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[KittenKong]

So we have pipes under the kitchen sink… the ones sticking out of the wall and imperial and the ones connecting onto that are metric. Of course they don’t quite fit 🙄.

So we have a leak and was wondering if there are connectors that are one measure one end and the other at the other. Genius idea.

So how do I measure the pipe - is it diameter or circumference? Do these things work, should I get the metal ones or the rubbery versions? The last time it happened the plumber wrapped some string around the smaller pipe and that did a ‘quick fix’ (I’ve only just discovered this).

💧 💦 🚰 🌊🏊‍♀️🦆

You need to @PigletJohn

What? @PigletJohn isn’t hanging around here? 🤣

The pipe will be measured by diameter. But that's as far as my knowledge extends I'm afraid!

imperial pipes are measured by the internal diameter; or in some cases what the intrenal diameter used to be before the metal of the pipe was made thinner to reduce costs

metric pipes are measured by the external diameter.

the result is that a 1/2" copper pipe is the same size as a 15mm copper pipe, and the same fittings will fit it.

3/4"copper is almost the same size as 20mm copper, but you can use a copper olive to take up the difference or do other nefarious tricks. PTFE tape will take up a little slack in compression joints

28mm is not quite same size as one inch.

however you can get adaptors that fit imperial on one end and metric on the other

example

you will not be able to solder wet pipes so you will need a brass compression fitting.

what size is your pipework, and is it copper, steel, lead, black plastic or blue plastic; or grey or white plastic.

What is the thing that is leaking? show us a pic

So one side is metal and the new pipe is plastic. The bit dangling down is the string…

So whilst we wait… dinner suggestions for a sinkless kitchen?

www.amazon.co.uk/Flexible-Adaptor-Suit-50mm-40mm/dp/B01D4RV4OG/ref=mp_s_a_1_4?crid=33JQ75LAEB6O6&keywords=sink+imperial+to+metric+pipe+connector&qid=1659884083&sprefix=sink+imperial+to+metric+pipe+connector+%2Caps%2C50&sr=8-4

would this work?

Dominos 😁

"3/4"copper is almost the same size as 20mm copper,"

22mm copper, I mean.

20mm is a blue plastic size

it,s a plastic waste pipe, then.

take a wider pic.

in your case, I don't think it's a metric/imperial problem.

i think it's a "two different manufacturers not quite the same" problem.

or perhaps it is off centre or cross threaded

Is that better? The plastic bit is the u bend.

is the second picture the right way up?

how old is the house?

where dose the pipe go, on the other side of the wall?

is it iron?

stand back a bit so you can take a wider pic

This better? It’s a 1950s build.

The concertina light grey pipe at the back is for the dishwasher.

the plastic fitting that goes onto the metal pipe is I think a compression fitting with a rubber ring inside that squashes down onto the pipe and will accomodate quite a lot of size mismatch.

it looks to me like the trouble is that the conglomeration of pipes is tilted so it does not connect straight on.

It looks to me like you need to cut half an inch or so off a pipe, to get the set upright so it can push onto the metal pipe and screw tightly. probably the horizontal of the "L" coming off the sink. If that can be done without cutting off anything that makes the seal. It may have a conical plastic washer that you can push back.

it can be done with a hacksaw.

If you want, you can undo the compression nuts (use rubber gloves for improved grip) and try to line them up then retighten.

the nut is not supposed to be a seal, so wrapping hemp round the thread is doomed to failure. The seal is the rubber ring inside that should be tight round the metal pipe.

or you can put a bucket under it and call for a better plumber.

you did not say where the pipe goes on the other side of the wall. Maybe you can pull it out and renew in plastic.

Other side of the wall… hmmm that’s the bathroom. Walls are all thick concrete so it’s a mystery to me!

then it might go into a plumning duct and a soilpipe, or it might go into a hopper

the hopper is easier to replace.

Was this DIY?
I think the connections aren’t straight that’s why they are leaking. The PTFE tape will only add to the problem in this situation.

I’d unscrew the elbow between the the U bend and the metal pipe and completely the PTFE tape from both ends.

Refit the elbow into the U bend
use this: www.screwfix.com/p/mcalpine-flexcon6-flexible-waste-pipe-fitting-white-40-x-210mm/9808v

And make the connection between the elbow and metal pipe.

You may need to swivel the u bend around to make room for the flexi.
Doesnt look great but will do the job.

No it certainly was not! We actually paid someone to do it! If it was DIY it would have been absolutely straight (I’m pretty anal about things lining up)