Ingersol rand type a general questions.

[roblane65]

Last week I picked up an old ( 71 ) ingersol rand compressor and not having a great deal knowledge
on them I've some general questions . And please correct me if I'm wrong anywhere.
briefly it starts and runs up to 150psi (in about 3 1/2 minutes )and stops, open the drain and it cuts back in about 90 psi with no nasty noises or vibration. The mounting plate for the motor and comp are covered in oil crud so I suspect there's an oil leek on the compressor .but a local shop tells me they can get the gasket sets for a type A. So I'm hoping its worth spending a bit of time and money on it cost me £55 and a half hour drive.

My questions are are on the side of the comp theres a a large bolt and a grub screw underneath
is this the oil fill and drain

so I've been told its SAE 30 mineral oil does it just fill to the bottom of of the plug as its no where near at present.
what should I use to make an air filter element at present its a bit of foam.

the questions are still coming !
On the receiver outlet theres a 3/8 tee with a valve I'm presuming its the blowoff / safety valve .
has this got to be mounted vertically as I'd like to pipe the new regulator with a take before it and one after if that makes sense

and should I fit a new valve for safety sake ?
and finally I think Ive gone ott with the new regulator/water trap !

And lastly off the outlet of the compressor theres a tee back to the presure switch with a valve type thingy which is wired to the motor is this the unloader valve ? purely guessed by its position

anyone with first hand knowledge appreciated

 

[Seadog]

I don't have the exact model, mines a Type B, but it's similar enough. The large angled bolt is the filler, I fill to the bottom with SAE30 (ISO100) compressor oil (no detergents or other additives). The original filter element was horse hair. The valve is the safety valve, if you want to replace then do. The receiver will have the rated pressure, working pressure, and test pressure stamped into it. Get a valve near the rated pressure, or slightly above. The line back to the Danfoss pressure switch is the unloader.

 

[roblane65]

Thanks seadog does the SV have to be mounted vertical ? I'll check the tank and plate for presures, I'm struggling to keep the plumbing tightish to receiver with out coming out miles and is there any real benefit in having one unregulated outlet , i was thinking I could use that for the plasma cutter as it has a built reg and the it would get better air flow hence trying to keep all the plumbing above 1/4 Bsp.
yours will be the twin P two stage then theres one ebay now wanting over £600 !

 

[Seadog]

I don't think it has to be. In fact one of my other compressors has it mounted horizontally. The standard outlet size is probably 3/8" BSP.
Mine has yet to be plumbed in but, depending on the run and what you intend running from it, it may be better to have a large bore to your work area and then to regulate from there. Make sure that the pressure doesn't exceed the maximum that the equipment will withstand, so you may need a separate regulator adjacent to your plasma.

 

[roblane65]

It certainly is 3/8's . Its just for the garage/ workshop now so no long runs of pipe work just a bit plumbing straight of the receiver for now , although the reg, I got can be wall mounted if needed. the plasma ( hypertherm) has got its own builtin regulator so should be good there Just need a pile of BSP fittings ! does it matter if you mix the materials of the fittings i.e S/S mallebal steel / brass.
thanks seadog.

 

[Seadog]

I wouldn't worry about mixing fittings. The compressor uses malleable iron and brass anyway. The addition of a few stainless bits won't be detrimental.

 

[roblane65]

Update. new plumbing nearly done one regulated and one not . I had to use a union as couldn't get the
reg where I wanted it , its all 3/8 mallebal . And i'll get some new XF / euro fittings to replace the old bayonet ones.

I've replaced the .75 flex supply with some 2.5 H/D rubber flex and i'll also do the pressure switch to motor as well
also the unloader need rewiring and I'm missing an earth !


I'll update when I get a bit more done.

 

[Seadog]

also the unloader need rewiring

It's mechanical.

 

[cheb]

It might not be an oil leak, it might been overfilled and sprayed oil all over from the breather. I've got one very cheap for this reason many years ago, the mechanics poured in oil until the sight gauge was covered. When it had blown enough out to see a level they refilled it. Stopped it rusting though.

 

[roblane65]

It's mechanical.

Give us a clue why it's wired to the control box on top of the motor ? I just presumed it was just a solenoid
powered when the motor started then overidden by pressure. I'll get some better pictures up.

 

[brightspark]

the pressure switch is just a make and break contactor operated by air pressure

 

[Seadog]

The unit is a pressure switch. It connects or disconnects power to the motor by virtue of pressure acting on a diaphragm which bears against a spring. When it's up to pressure the mechanism trips and switches off the motor. The action of the switch activates a needle valve, which is the unloader valve. The unloader is purely mechanical.

https://www.mig-welding.co.uk/forum/threads/ingersoll-rand-compressor-resurrection.99662/page-5

 

[roblane65]

checked the link ,tidy job seadog my pressure switch is different to yours maybe later model.
I will do some more pictures though. so whats the offending blue item thats wired and tee'd of the outlet pipe of the compressor ? I'd presumed this was the unloader valve ?

 

[Seadog]

Thanks. Well, I'd have to say that it looks the same from what I can see of it. And considering there is only two years between yours and mine, and that they're the same family, I'd be surprised.

I wait with interest.

 

[roblane65]

Yea but whats the blue thingy ?
mine hasn't got the 180 degree on/off switch on the end of the pressure switch it's
just a small toggle switch on the side .

 

[brightspark]

Yea but whats the blue thingy ?
mine hasn't got the 180 degree on/off switch on the end of the pressure switch it's
just a small toggle switch on the side .

its a solenoid valve and wired in to the motor so must only operate when the motors running

 

[roblane65]

OK i'm gonna sit and think about this a bit . Well my solenoid valve needs rewiring then

 

[Seadog]

I see what you're saying. It's not clear how that valve, which as you rightly said could be the unloader, is coupled to the power switch and the motor. There only appear to be two working sets of contact on the switch block.

Ah, the valve is paralleled with the motor and is normally open. When the motor switches off the valve loses power and opens the unloader port.

 

[roblane65]

Your far more articulate Than I Mr Seadog . I was struggling to get my head around how the system worked.
when you did your rebuild were the pulleys fairly easy to remove as I'm going to have remove mine as the cage needs rebuiding it's in a poor state . youv'e done a really nice job on yours .

 

[Seadog]

I try Rob, I try

The cage on mine was slightly out of shape with a couple of broken wires. I silver soldered those back together and bashed it around until more or less true. You'll be lucky to get it perfect, it never was from the factory. Both of the pulleys were buggers to remove. I had to resort to large 3-legged pullers, heat, and shock tactics. Having said that, the pump was the worst. I ran a reamer through and found that the bore was distorted.
What it the model number of your pump. There's not enough of the label in view to make it out. It certainly seems to be rare since I've failed to find another image of a single stage IR from that period.

You should be able to hear or feel the solenoid valve operating. I would have thought it unusual to seized in the closed, i.e. powered, position although anything is possible.