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Why are my copper LPG olives so hard to tighten? Am I just getting weak?


starman

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I can’t recall having problems in the past but I’m having the devil of a job getting copper olives to ‘bite’ on my 3/8 soft copper lpg pipe and fittings. I’ve always been conscious not to over-tighten compression fittings but it’s taking quite a lot of spanner action to stop fittings simply dropping off. And even when they’re on they still can be moved which doesn’t seem right . I’m using no tape or ‘goo’ btw.


 

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Do the compression nuts spin onto the fittings easily with the olives removed from the fittings?

If not the fitting or nut threads are malformed.

If they do the olives have probably not bee properly annealed.  Heat ' em to just red hot and allow to cool.  You can do a few at a time on a gas ring  if you have no blowlamp handy.

 

N

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2 minutes ago, BEngo said:

Do the compression nuts spin onto the fittings easily with the olives removed from the fittings?

If not the fitting or nut threads are malformed.

If they do the olives have probably not bee properly annealed.  Heat ' em to just red hot and allow to cool.  You can do a few at a time on a gas ring  if you have no blowlamp handy.

 

N

No problems like that - new fittings, new pipe (and even new cutter!)

they are flat olives not shouldered in

any way like brass ones. I’m just wondering if that’s making it harder or maybe the cold weather has hardened everything up a bit. 

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Correct pipe Tony and these are the olives:

https://www.bes.co.uk/wade-parallel-soft-copper-olive-imperial-3-8-9542/
 

29 minutes ago, Tony Brooks said:

Not metric fitting with imperial nuts by any chance?

 

Are you sure it really is 3/8 pipe? If its 10mm I understand it has a thinner wall so tends to crush under the the olive.

 

13 minutes ago, TheBiscuits said:

 

You're not trying to use tube trimmings as olives by mistake are you?  I think you need the chamfer to allow the fitting to compress the olive.

 

(Don't ask me how I thought of this possibility!)

 

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50 minutes ago, starman said:

I can’t recall having problems in the past but I’m having the devil of a job getting copper olives to ‘bite’ on my 3/8 soft copper lpg pipe and fittings. I’ve always been conscious not to over-tighten compression fittings but it’s taking quite a lot of spanner action to stop fittings simply dropping off. And even when they’re on they still can be moved which doesn’t seem right . I’m using no tape or ‘goo’ btw.


 

Did you anneal them? I think that many of these olives that are imported will not have been annealed - it saves money . . .

If using brass olives (not recommended) then the copper pipe can be annealed . . .

Edited by NB Alnwick
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Another thought - I recently bought some 22mm stop ends and found that the internal thread was tapered and tightened long before it reached the point at which it would make an effective seal. The solution was to tap them out with a proper plug tap.

 

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1 hour ago, NB Alnwick said:

Did you anneal them? I think that many of these olives that are imported will not have been annealed - it saves money . . .

If using brass olives (not recommended) then the copper pipe can be annealed . . .

No I haven’t annealed them. Never thought about it - I’ll give it a try.

 

And, yes, they are Wade fittings and I’m pretty sure all the stuff is correctly sized.  

Edited by starman
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26 minutes ago, BEngo said:

I suggested annealing at post 2!

 

N


You did indeed - apologies! But I just checked the specs with Wade and they are in fact annealed. 
The factory specs also say that for this size (3/8) they should be done up hand tight then spanner tightened a further 11/4 to 11/2 turns. 

I’ll do a test piece like this and see where we go. 
My concern is that even when the olive appears to be nipped up the fitting can still be turned on the pipe. That surely can’t be gas tight?

Edited by starman
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All the stuff is the right size - it’s straight from BES & Wade and I’ve re-measured too. 
 

What I have also done is experiment with the doing up  11/4 turns from finger tight as recommended by Wade - and that is ferociously tight on the 3/8 stuff. It certainly locks everything up but needed a couple of hefty spanners to achieve. Tighter than I would have gone normally. 
 

Sounds daft but maybe the cold weather has hardened stuff up...

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1 minute ago, starman said:

All the stuff is the right size - it’s straight from BES & Wade and I’ve re-measured too. 
 

