peasea
Well-Known Member
Olives for compression fittings can be bought as copper or brass. Which applications are most suitable for the different metals?
Copper tube olives
- Thread starter peasea
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MoodySabre
Well-Known Member
The olive should be the same as the pipe.
I have always seen brass pipe for fuel or grease, copper for water or gas.
I have always seen brass pipe for fuel or grease, copper for water or gas.
VicS
Well-Known Member
Never seen any recommendations other than from Calor who say use the copper olives for gas (lpg).
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2Tizwoz
Well-Known Member
Wade fittings here advertised for compressed air supply a universal brass olive for use with copper and nylon tubes.
The olive fulfills the function of a packing, to prevent leakage from the fitting, and a mechanical fixing to prevent the pipe from leaving the fitting. A brass or copper olive will fulfill the clamping duty but a simple oval brass olive will require more pressure to cause it to deform. Calor no doubt advise the softer olive for gas as the pressures are low after the regulator and the tube and fittings need not be as highly stressed in order to deform the olive sufficiently to enable it to carry out its dual function. Gas fittings are not subject to water hammer and other forms of vibration usually so do not need to be resilient or capable of withstanding shock loads.
An olive also, as is clearer in the case of the asymetrical Wade design in brass,
forms its seal to the pipe at a narrow point at the tapered sharp end of the olive. If it is over tightened it can cut deeply into a soft pipe causing it to deform excessively.
Push in fittings separate the two functions using a resilient rubber ring and stainless steel mechanical fix.
The olive fulfills the function of a packing, to prevent leakage from the fitting, and a mechanical fixing to prevent the pipe from leaving the fitting. A brass or copper olive will fulfill the clamping duty but a simple oval brass olive will require more pressure to cause it to deform. Calor no doubt advise the softer olive for gas as the pressures are low after the regulator and the tube and fittings need not be as highly stressed in order to deform the olive sufficiently to enable it to carry out its dual function. Gas fittings are not subject to water hammer and other forms of vibration usually so do not need to be resilient or capable of withstanding shock loads.
An olive also, as is clearer in the case of the asymetrical Wade design in brass,
forms its seal to the pipe at a narrow point at the tapered sharp end of the olive. If it is over tightened it can cut deeply into a soft pipe causing it to deform excessively.
Push in fittings separate the two functions using a resilient rubber ring and stainless steel mechanical fix.
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pheran
Well-Known Member
Why? Most plumbing fittings are made of brass for use on copper pipe. In fact, such fittings are supplied with a brass olive!
daveyw
Well-Known Member
It's not just a calor recommendation to use copper olives on copper gas pipes, it's a CORGI requirement................and yes, before anyone says otherwise, CORGI does still exist!
Topcat47
Well-Known Member
This is true, but the fittings need to be relatively strong and besides the brass is cheaper than copper and more robust. The robustness of the olive, however, is a problem, not an advantage, as the pipe material will defore before the olive. I always replace these brass olives with copper for this reason. I do this for water as well as gas pipes.
The reason gas fittings require copper olives is that gas finds its way past smaller imperfections than liquids and it is very difficult to ensure a gas tight fit with brass olives on copper pipe. Amateur plumbers will find it hard enough to get a water tight fit with a brass olive.
The reason gas fittings require copper olives is that gas finds its way past smaller imperfections than liquids and it is very difficult to ensure a gas tight fit with brass olives on copper pipe. Amateur plumbers will find it hard enough to get a water tight fit with a brass olive.
VicS
Well-Known Member
The pipe cannot deform before the olive , it is only the olive being (over)tightened onto the pipe that deforms it.
Brass olives require more effort to compress them onto the pipe but copper olives, requiring much less effort, are more likely to be overtightened resulting in deformation of the pipe.
2Tizwoz
Well-Known Member
Brass olives are better when a harder pipe material such as stainless steel or chromed brass or copper is being used.
rascacio
Well-Known Member
I agree with you, brass is better for harder materials,but any olive will work on just about any material including plastic if you don't overtighten it.Overtightening is the number 1 reason for failure,end of story !! When tightening up a good rule of thumb is to just hand tighten and then add a 1/2 to 3/4 turn with a spanner. If there is a problem you can add a bit more of a turn whereas if its overtight to start with and leaks its knackered !! (Bodgeing required or cut pipe and start again)
This is just a rough guide for those not familiar with the process. Once you get the feel for it it's a piece of cake.
One more thing I'd like to add is if you are working on water systems I would recommend plastic (barrier) pipe and demountable push fit fittings for all concealed pipe work hot or cold securely mounted of course. In my experience (27 years as a plumber) I've never had a problem with any plastic pipe systems from any of the major manufactures.
This is just a rough guide for those not familiar with the process. Once you get the feel for it it's a piece of cake.
One more thing I'd like to add is if you are working on water systems I would recommend plastic (barrier) pipe and demountable push fit fittings for all concealed pipe work hot or cold securely mounted of course. In my experience (27 years as a plumber) I've never had a problem with any plastic pipe systems from any of the major manufactures.
