Install the app
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

Illuminate

illuminate
Jan 8, 2021
75
5
8
BS24 8EW
Member Type
General Plumber
I am having to work on a concealed shower but there is no service valve and so I am having to isolate from a large mixing valve which is linked to several other showers. I am going to add a service valve to make it easier for future maintenance but the pipe connected to the shower is 15mm plastic and I have a compression service valve. I don't like using compression on plastic and so am planning to put the service valve onto copper and have a hep coupling on each end to just fix it onto the plastic pipe but I was worried that the high pressure system with a very large pump would cause the hep coupling to burst. Please can anyone enlighten me and give me the reassurance I need?
 
If there’s a blending valve probably Mira no point in putting a shower in best to stick with existing probably push / time accessories with fixed heads

There should be valves before the blending valve
 
  • Like
Reactions: Illuminate
If there’s a blending valve probably Mira no point in putting a shower in best to stick with existing probably push / time accessories with fixed heads

There should be valves before the blending valve
Thanks foe your reply, I did not explain correctly, I am keeping existing lush button but I need to change the push button itself. Strangely, there is no isolation before the mixing valve, I looked really well, following pipe route and I went further along the other side of mixing valve on both hot and cold pipes. Unusual that the original plumber hadn't added this.

Even though the water would be much below 95 degrees after being mixed, I'd rather not risk it like what you are hinting as I would be worried in the event of the mixing valve failing.

A lot of the other pipe routes to the other showers have compression ball valve isolations but like I said, I had compressing onto plastic, though it is a swimming pool area and so the main damage is a leak would be the cheap office style ceiling (whatever you call it) abd it would only weap from a compression at worst. But probably best foe me to just leave as it is and again isolate the mixing valve when they are closed.

Any further tips would be appreciated, appologies to go on.
 
https://www.NoLinkingToThis/p/hep2o-hx22-15ws-ball-valve-15mm/1375f
So this can withstand high pressure or is it the same as a standard hep fitting. Looking online it says 18 bar but does not specify the bar at different temperatures and I would be surprised if it could withstand 18 bar of pressure at high temperature.

Any help welcome?
 
Your probably over thinking this.
As current pipework is plastic and and has been/is working OK logic would suggest its within design criteria.
Have you actually tested pressure and water temperature?
 
  • Like
Reactions: Illuminate
I agree, you’re way over thinking this.

Cut pipe, add two inserts, install compression lever valve. And if possible clip the pipe either side of the valve.

Transitioning to copper just adds 2 more potential leak joints.

I can’t remember the last time I’ve seen a compression on plastic leaking, however, compression on copper? A couple of hours ago.

The olive compresses the plastic pipe and creates a great seal.
 
  • Like
Reactions: Illuminate

Official Sponsors of Plumbers Talk

Similar plumbing topics

We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.