Brass Isolation valve to plastic pipe

[Mattatooi]

Can you use the brass olive on plastic pipe or do you need to get something different? Its cold water supply for a washing machine.

 

[Belboz]

AFAIK you can use plastic pipe into compression fitting but require a pipe insert and a copper olive (not brass)

Could be wrong though so best to await one of the experts on here.

 

[SandyLyon]

AFAIK you can use plastic pipe into compression fitting but require a pipe insert and a copper olive (not brass)

Could be wrong though so best to await one of the experts on here.

Yes, use pipe insert, copper olive no jointing paste, can use PTFE tape if needed.

Also if you are using Speedfit be careful which of their inserts you use, there is a thread on this forum about Speedfit inserts.

 

[oldbuffer]

On the plastic pipe end of the compression fitting use a copper olive, not brass, and don't forget to put an insert into the plastic pipe. If using John Guest Speedfit pipe and fittings, the insert should be one of those WITHOUT extra O rings (TSM standard inserts). If using Hep2O all the inserts are the same. If using any other make, check with the manufacturer.

On the copper pipe end it doesn't matter whether you use brass or copper. If you are going to re-use the existing olive, make sure its clean and burr free. Then I'd put two or three wraps of PTFE tape around the olive (wound on so that the nut doesn't unwind it) or, in my view better, a little jointing paste, preferably Jet Lube V2.

 

[Mattatooi]

Sorry for confusion, its a brass valve, but the olive bit is copper. Just wasnt sure if you could use that on a plastic pipe. I have the inserts for the pipe and all. So should be all ok then. Thanks

 

[Madrab]

I have to be honest in saying that IMO it doesn't matter whether you use brass or copper olives as the olive seals against the fitting/nut and not the pipe. Actually, copper olives are softer and are are easier to overtighten and can actually deform the plastic and snap the insert if overdone.

If it's a new coupling, no PTFE should be needed but I find that's down to the individual.

 

[denso13]

So should be all ok then

Yes, go for it.

 

[SandyLyon]

I have to be honest in saying that IMO it doesn't matter whether you use brass or copper olives as the olive seals against the fitting/nut and not the pipe. Actually, copper olives are softer and are are easier to overtighten and can actually deform the plastic and snap the insert if overdone.

If it's a new coupling, no PTFE should be needed but I find that's down to the individual.

So all the plastic fitting manufacturers are wrong then regarding copper olives.

And if the olive doesn't seal on the pipe what stops the water creeping between the pipe and olive ?

 

[Madrab]

They used to quote that copper olives are recommended to brass as copper is softer they didn't specify that brass couldn't be used. Used brass countless times without issue.

If you've ever been to a diy job where a copper olive was used though and been over compressed, that has then subsequently bitten into the pipe, caused a side loading weak spot on the insert which then then snapped and a flood has ensued...

 

[St0rmer66]

I've used brass olives too with no problems. Not all brass is the same though. The stuff they use for olives is usually fairly soft but I remember not so long back Worcester had to change the brass they were using on the gas connection to their new boilers. You could tighten it up as tight as you can and still pull the gas pipe right out of the fitting! They never officially admitted fault (no recall etc) but changed the brass anyway...