Atlas Copco Compressor problem – please help guys

[Manchecd]

Yes, I think the lip is deliberate. I do not get the impression that there is any compression involved with the olive when the nut is tightened.

Maybe an olive is not the best way to describe it - perhaps it would be better to say that it is a tapered press fit connector.

The internal diameter is wider at end where you slide it over the pipe. It is five-eights of an inch and it tapers down to about a bit more than nine-sixteenths of an inch. I cannot be too accurate as I do not have an internal micrometer and have been relying on a vernier gauge to do the measurements.

Colin

 

[tigler]

It does compress, against the internal taper of the female part it connects to.
It's an automotive tube fitting system used widely in Europe.

 

[Manchecd]

Hi guys

Thanks for later comments.

As you will have seen from my last post, it is 5/8" not 3/4".

I think it will seal OK if I can get it back on the pipe without damaging it.

I am inclined to think that it is the internal lip that will keep it on the pipe. I am doubtful if it will compress sufficiently if I do not get the internal lip over the pipe. When you slide it on the pipe, before you reach the lip, there is some sideways movement i.e. you can rock it a little bit from side to side. It is a bit more than a sliding fit at this point.

Is it possible that there might have been a special tool to get these fitted in the first place?

Colin

 

[Manchecd]

Hi Tigler

I had not read your reply when I posted the previous message and obviously I'll defer to your much better knowledge on this.

Is it worth trying to put it on with it slid up as far as the internal lip and then tightening it?

My only worry is whether this will damage the part.

Thanks.

Colin

 

[tigler]

No tools are used to assemble this system, the olive or ring seal, as it's known, is just placed on the nipple or standpipe and the nut tightened up.
My advice would be to put the ring seal back on, push it on as far as possible by pushing the assembly hard against a flat surface, then thighten the nut. If it works it works, if not it will just need a new end on the hose or a new hose as I mentioned previously.
There is no other possibilty, the parts are not intended for frequent re-use, if you get away with it then fine but there is no certainty.

 

[Fintray]

Manchecd

That fitting looks as though it is one piece of brass rather than an olive over a length of pipe. Have a very close look and see if it has fractured rather than came off. If so probably easier to take the pipe to somewhere like Pirtek to get them to make a replacement.

 

[tigler]

That is possible as the photos are slightly out of focus so difficult to see clearly. If that were the case then it will be a cone seat male hose nipple and nut. Not repairable would need a new fitting crimping in. Or, the old one could be removed by cutting through the ferrule and the new held in with a hose clip.

 

[Manchecd]

Hi guys

Thanks for your suggestions.

It looks as though it is one piece of brass, Fintray, but I have looked very carefully at it and cannot see any signs of a fracture.

I will have a go at fitting it tomorrow by pushing it on as far as I can and then tightening the nut.

Any thoughts on whether it is worth applying a bit of heat to the brass ring seal before pushing it over the pipe to see whether that expands the metal enough to get the end of the pipe over the internal lip?

Can I also ask, if I do need to remove the pipe, is it simply a case of undoing the single nut at the other end (best seen in the first picture on p 2 of the thread). I say "simply" because I have put a socket over the nut and tried to move it with a long bar over the ratchet to get extra leverage and it seems reluctant to move.

Then again, I suspect it may not have moved since it was put on when new!!

Thanks a lot.

Colin

 

[rtbcomp]

If a union won't budge it may have been assembled with some sealing compound, getting it hot should release it.

 

[tigler]

Try tightening slightly before trying to loosen. If it's still tight, make sure you use a 6 point socket and shock it loose rather than apply progressive force, better still use an impact gun.

 

[Mick - Ford Focus]

Manchecd

The Ring Seal Olive Thing With The Lip Is Intended To Be Just Slipped On And The Nut Fastened Down - It Is The Seal - No Heat Required.

Don't Remember Where I've Seen Them But That's All I Required To Get A Seal - On Something, Years Ago, In The Dim And Distant Past.

