Compression fitting tightness on plastic pipe?

MJN · 15 Apr 2019

When using compression fittings on copper pipe I've always hand-tightened plus half a turn. I think it was just a rule of thumb taught to me by my Dad. I was wondering, however, how tight I should make a compression fitting to plastic pipe - more/less/same? My intuition is saying it should be the same.

If it makes any difference the pipe in question is 15mm Hep2O barrier pipe and I am connecting to a TRV. Incidentally, I am aware of the importance of using an insert.

undertrained · 15 Apr 2019

I think it’s the same, if it starts to weep then nip up.

dilalio · 16 Apr 2019

Copper or brass olive? Makes a difference

Just tight enough not to leak

Gasguru · 16 Apr 2019

I hate plastic and I've seen too many major floods to know how risky it is but if I'm forced to use it then copper olives and a smear of paste on the threads (to reduce friction) is the way to go.

One house I went to had a joint fail in the kitchen..it was a paddling pool....whilst I was grabbing the tools I met a plumber going into the next door property. The flood was so extensive the water had flowed through the mortar gaps in the party wall and the neighbours assumed they had a leak.

SandyLyon · 18 Apr 2019

Gasguru said:
if I'm forced to use it then copper olives and a smear of paste on the threads (to reduce friction) is the way to go.
.

Copper olives and a wrap or 3 of PTFE tape if required, you should keep jointing paste or any oil based products well away from plastic pipes / fittings.

durhamplumber · 19 Apr 2019

SandyLyon said:
Copper olives and a wrap or 3 of PTFE tape if required, you should keep jointing paste or any oil based products well away from plastic pipes / fittings.

Don't need tape either

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Compression fitting tightness on plastic pipe?

MJN

undertrained

dilalio

Gasguru

SandyLyon

durhamplumber

DIYnot Local

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