Replacing MDPE x Copper stop valve

[ChrisOxford]

Hi everyone,

My parents' house was built 20 years ago, the incoming water pipe is blue plastic (MDPE?), and the rest of the system 15mm copper.

The main stop valve hasn't been touched in 20 years and is well and truly seized. It's cheap and nasty too and I think I'd be better replacing it rather than trying to repair. Fortunately, I can switch off the water at the meter on the pavement.

I've changed all-copper stop valves before, but never worked with plastic.

Is this an easy DIY job?

How do I measure the plastic pipe? As simple as just the outer diameter? I presume it will have an insert which I can re-use. Will there be an olive which I can re-use too? Is a bit of Fernox LS-X or similar in order on plastic?

Cheers,

Chris.

 

[Phill Peck]

Probably 25mm yes it's the outside diameter

You'll get a 25x15 or 25x22 stoptap from any plumbers merchant.

Existing nut and olive should fit maybe a wrap of ptfe

Personally I'd go 25x22 then reduce down. Just incase they want a better flow of the main in future (unvented cyl/combi)

 

[ChrisOxford]

Fantastic, will give it a go now.

Chris.

 

[Phill Peck]

Measure it first though