Mick

 

[Manchecd]

OK, guys, thanks for this good advice and I will have a go at making further progress (hopefully ...) tomorrow.

Cheers,

Colin

 

[Manchecd]

Hi guys

I have made some progress to today but still some way to go.

Tightening up the nut with the ring seal pushed on the pipe as far as it would go still meant that the pipe was loose and would not hold, so I decided to it was best to see whether I could get a new ring seal.

I managed to remove the outlet pipe at the tank end (nut very tight but eventually moved) and took the outlet pipe, ring seal, NRV valve and inlet pipe to Compressed Air Services in Birmingham, who were very helpful.

They had a good look at the NRV valve and noticed a nick on the sealing surface which I had not spotted (I will be making an appointment at the opticians soon ...). They thought it would not seal and the NRV needed replacing.

This is not straightforward because the thread on the pipes to the NRV valve are not the same as ones used now, so to cut a long story short I am waiting for a converter, with one side the same as the existing threads and the other BSP to enable a modern NRV to be used.

I am hoping the converter will be coming in tomorrow and things can progress from there. With luck a new NRV valve will solve the problem, but if it does not at least I will know that there are no problems with the NRV and can then look again at the pressure switch/unloader valve side.

Many thanks for all you help so far and I hope to be able to report good progress tomorrow.

Colin

 

[tigler]

Will be interested to see the new arrangement.

 

[Manchecd]

Hi guys

Generally good progress today.

I am keeping the old NRV without the internals as this bolts in place on the compressor and holds the input pipe firmly in place and I should be able to use the pipe from it to the unloader valve.

I have a new NRV attached into the outlet of the old NRV casing which should prevent air leaking back from the tank. I say "should" because I Have not had a chance to test it properly yet.

The reason is that there is a bad leak on the end of the outlet pipe where it is screwed into the tank. This was down to me.

The big nut and tube that goes through the round metal piece at the end of the pipe and then screws into the tank (sorry, I do not know the technical term for this connection) was extremely tight and it looked as though the end of the hose could be unscrewed where it connects into the round metal piece at right angles. There was a nut type end which turned when I put a spanner on it and the thinking was that I could undo the pipe connection here rather than having to release the bit tight nut.

Big mistake!! The "nut" kept turning round but it soon became apparent that it was not threaded and would not undo. So I stopped turning it and eventually managed to undo the big tight nut to release the pipe. However, the effect of disturbing this "nut" is that the pipe now leaks at approximately the same rate as the pump is trying to pump into the tank!!

So, I will have to get a new fitting on the end of this pipe. I am not going to be able to do his till after Easter as we are away from tomorrow until Wednesday.

Once I have done this and managed to get some air into the tank, hopefully everything will then work OK. I will post up a photo on the new arrangement next week when I have been able to get back to it.

Cheers and have a good Easter.

Colin

 

[tigler]

That looks like a banjo connection, so would replacing the copper sealing washers stop it leaking ?

 

[Manchecd]

I think it is a banjo connection, Tigler, but the leak is not from where the sealing washers are (there is one on top of the tank and another underneath the nut, with the circular metal "hoop" piece attached to the pipe "sandwiched" in between).

The leak is where the end the pipe goes in at right angles into the circular metal "hoop" piece.

Hope this is intelligible and makes sense!! I know what I mean but it is not easy to describe when you do not have the technical terminology!!

Colin

 

[tigler]

You mean where the hose is crimped to the banjo (hoop) fitting ?

 

[Manchecd]

Yes, that's it!!

More to follow after Easter ...

 

[tigler]

If it's leaking there the only solution is to re-crimp the hose but that needs the end of the hose to be cut off, making it shorter, possibly too short to re-use. I have the bits to make a new hose but it wouldn't be viable when taking postage into account, compared to doing it locally. Or, you could cut off the ferrule to release the hose from the banjo, cut off the used bit of hose, then use a hose clip to re-attach, doesn't look as neat but hey !