32mm basin trap, but 40mm bath trap

[jrtrrror]

Hi all.
I'm just curious...why do bath traps use 40mm connections and pipework and yet basin traps use 32mm?

I have a very short length (1.25m) of 40mm pipe leading from the bath into the soil pipe. Half way along this run, I have a 40mm 't' connector, from which the pipework from the basin connects. But the basin has a 32mm trap. How do you connect the 32mm trap to the 40mm pipework?

Are you allowed to do so?

I've seen this...

https://www.NoLinkingToThis/p/mcalpine-st28m-straight-connector-white-32mm-x-40mm/95260

 

[ShaunCorbs]

Because of the water volume

Use a tee with a reducer eg 40mm tee and a 40-32mm reducer

 

[jrtrrror]

Because of the water volume

Use a tee with a reducer eg 40mm tee and a 40-32mm reducer

Hi ShaunCorb.
Are you referring to two separate items?
If you are referring to just one connector, I can't seem to find a 40mm tee connector that has a 32mm inlet at the top of it.
What would I type into Google?
Ta

 

[jrtrrror]

Hi ShaunCorb.
Are you referring to two separate items?
If you are referring to just one connector, I can't seem to find a 40mm tee connector that has a 32mm inlet at the top of it.
What would I type into Google?
Ta

I'm just wondering if you mean use a 40mm equal tee and a separate connector, more specifically a 'push fit' reducer 40mm to 32mm screwed into the top of the tee. And then replace the existing 40mm vertical pipe that leads from the 32mm basin trap, with 32mm piping that will 'push' into the top of the 'push fit' 40mm to 32mm reducer.
Is that correct?

 

[ShaunCorbs]

https://www.NoLinkingToThis/p/floplast-equal-tees-white-40mm-3-pack/99915

https://www.NoLinkingToThis/p/floplast-reducers-40-x-32mm-white-5-pack/63577