speedfit additions to existing copper piped system

[lymmranger]

Hi guys,

I am currently refurbishing the bathroom due to a cracked shower tray

my problem is with the pipework to the shower. The original shower mixer was fed by 22mm pipe, pressurised by a twin 3bar pump. The new mixer requires 15mm fittings so I intend to cut back the existing pipework and add isolators (currently none are fitted) my problem is that it will be really difficult to do this in copper due to a combination of tight access and risk of incinerating the bath, so I am looking at using plastic speedfit (JG of course) my worry is 15mm plastic has a much smaller internal diameter to copper tube will it be ok?

plan is/was
- cut through 22mm pipe and add 22mm to 15mm reducer, then add isolator then run pipe up stud wall to mixer valve

is this ok?

 

[bengasman]

yes

 

[kevplumb]

sounds ok

make sure you use full bore isolation valves tho and don't forget the inserts for the pipe

 

[bengasman]

You're getting slow Mr. 400.

 

[lymmranger]

cool - that was easy

...time to go shopping!!!

I used Hep2O on a narrow boat years ago so am quite happy using it and yes whilst doing that I learned to check very carefully that the insert was indeed present!

 

[Whitespirit66]

I used Hep2O on a narrow boat years ago so am quite happy using it and yes whilst doing that I learned to check very carefully that the insert was indeed present!

Yes, you'll only do it once!

 

[lymmranger]

Blimey dropped to page 5 so quickly!

still nervous about this (not doing it but the huge reduction in bore!)

My plan is a JG 22mm to 15mm reducer straight on to the copper 22mm pipe.
It will then (via a JG elbow) rise above the floorboards and have the isolator fitted before rising up the stud wall to the shower mixer

...kevplumb mentioned full bore isolators, as this is behind an access panel (i.e. out of normal vision) can I use the emergency stop valves? because I cannot see that JG do a full bore isolator and using a stop valve would also make the pipework safe from leaks until I make final connections after tiling.

Finally my shower mixer has chrome tails which can either hang down or be turned to go through the wall which is easiest to couple bearing in mind JG fittings do not like chrome pipes