McAlpine 90mm Shower Trap Installation

[leccyblue]

Hi All,

I've bought this trap today https://www.wickes.co.uk/McAlpine-ST90CP10-70---Shower-Trap---Chrome---38mm/p/118624

I chose it based on the fact the internals completely disassemble for cleaning. Our existing trap doesn't, just has a removable basket and is a total pain to clean when required once or twice a month.

However I'm a bit confused by the 1.5" 'multi adapter' that comes with it. It creates a bend (I think 135 degrees) in the pipe which can be rotated to face any direction. I had assumed I could discard this and pipe straight into the compression fitting on the side of the trap, however I don't think this is possible as the internal diameter of this fitting is 39-40mm which won't accept the 40mm solvent weld pipe I am using (OD circa 43mm)

Ideally I don't want to introduce a bend as my pipe run needs to be straight. Is there some sort of adapter I can buy to fit solvent weld straight into the compression fitting on the side of the trap? Ideally it needs a collar on it so the nut can pull it in tight.

Another option would be to use another 135 degree bend to return the pipe to straight. Is it within spec to do this or must the bend remain for any reason?

I was going to email McAlpine but their contact page states they don't accept installation queries from the general public.

Any advice appreciated

Thanks

 

[Deleted member 267285]

There doesn't seem to be one, but McAlpine would know better. I've checked the instructions and they state using the multi fit - defined as either sized waste pipe. You may find this one better suited or introduce a 135? ST90CP10-53

 

[Madrab]

Not sure of the connection but one of these might fit.

One tip .... never finalise your pipe run until everything is in place and joined together

 

[lostinthelight]

Hi All,

I've bought this trap today https://www.wickes.co.uk/McAlpine-ST90CP10-70---Shower-Trap---Chrome---38mm/p/118624



I was going to email McAlpine but their contact page states they don't accept installation queries from the general public.

Any advice appreciated

Thanks

Dont be put off by that, what you are doing is making a prepurchase /product suitability enquiry by asking if the outlet will accept 40mm solvent pipe.

 

[foxhole]

Stick a 45 on it and it’s then straight .

 

[leccyblue]

Thanks for the replies everyone!

TheNovice - I did actually consider the -53 variant of the trap, however it has a shallower water seal and the inside is the basket type like our existing one, they're a sod to clean. I thought (wrongly) the -70 variant I purchased would accept 40mm solvent weld pipe into the compression fitting so bought it based on it's other merits!

Foxhole - yes, I'm happy to use another 135/45 angle if necessary however it will offset the pipe run a bit. It should still be within my studs but I'd need to dry assemble to test.

I have found this https://mcalpineplumbing.com/sites/default/files/uploads/drawings/MT18L.pdf on the McAlpine site which I think will do the trick? It doesn't have a collar on the 40mm end that goes into the trap nut but that's not the end of the world.

I'll see if anywhere locally stocks them!

 

[foxhole]

Won’t offset , two joints will achieve every angle from 90 to 180 ie straight .

 

[leccyblue]

I can't see how it wouldn't offset? I will have a straight pipe run but it will be an inch or so north / south of the original trap outlet? I'd need to 3 x 135/45 adapters in a row to bring it back offset!

Anyhow, I messaged McAlpine in the end and pretended to be a plumber and they've got a better solution in the T29, it's a 1.5" female BSP thread to 40mm multifit, which is possibly similar to what madrab was suggesting - https://www.screwfix.com/p/mcalpine...tor-white-40mm-x-38mm/328hr?_requestid=439236

I have ordered one ready for collection tomorrow

Thanks for everyone's replies!

 

[lostinthelight]

Did they say about sealing the threads between the two, Ive not seen it done with one of those before.

 

[leccyblue]

Did they say about sealing the threads between the two, Ive not seen it done with one of those before.

Hi, they didn't no - but the image on their site (https://mcalpineplumbing.com/plasti...raight-connector-multifit-x-bsp-female-thread) shows a rubber washer on the female BSP thread, which should butt up nicely to the end of the male BSP on the trap creating a watertight seal. I'll test it before I commit to the permanent installation but it looks as though it will be OK?

 

[lostinthelight]

Thanks Id not seen the internal seal so everything should be good to go

 

[John D v2.0]

You can often mix and match parts on mcalpine traps if you need a part that they don't stock anywhere at a reasonable price., I was going to do the same as you on our shower but in the end i had enough space to rotate the trap 45 degrees and still have the straight run after that.
Bends are not a big problem closer to the trap for clearing if that's what you're concerned about, you can easily get a flexible snake around them.

 

[leccyblue]

Thanks John. Rotating it 45 degrees might still be an option but it will put it very close to the joist which could make future disassembly/replacement more difficult.

I've got the T29 adapter now and it fits perfectly. The only concern is that the rubber washer creates a bit of a lip on the inside of the joint, which might trap debris. But as you say, that part is easily accessed from inside the trap, especially with this trap as the whole internals come apart.

I'm happy now

Thanks everyone for all the help and I hope this thread helps someone else out in the future!