Shower trap advice

[ArranBennett]

Hi folks,

I am after a bit of advice please. Forgive terminology, I’m likely calling everything the wrong name.

I am replacing a:

Wirguin Twisto 90 (https://www.wirquin.co.uk/product/twisto-90-mm-plastic-dome/)

with a:

McAlpine ST90CP10-70 (https://mcalpineplumbing.com/traps/shower-traps-accessories/90mm-shallow-shower-trap-70mm-high/)

I have attached images of what I am working with. Does the waste pipe have an adapter from 1.5 inch to 40mm? The Wirguin is a 40mm compression fitting and the McAlpine is a 1.5 compression fitting.

1. Do I need to remove the adapter or can I get a coupling to connect the McAlpine to 40mm. I feel like that would save me a lot of bother.

2. The McAlpine comes with a bend coupling, so I’d be looking for a straight one with the 40mm compression fitting.

Thank you
Arran

 

[CountryFan]

40mm and 1.5” are the same, so you should be fine.

 

[ArranBennett]

Thank you for your reply. I hadn’t realised they were equivalent values.

What is the need for this thing on the end of the pipe then?

 

[Madrab]

When it comes to waste pipe, metric 40mm is the ID of the pipe, the OD is actually 43mm. 11/2" is the compression fitting dimension that is referenced in imperial but for all intents and purposes is the same.

What you have there will be the solvent weld adapter for the Wirquin trap which has altered the OD of the waste pipe from 43mm to 40mm which that trap is sized for. Try the compression end of the new trap onto that pipe and see if it'll fit and tighten up properly, if not then the reducer will need cut off and the and the waste pipe extended to meet up with the trap once it's on the tray waste outlet.

 

[ArranBennett]

Thanks guys.

The compression fitting does actually fit without needing to cut the solvent weld adapter off.

I reckon one of these might sort me out.

McAlpine T29 Compression Connection Straight Connector White 40mm x 38mm - Screwfix

Order online at Screwfix.com. Multifit straight connector with female thread. Can be fitted in domestic and commercial installations. Suitable for all plastic, copper and lead waste pipes. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

McAlpine recommend the bend they provide with the trap as the straight T29 is a more rigid connection. Unfortunately I don’t have the movement in the waste pipe to accommodate the bend.

 

[Madrab]

The bend that comes along with the trap allows a wide range of movement when it comes to waste runs and positioning - it also lends itself to there being an immediate fall out from the trap that allows the trap to maintain a high flow rate. If you are looking for a straight coupler out from the trap to do away with the bend then a T29-LN may work too, depends what the end is on the trap once you remove the bend but I believe they may be the same

 

[ArranBennett]

Just popping back to thank you for your help.
I have a working leak free shower trap.

I got myself the T29 and although I was able to compression fix straight on to the solvent weld adapter this did mean the waste pipe was too long. I cut the pipe right at the adapter, gave me a nice guide to cut with. The trap was then directly below the hole in the tray.

Best Wishes,
Arran

 

[CountryFan]

Just popping back to thank you for your help.

You’re most welcome

I have a working leak free shower trap.

Nice.