15mm Olives On 1/2" Pipe Question

[plumbandplumber]

Need to ask another question from the experts on here. A year ago, I added an iso. valve to the pipe under a tap. The pipe is old 1/2" and the olives were the copper ones that came with the new valve.



At the time, I remember that I had to tighten the compression nuts quite a bit as there was a slight weep on both.Yesterday, I had to remove one of the pipes that connects to one end of the iso. valve. I was surprised that the olive wasn't even slightly tight on the pipe, and when I slid the compression nut off the end of the pipe, the olive slid off too and I had to get it out from the inside of the nut.


So, should I be using 15mm olives on imperial pipe? Why didn't the olive compress onto the pipe?
I'm surprised the olives sealed at all. Maybe it was only my habit of putting a smear of Boss White on all olives that made them seal.

 

[GasmanxxxR1]

1/2" is bigger than 15mm osd. So seems weird that it wouldn't tighten

 

[turnpin]

Maybe brass olives not copper ones?...regards Turnpin:crazy:

 

[josh]

Copper olives are better, usually get away with 15mm olives on 1/2'' tho but wont on 3/4'' using 22mm olives.

 

[Best]

You probably didn't tighten the valve enough. The paste should have helped greatly to tighten it as less friction & no squeal usually. Paste (Jet Lube I prefer) is IMO always needed & a better joint.
Copper olives commonly will not bite into the pipe & the fact that it was old 1/2" pipe means the old pipe is thicker & stronger than modern stuff & the olive will easily pull off later.
Remember that the olive will be very tight to the pipe WHILE it tightened inside the valve/fitting.
Brass olives IMO are better than copper in a lot of ways, providing they are good quality & not too hard. Brass olives will not weep on heating pipes but copper tend to slightly eventually as they are softer.

 

[SimonG]

Copper olives are better, usually get away with 15mm olives on 1/2'' tho but wont on 3/4'' using 22mm olives.

Course you can. At a push. Paste and ptfe.

 

[josh]

Course you can. At a push. Paste and ptfe.

to loose for my likeing, also tried soldering a normal socket on once and it just wouldn't have it.

 

[MisterB]

I wouldn't ever use ptfe/paste to make a permanent fix, re 3/4 olives, it wont last and is asking for trouble long term - though of course someone will come along and quote a joint never failing in 20 years!!! use a proper 3/4 to 22m fitting OR get a 3/4 olive (its been a while, so I don't know if you can buy them - BUT next time you rip some old pipe out, it might be worth salvaging any 3/4 inch olives)

15mm olives should be fine on 1/2 inch pipe

 

[brum]

BES sell3/4 olives

 

[kay-jay]

You probably didn't tighten the valve enough. The paste should have helped greatly to tighten it as less friction & no squeal usually. Paste (Jet Lube I prefer) is IMO always needed & a better joint.
Copper olives commonly will not bite into the pipe & the fact that it was old 1/2" pipe means the old pipe is thicker & stronger than modern stuff & the olive will easily pull off later.
Remember that the olive will be very tight to the pipe WHILE it tightened inside the valve/fitting.
Brass olives IMO are better than copper in a lot of ways, providing they are good quality & not too hard. Brass olives will not weep on heating pipes but copper tend to slightly eventually as they are softer.

Copper olives should never be used on heating pipes. Yes it is softer then brass but the reason is because it has more thermal expansion than brass which can cause weeping on hot pipes

 

[galaxy_plumbing]

got loads of 3/4 inch, no 1/2 inch olives however