What fittings do I need to connect to my shower mixer and heads?

[Conor]

My plumbing expertise stops at anything involving threaded fittings, basically anything that's not push fit. i'm forced in to the position of having to fit our cross water two way valve mixer, shower head and hand shower.

 

All my pipework is 15mm PET. The valve box has threaded female brass ports:

 

They seem to be about 18-20mm internally. 3/4" BSP?

 

Blanking plugs that fit in to unused ports:

 

I just need the right fittings to get from that too 15mm pipe

 

Now, the shower arms. The are the same size thread as the ports. How do I fit these to the wall? A thin timber ground with backing nut? there's not much thread to work with and our stud build up is 18mm ply, 12.5mm PB, tanking, 12mm tiles. I'm thinking I'll need to put a strip of ply instead of PB

 

 

Edited December 23, 2021 by Conor

[Onoff]

Those fittings are 1/2" BSP.

 

Does this help

 

 

[Conor]

Perfect. So can I assume mine is 3/4"? SO just need the wall plate elbows, short section of 22mm pipe then reduce to 15mm? I've already pulled the 15mm pipework through the studs so that can't change at this stage.

[Onoff]

I used compression fittings:

 

 

 

I did 20 turns of tape and a smear of goop (Jet Blue Plus)  on top of the tape. That's the 1/2" male into the valve.

 

On the 15mm compression I did just a smear of goop around the seat in the brass (with the pipe in) but before the olive sits down.  Then seat the olive, then more goop after round the outside of that.

 

Pays to put your tape on the right way!

 

 

 

 

 

[Onoff]

2 minutes ago, Conor said:

Perfect. So can I assume mine is 3/4"? SO just need the wall plate elbows, short section of 22mm pipe then reduce to 15mm? I've already pulled the 15mm pipework through the studs so that can't change at this stage.

 

[Conor]

So, looks like 1/2" thread. Makes things easier.

 

Would these work?

 

https://www.screwfix.com/p/hep2o-plastic-push-fit-adapting-male-coupler-15mm-x/5970f

 

 

[markc]

4 minutes ago, Conor said:

So, looks like 1/2" thread. Makes things easier.

 

Would these work?

 

https://www.screwfix.com/p/hep2o-plastic-push-fit-adapting-male-coupler-15mm-x/5970f

 

 

Yes they will be ideal if you already use Hep20

[Onoff]

10 minutes ago, Conor said:

So, looks like 1/2" thread. Makes things easier.

 

Would these work?

 

https://www.screwfix.com/p/hep2o-plastic-push-fit-adapting-male-coupler-15mm-x/5970f

 

 

 

Yes, they'll take 15mm copper too but be sure the ends are clean and no burrs. With plastic pipe you need inserts.

[Iceverge]

3 hours ago, Conor said:

So, looks like 1/2" thread. Makes things easier.

 

Would these work?

 

https://www.screwfix.com/p/hep2o-plastic-push-fit-adapting-male-coupler-15mm-x/5970f

 

 

 

Yes. Get everything back to Hep2o as soon as possible in my opinion. 

 

Recently having played with these exact fittings I would recommended getting a hacksaw blade and roughening up the thread of the male insert, much like the blanking plug that you took out.  Then using something more fibrous than MDPE tape to wrap the threads before screwing them together. Hemp + Boss White or Loctite Pipe Sealing Cord both worked fine for me. 

 

I failed to make a few joints seal brass to brass with MDPE alone. 

 

I did use 22mm compression fittings with Hep2O and an insert too without problems. 

[Nickfromwales]

3 hours ago, Conor said:

So, looks like 1/2" thread. Makes things easier.

 

Would these work?

 

https://www.screwfix.com/p/hep2o-plastic-push-fit-adapting-male-coupler-15mm-x/5970f

 

 

I use those a lot. Very robust and reliable, and a perfect partner with Hep2o ( Wavin - Hepworth ) pipework. 

[Nickfromwales]

2 minutes ago, Iceverge said:

I did use 22mm compression fittings with Hep2O and an insert too without problems. 

I never put push of it into compression, as it’s a plastic pipe which a metal olive then bites down into. Insert just makes the plastic pipe stay rigid, and does nothing to prevent the olive sinking into the plastic.
Never ever done this on a plumbing job, unless it was a temporary setup like a filling loop etc that I needed to cobble together in a rush which I then babysat whilst in use. I would never do this as a permanent job, and recommend the use of a push fit fitting into copper pipe for every single instance where you need to transition from compression to push fit. 

[Iceverge]

Eeeeekk...... 

 

I was working on the principal that less joints were better. 

 

I have 5 of these. All accessible. It's been about a month. All ok so far. I'll keep an eye on it. 

[Conor]

Job done. Phase 1 anyway.

 

 

[Conor]

Next question. This is the hand shower and the wall plate elbow. I'm assuming the shower fitting will have to be fully tightened in to the elbow fitting for it to be sealed? So then I'd need to get the positioning of the elbow exactly right?

[Onoff]

11 minutes ago, Conor said:

Next question. This is the hand shower and the wall plate elbow. I'm assuming the shower fitting will have to be fully tightened in to the elbow fitting for it to be sealed? So then I'd need to get the positioning of the elbow exactly right?

 

See page 46 of my mega thread and what @Nickfromwales said on Jan 14:

 

 

 

[markocosic]

Why not use compression onto plastic pipe @Nickfromwales?

 

I've used this (with soft copper olives not the useless brass ones usually supplied) everywhere I've filled from 15 mm pex to copper for radiators...

 

PTFE tape is naff IMO. Loctite 55 every time; after roughing up the threads first. Much more forgiving of how far you turn it up.

[Iceverge]

When you tube told me PTFE was a lubricant rather than a sealing tape a penny dropped. 

 

Roughing the threads made all the difference for metal to metal.

 

"Peel it like an apple" the man said!