Parts to go from 42mm sink to 25mm pipes?

[james2]

I have a sink with a 42mm threaded outlet on it and need to connect that to a ~25mm outlet pipe that's already installed. The outlet pipe has a female threaded end on it, but this could be chopped off if needed. The space between the sink and the current end of the pipe is 

 

Can't find a single adaptor/reducer that does this, and I don't want to bodge it as this is the repair for the previous bodge.

 

Pic attached. The space between the two ends is only about 4 or 5 cm, but I s'pose current end could be cut off the outlet pipe to make more space. 

 

Thanks for any ideas/part suggestions

 

J

Edited August 4, 2022 by james2

[Alan de Enfield]

Something like this - several types on ebay. 

Just put 42mm to 25mm hose adapter into google.

 

 

 

 

Maybe even something like this :

 

Edited August 4, 2022 by Alan de Enfield

[james2]

2 minutes ago, Alan de Enfield said:

Something like this - several types on ebay. 

Just put 42mm to 25mm hose adapter into google.

 

 

 

Thanks for the reply but posting as I have spent a while searching all the usual places and can't find anything that does it. Links to specific parts that'll help me much appreciated. "42mm to 25mm hose adapter" doesnt have any useful hits that I can see

[Rob-M]

Can't remember the exact sizes we needed but we went to a plumbers merchant and they supplied a few adapters that fitted together to go from the waste pipe to the sink when we were putting a new sink in.

[Jen-in-Wellies]

That 42mm OD thread on the sink waste is actually a 1,1/4" BSP thread. 1,1/4" does not equal 42mm, I know, but BSP threads are weird like that. You need a 1,1/4" BSP to 25mm hose tail adaptor, or whatever internal diameter that green corrugated hose is. Get some more hose to meet the adaptor. An example. Not the best price, I'm sure, but it can be done with just one fitting.

The green hose will probably also be an imperial size. Could be 1" (~25mm) bore, or 3/4" (~19mm), can't tell from the pictures.

Jen.

Edited August 4, 2022 by Jen-in-Wellies

[james2]

6 minutes ago, Jen-in-Wellies said:

That 42mm OD thread on the sink waste is actually a 1,1/4" BSP thread. 1,1/4" does not equal 42mm, I know, but BSP threads are weird like that. You need a 1,1/4" BSP to 25mm hose tail adaptor, or whatever internal diameter that green corrugated hose is. Get some more hose to meet the adaptor. An example. Not the best price, I'm sure, but it can be done with just one fitting.

Jen.

 

oh my gosh - thank you so much - as usual just knowing the right terms (in this case seems like '1 1/4" bsp' and 'hose tail' really helped the googles) makes alllll the difference. i think this will sort me out! now to try and get one quickly!

 

[David Mack]

15 minutes ago, Jen-in-Wellies said:

That 42mm OD thread on the sink waste is actually a 1,1/4" BSP thread. 1,1/4" does not equal 42mm, I know, but BSP threads are weird like that.

Plumbing threads are almost always bsp pipe sizes. Wikipedia has a useful table giving the key thread dimensions in imperial and metric units.

[dmr]

I believe that in BSP (British Standard Pipe?) the size refers to the diameter of the hole rather than the size of the thread. The logic/justification is that plumbers are more concerned about the hole size, and hence flow capacity, than they are about thread size. I have yet to meet this plumber 😀

[David Mack]

21 minutes ago, dmr said:

I believe that in BSP (British Standard Pipe?) the size refers to the diameter of the hole rather than the size of the thread. T

My understanding is that it related to the internal diameter of the pipe using the rather thicker walled iron pipe in use at the time. Since modern steel pipe has a thinner wall thickness, the actual nternal diameter is somewhat greater than the nominal pipe size.