon hose to the other end or separators/oilers?.

if you dont mind i might put my shopping list here:
- inline oiler - air comp place
- oil/air seperator- supercheap/bunnings?
- intake filter - supercheap/bunnings/enzed??
- pressure switch with inbuilt unloader valve - air comp place
- T Peice - enzed/air comp place
- manifold - 4wd shop/air comp place?

i'm sure this will be of use to other people investigating the same thing..

[phippsy]

I've found Tony Powell Hose Supplies on Beaudesert rd pretty helpful, they have all the brass fittings, hose of different quality/price. Also IFS at Rocklea have a wide range of stuff, although it's not all on display like Tony Powell so you can't scratch around in boxes looking for what you want.

[bogged]

Woop is helping me do mine at moment, just shoppign for bits, and once done, will have a page up with info, parts, steps etc. Although at moment Im only using ARB Compressor. May go Bluetounge etc later.

Woopy runs 3 airtanks in his GQ, and quite a mega setup...



Question: Could you use more than 1 compressor?

[phippsy]

I don't see why you couldn't run more than 1 compressor, maybe current draw on the battery might be an issue? I guess so long as they were both connected via the pressure switch then they would only work for half as long to get a tank up to pressure. The size of the line to the tank may be an issue, so that it doesn't restrict flow.

[benjamin78au]

um why run 2 compressors , wouldn't 1 be plenty ? for redundency or are you thinking about electric ones. cause a mechanical one should pump out a sh*t load of air.

my 2 cents may not be right but

bj

[bogged]

um why run 2 compressors , wouldn't 1 be plenty ? for redundency or are you thinking about electric ones. cause a mechanical one should pump out a sh*t load of air.

Im running ARB now, but not sure how it will go with the air tank, so thinking of a Blue Tounge, Big Red, or similar and ARB as backup...

[Bush65]

shorty_f0rty,

That last pic - you still have the non-return valve on the wrong side of the pressure switch.

When pressure reaches the set point of pressure switch for rising pressure, the switch de-energises the compressor clutch and unloads pressure in line between compessor an non-return valve. When this happens, the pressure drops to the set point for falling pressure and energises the clutch on the compressor. So it will continually energise/de-energise the compressor clutch until it fails.

So put the pressure switch where it will see the pressure that is in the reservoir, not the pressure in the line between the compressor and the non-return valve.

[toughnut]

um why run 2 compressors , wouldn't 1 be plenty ? for redundency or are you thinking about electric ones. cause a mechanical one should pump out a sh*t load of air.

Im running ARB now, but not sure how it will go with the air tank, so thinking of a Blue Tounge, Big Red, or similar and ARB as backup...

Helped a friend set up an airtank on his work ute. (So I didn't stuff mine first). He used a 9kg fire bottle and it takes about 2min to fill from scratch. You get about 2 tyres pumped from 15psi to 37psi before the compressor kicks in. The best bit is how simple it is to rig up and it'll still give you some kick to pop a bead back on a rim if you need it. It's no good for sustained use though, such as air tools.

[shorty_f0rty]

shorty_f0rty,

That last pic - you still have the non-return valve on the wrong side of the pressure switch.

When pressure reaches the set point of pressure switch for rising pressure, the switch de-energises the compressor clutch and unloads pressure in line between compessor an non-return valve. When this happens, the pressure drops to the set point for falling pressure and energises the clutch on the compressor. So it will continually energise/de-energise the compressor clutch until it fails.

So put the pressure switch where it will see the pressure that is in the reservoir, not the pressure in the line between the compressor and the non-return valve.

hmm.. im still trying to interperate this..

the way im reading this makes me think you didnt notice the pressure measure line thats on the tank output. I haven't talked to the air compressor place yet but from what Woop said the pressure switch with inbuilt unloader valve ment it had a preasre measuring port on the tank output. Wouldn't this govern when the clutch is energised by the pressure in that line from the tank?

Next connect the pressure measuring port of the pressure switch to a spare outlet of the tank...