What I have also done is experiment with the doing up  11/4 turns from finger tight as recommended by Wade - and that is ferociously tight on the 3/8 stuff. It certainly locks everything up but needed a couple of hefty spanners to achieve. Tighter than I would have gone normally. 
 

Sounds daft but maybe the cold weather has hardened stuff up...

On plumbing size compression fittings from say Peglers or Yorkshire Metals  in 15mm and upwards to 28mm sizes they used to recommend finger tight and half to threequarters a turn with a spanner but this is on half hard copper pipe and you are on soft copper pipe, makes a big difference.

If you lubricate the thread you will find a difference.

I would think that the olives are not annealed after forming from fully annealed copper and therefore will have some hardness as copper quickly work hardens.

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14 minutes ago, Tracy D'arth said:

On plumbing size compression fittings from say Peglers or Yorkshire Metals  in 15mm and upwards to 28mm sizes they used to recommend finger tight and half to threequarters a turn with a spanner but this is on half hard copper pipe and you are on soft copper pipe, makes a big difference.

If you lubricate the thread you will find a difference.

I would think that the olives are not annealed after forming from fully annealed copper and therefore will have some hardness as copper quickly work hardens.

I’ll certainly try that. Perhaps I have also been making the job harder for myself by not using any sort of pipe sealant or Ptfe tape (because it’s frowned upon) which would have lubricated the doing up. 

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4 minutes ago, starman said:

I’ll certainly try that. Perhaps I have also been making the job harder for myself by not using any sort of pipe sealant or Ptfe tape (because it’s frowned upon) which would have lubricated the doing up. 

If you use sealant, non setting plastic is the stuff.  Never PTFE on anything under 1/2" BSP threads, not on olives either.

 

 

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It is worth noting that copper does harden slowly over time, maybe you got some olives that were old stock.

 

On annealing, here  it is more important to preserve the metal than to gain maximum softening. To that end only take the olives up to a dull read heat, a bright cherry red is not needed and will increase oxidisation. The olives may be quenched if desired and this will tend to shed oxide.   If it is desired to get the component very clean then dunking in vinigar for a short time will usually do the trick but don't put it on 'yer chips afterwards.

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13 minutes ago, Man 'o Kent said:

It is worth noting that copper does harden slowly over time, maybe you got some olives that were old stock.

 

On annealing, here  it is more important to preserve the metal than to gain maximum softening. To that end only take the olives up to a dull read heat, a bright cherry red is not needed and will increase oxidisation. The olives may be quenched if desired and this will tend to shed oxide.   If it is desired to get the component very clean then dunking in vinigar for a short time will usually do the trick but don't put it on 'yer chips afterwards.

Drop the olive in your Coke and swirl the glass as you drink!

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54 minutes ago, Tracy D'arth said:

Drop the olive in your Coke and swirl the glass as you drink!

Like cleaning old pennies!

BTW the spot of oil tip was a good one - still needed some spanner work but much easier. Thanks. 

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1 hour ago, Tracy D'arth said:

  Never PTFE on anything under 1/2" BSP threads, not on olives either.

 

 

Why?

After a lifetime working with oil heating and cooking where much pipework is as little as 1/8" BSP on Agas, but rarely above 3/8" BSP on boilers, PTFE is favourite, sometimes with a sealer also, preferably Heldite. Remaking 6mm compression oil feed pipes into Aga burners , a turn or two of PTFE around the olive is recommended practice.

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13 minutes ago, Ex Brummie said:

Why?

After a lifetime working with oil heating and cooking where much pipework is as little as 1/8" BSP on Agas, but rarely above 3/8" BSP on boilers, PTFE is favourite, sometimes with a sealer also, preferably Heldite. Remaking 6mm compression oil feed pipes into Aga burners , a turn or two of PTFE around the olive is recommended practice.

Gas regulations approve plastic non setting compound and heavy gauge PTFE as sealing materials but the use of PTFE on fittings smaller than 1/2" bsp is frowned upon.

 

I don't know why either.  Unless its the risk of getting it inside the fittings and pipe.

 

I have never found PTFE to be brilliant with diesel fuel, it always seems to go brown and weep.

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