anyone understand olives?

O

oldvarnish

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They seem to come in two types.

There's one kind which are simply rings, and there's another type which has a bevelled edge.

What's the difference, and which do you use for which application?

Do you use different fittings with different rings, and how do you correctly describe and match them?
 
whenever I've taken a 'rounded' olive out of a compression joint, it has usually deformed a bit to an assymetrical cross-section, close to a bevel. Perhaps bevels are a method of reducing the pressure required to make a good fit.


I am not aware of fittings needing one or other of the two types. Giblets will know.
 
My guess is that the beveled olives are brass type material and the round one's that look like a very small piece of copper pipe are actually soft copper and that is what you require if using on a gas joint on a boat.
The soft copper does not need to be beveled like the brass olive, as being soft it self shapes to make the gas tight connection in the beveled female fitting.
 
Paul, you can get both beveled and plain brass and copper olives which should both be fine with most compression joints. You may find that the plain brass ones "squeal" when you are tightening the nut but a spot of light oil will help (not on oxygen lines though!:eek:). There are some brass ones that are VERY hard (Honeywell controls springs to mind) and I usually chuck them out and use either standard brass or copper ones. FWIW I use the copper ones where the fitting may be a bit tricky to get to so prohibiting the usual "force" ;)

The ones you have to be wary of are the tapered ones as these are normally meant for one specific type of fitting (Wade?). Do not try and use these in a standard compression fitting.

Hope this helps.

Pete

BTW I can tell you are a true chentleman as most folk do not know that the compression rings are also called olives.:)
 
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oldvarnish said:
They seem to come in two types.

There's one kind which are simply rings, and there's another type which has a bevelled edge.

What's the difference, and which do you use for which application?

Do you use different fittings with different rings, and how do you correctly describe and match them?
Click to expand...

The bevelled ones are usually brass.

The plain "rings" are usually copper.

For most purposes you can use either BUT the copper ones are recommended for use on gas systems

BTW you may be interested in http://www.thomson-caravans.co.uk/advice/diyprojects/gascompressionfitting.htm
 
I had trouble with olives recently too.
Changing the short copper pipe (with branches, -about 32mm dia main pipe) that connects to a ballvalve skin fitting and which brings three drain hoses into this valve I decided to change the olive.
The one coming out the ones I bought (got two just in case!) were different.
Original was bevelled, but dissimilar bevels. A short high angle bevel one side, and a longer more tapered bevel other side. Total width of olive was 12mm.
New ones were symmetrical, and only 8mm.
When tightening the nut, which should compress the olive onto the tubing, I found the nut had travelled all the distance up the thread and still not compressed. It leaked on re-launching the boat last week.
So I added the second olive, covered the lot with PTFE tape and tightened it up. Good job, no leaks and hope it lasts a long time.

The leak was about 1 drip per second. I figured that would be a lot in a boat for several weeks unattended!

So not all olives are equal !
 
Giblets said:
BTW I can tell you are a true chentleman as most folk do not know that the compression rings are also called olives.:)
Click to expand...

I was once in a remote part of Norway with a fractured fuel pipe and no olives to make a repair. I found a plumbers merchant, but how to explain what I needed with not a word of Norwegian? So I acted it out with my hands, drew a picture...this went on for some time. The man behind the counter turned to me and said, in perfect English, 'what you need is an olive!'
 
VicS said:
Reasons given in the link I posted earlier! Post #5
Click to expand...

Yes, I've seen that statement by Calor before:

Calor recommends the use of soft copper olives . These olives are easier to compress and therefore easier to produce a good seal. Brass olives, which are harder, become brittle in use and the joint can leak or fail at the point where the brass olive engages the coupling body.

It doesn't in any way explain why olives for use with gas should be any different from olives used in any other application.
 
From my apprenticeship days many years ago, a tradesmam thought that the two outer edges work hardened first followed by the center section that then formed the seal. I don`t know if he was correct or pulling my leg. :confused:
 
VicMallows said:
Yes, I've seen that statement by Calor before:

Calor recommends the use of soft copper olives . These olives are easier to compress and therefore easier to produce a good seal. Brass olives, which are harder, become brittle in use and the joint can leak or fail at the point where the brass olive engages the coupling body.

It doesn't in any way explain why olives for use with gas should be any different from olives used in any other application.
Click to expand...

I don't think the olives used with gas are "different" ... nobody AFAIK offers special olives for use with gas.

Its just recommended, for the reasons given by Calor, that copper olives are used rather than brass ones.
 
VicS said:
Its just recommended, for the reasons given by Calor, that copper olives are used rather than brass ones.
Click to expand...

Becoming circular. OK, Calor have an OPINION which appears to be unrelated to the gas/fluid the pipe caries. Maybe they would choose to use copper olives whatever the application or the size of tube. Fine.

Presumably others have a different opinion since brass olives are normal with all sizes of tube.

A rest my quest for the reason.
 
A tiny leak with another fluid, like air, water or oil, would be little more than a nuisance and would sometimes even 'heal itself'. A similar leak when the fluid is gas could prove lethal. Since it is easier to get a good and tight joint using plain soft-copper olives it makes sense - to me, at least - to advise in favour of these over the other brass types.
 
oldvarnish said:
They seem to come in two types.

There's one kind which are simply rings, and there's another type which has a bevelled edge.

What's the difference, and which do you use for which application?

Do you use different fittings with different rings, and how do you correctly describe and match them?
Click to expand...

The bevelled edge ones usually have had the stone removed by hand, whereas the straight-edged ones are machine stoned. The amount of vinegar in the pickle usually determines the degree of brittleness...

Sorry - someone had to. :D
 
I've never understood brass olives on copper pipe, but then I'm an Electronices Engineer....

Seems to me that the seal material should be softer than the materials being sealed, or at least not harder.

I always replace any brass olives supplied with a fitting from my bundle of copper ones bought in bulk a while ago - before the price of copper went through the roof.

Anyone when brass olives are the preferred type?
 
Chalker said:
I've never understood brass olives on copper pipe, but then I'm an Electronices Engineer....
Click to expand...
Where I worked for a a couple of years cleaning and maintaining accommodation the "volunteer" helpers over the years had used whatever came to hand to work on central heating. Many 10mm copper pipes were rendered useless by brass olives cutting into them. A bit of vibration or a blow and they started leaking. You took the radiator off and the pipe came with it.
 
I bought an Alde 'marine' gas bubble tester recently, a long established and reputable maker. The compression fitting olives (like everything else) are brass. They are unidirectional with a stepped profile and seem carefully engineered (turned?) compared to plain 8mm. olives, so I think I will risk using them. My reasoning is that if the Alde olives were inferior to the plain copper ones which would be much cheaper to make, they would surely have found out about it long before now and changed to the cheaper ones.
 
Quandary said:
I bought an Alde 'marine' gas bubble tester recently, a long established and reputable maker. The compression fitting olives (like everything else) are brass. They are unidirectional with a stepped profile and seem carefully engineered (turned?) compared to plain 8mm. olives, so I think I will risk using them. My reasoning is that if the Alde olives were inferior to the plain copper ones which would be much cheaper to make, they would surely have found out about it long before now and changed to the cheaper ones.
Click to expand...

I would also stick with the olives supplied. I imagine the fittings will be engineered to suit the design of the olives supplied.
 
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