..Using a pressure switch with an unloader means compressor starts under no-load and when tank is up to pressure, the unloader operates, venting the line between the non-return valve and compressor discharge, thus operating the no return valve preventing any leaks past the compressor rings.

[Woop]

Industrial type pressure switches with an inbuilt UNLOADER VALVE have 2 ports. One port is for measuring the pressure required to activate/deactivate the switch mechanism. This port needs to be connected to your tank so its air pressure can activate the switch when the required pressure is reached--ie 120PSI. When the pressure drops, the switch will activate again.

The UNLOADER PORT is simply a small valve built in to the pressure switch assembly that operates in conjunction with the PRESSURE switch. When the pressure in the tank reaches the pre-set pressure, the pressure switch opens, turning off your compressor clutch, stopping pumping. At the same time, the UNLOADER valve operates, exhausting the air from the line between the compressor output and the non-return valve on the input to the tank. Air pressure in the tank forces the non-return valve to close.
When the tank pressure drops to cut-in levels,the pressure switch activates again, the UNLOADER VALVE closes, compressor starts, pressure builds up in the line to the tank forcing open the non-ruturn valve thus filling the tank..

Pressure switches can be adjusted for required cut-out pressure--normally the cut-in pressure is about 30PSI lower. Make sure you install a working Safety Valve in case of switch failure.

Nick

[dow50r]

Hi doods
The inline filter on the pressure side will catch the oil. This can be a water trap or a designated filter...if a water trap, the outlet can be auto drain back into the inlet oiler to make things go round..recycle etc...
Ive ran that particular compresser (Sandon 508) with no oil but a grease nipple as in Endless air setup...with no adverse effects. the water trap i have down stream collects grease for me and after that i have a check valve and safety valve (just to be sure to be sure) b4 going into a fire extinguisher.
Ive been told of an even better air receiver...an old out of date lpg bottle...complete with bleed valve or water drain :-)
It helps working in an industry that throws out alot of this stuff with upgrades...
Andrew

[Bush65]

shorty_f0rty,

That last pic - you still have the non-return valve on the wrong side of the pressure switch.

When pressure reaches the set point of pressure switch for rising pressure, the switch de-energises the compressor clutch and unloads pressure in line between compessor an non-return valve. When this happens, the pressure drops to the set point for falling pressure and energises the clutch on the compressor. So it will continually energise/de-energise the compressor clutch until it fails.

So put the pressure switch where it will see the pressure that is in the reservoir, not the pressure in the line between the compressor and the non-return valve.

hmm.. im still trying to interperate this..

the way im reading this makes me think you didnt notice the pressure measure line thats on the tank output. I haven't talked to the air compressor place yet but from what Woop said the pressure switch with inbuilt unloader valve ment it had a preasre measuring port on the tank output. Wouldn't this govern when the clutch is energised by the pressure in that line from the tank?

Next connect the pressure measuring port of the pressure switch to a spare outlet of the tank...

..Using a pressure switch with an unloader means compressor starts under no-load and when tank is up to pressure, the unloader operates, venting the line between the non-return valve and compressor discharge, thus operating the no return valve preventing any leaks past the compressor rings.

Sorry, my bad call. When I looked at the pic with the pressure switch against the tee in the line between the compressor and tank I jumped to that conclusion.

[Witchdoctor]

This all looks very time consuming & bulky. What is it going to cost to get it working (including labour). All this & still under 200PSi & slow

[bogged]

This all looks very time consuming & bulky. What is it going to cost to get it working (including labour). All this & still under 200PSi & slow

Under the price of a good air compressor on its own.. if using a sandan 508 $40 from pickapart....

Slow, what could you do that was faster to fill tires?

[dow50r]

Only thing ive seen thats faster is a co tank with regulator...or was that the nitrous
Andrew

[phippsy]

The only bulky thing I can see is the tank, which I thought would be under a tray or something anyway.

[MARKx4]

Is there anyway you can wire the the pressure switch into the compressor so it over rides the in cab on/off switch in the cab when it hits max pressyre and cuts back in once it hits a set minimum pressure like on a normal compressure.