Compression fitting size for mains inlet (photos attached)

[shd1970]

As mentioned on another post, i'm looking to replace my stopcock and simplify the pipework too so my new kitchen units fit easier
I have attached 2 photos....one is my current stopcock and the other is the pipework from my neighbour who as you can see, have attached a compression type fitting to the main black plastic inlet pipe. As you see, it fits nicely under the kitchen sink unit.

Can anyone confirm if that compression fitting is *anything special* please and also, what size it is ?
Would it be a standard 22mm/15mm reducer with the appropriate olives fitted, and use PTFE on the threads and olives ?

I've tried to measure it with a tape measure and it looks like 21mm (it might be my eyes !) so not sure if it is actually a different size, what with it being 30+ years old

Additionally, is there anything else i need to consider, what with it being the main inlet to the house ?

Thanks in advance

 

[Elkato531]

Probably 3/4" black alkathene. A 22mm compression fitting with a 3/4" olive should do the job. Ideally the pipe should also have an insert. If you can get the old insert out, you may be able to use that. Also think you may be able to tap a short bit of 15mm into the end to act as an insert but I may just have made that up. Can't remember.

Don't put PTFE on the threads as it won't do anything. A couple of wraps on the olive if you like.

 

[DursleyDonkey]

I had something very similar in my last house. Black plastic pipe of a bit less than 22 mm diameter. I wanted to change from 15 to 22 mm stopcock. I found that the existing nut and olive on the plastic pipe was a perfect fit on the new stopcock, so no messing around with inserts or new olives. You might be as lucky.

 

[shd1970]

Ideally the pipe should also have an insert.

An insert ?

for what purpose....to keep the pipe true and prevent it from being distorted i assume ?

 

[Hugh Jaleak]

Inserts strengthen the pipe. Compression fittings are just that, they compress the olive onto the pipe to make the seal, copper has the strength to stay rigid, plastic as you say, can distort, and the joint fail.

 

[shd1970]

I just noticed what looks like a similar thread and user "Charnwood" seems to be suggesting a "Philmac" do these couplings

https://www.diynot.com/diy/threads/incoming-watermain.279136/

Is this what i'm looking for, as i'd rather not have to take it apart to then go hunting around for parts ??

 

[Hot&Cold]

in your first photo there is info stamped on the nut,says size it could be 22mm,your neighbours fitting looks like there is a possibility of it is leaking water.If not done correct the connection can pop off .
Edit.
This previous diynot thread https://www.diynot.com/diy/threads/black-22mm-plastic-pipe-insert-required.220234/

 

[shd1970]

in your first photo there is info stamped on the nut,says size it could be 22mm,your neighbours fitting looks like there is a possibility of it is leaking water.If not done correct the connection can pop off .
Edit.
This previous diynot thread https://www.diynot.com/diy/threads/black-22mm-plastic-pipe-insert-required.220234/

Thanks for the link Old&Cold

I can't see any sizes on my nuts (ooo err ) from the photo but agree that there is something stamped on my neighbours

so to summarise :

1 - it looks like all i need is a standard 22mm/15mm compression reducer (straight or an elbow), but with a 3/4 olive and using a 15mm piece of pipe as an insert......correct ?
2 - olive...brass or copper ?
3 - anything special required to cut the black pipe or will a 22mm copper pipe cutter cut it, or just use a hacksaw and clean up/keep it nice and straight ?
4 - PTFE on the threads, on the olive or both ?

Thanks again to all who have responded so far....mucho appreciatio !

 

[Hot&Cold]

1.use an olive that fits snugly over the black pipe,could be metric or imperial.
2.brass.
3.hacksaw with a new blade.
4.Make the join on the black pipe (nice and tight) then undo it and apply ptfe tape around the olive mating surface in between the chosen fitting.its just to compensate if the olive has embedded unevenly into the black pipe.