Waste pipe sizes

[Winston]

Why is it that 40mm 11/2 solvent weld pipe is actually o/d of 43mm and also different to pushfit and compression pipe?

Was installing a washing machine and dishwasher yesterday and I think the merchant has mistakenly given me the wrong part. As I have not been able to afford diamond core cutters I used a existing hole in the wall which was for 32mm pushfit.

So used 32mm solvent weld and went to get my 32/40 solvent weld adaptor but it didnt fit! It would fit the 32mm but not the 40mm. So in the end fitted 32mm then had to go and get a 40mm compression coupling and tighten up real tight then go to 40mm!

Am I missing something apart from a few brain cells?

 

[bathroomboy]

Hi Winston, as you have found solvent weld is a different diameter to pushfit, I use a lot of solvent weld especially in bathrooms where in the future it is not accessable, it is not going to leak, in situations as you describe where you have to join the two, it has to be done using a universal compression joint, hope this helps.

 

[johnmcginty]

I know what you mean , thats why I always have the outlay in the van which is mainly compression fittings which fit both abs and pvc.

 

[Winston]

Thanks guys was just hoping to avoid the compression as it so much bulkier and the risk of leaks, still dont get why the 32mm to 40 solvent weld converter didnt fit my pipe as I only use solvent weld other than traps!

And late Saturday afternoon isnt the best time going to find stuff in diy shops espesially when doing a job on a mates rate!

 

[Bernie2]

Hi! Winston

When plastic first came out not even the makes would interchange. The 42mm could be a variety of sizes. It was a bit of a nightmare. If using solvent weld we often warmed he end up of the larger and sleeved it over the smaller. But as you say you can't do that with a 32mm - 42mm adaptor. The only answer seems to be as the others say, a compression fitting and I must admit that is what we used when they came out.

But even here you have got to be careful as some compression fittings are sloppy on the smaller sizes and you have to change the back nut, plastic ring and olive for smaller size's. Some compression fittings have an internal inner sleeve so you can't do that and some don't which you can.

Its all challenging.

 

[Winston]

Yer very challanging just hope it all sealed ok as done it on mates rate who has a new tenant wasnt expecting 3 hours work for £80 Including materials!

And another thing why is it you cant buy 32mm or 40mm solvent weld equal tee it would be very useful providing you incorpurate a non return on the wastes.

 

[Plouasne]

I had a batch of Key Terrain fittings, the old 11/2" size I think now, its going back over 25 years, and the tube would not fit into the fitting, Key's answer when I rung them, was that both were in tolerance, but (and here's the rub), the tube might have come from an old worn extruding machine, just in tolerance, and the fittings might have come from a new machine, with a tight margin before it wore into size

 

[Winston]

What about standards surely all these manufactures must have the common sense to have quality assurance in place and even possibly talk to other manus to get a standardisation throughout industry!

 

[Plouasne]

Don't get me started The UK could not organise the proverbial p**s up in a brewery, I would hate to think what would happen in a "knocking shop", plastic pipe manufacturers wanted to keep you to their products when plastic first came out, hence the non standard sizes
They also missed the boat by miles the chance to export fittings when they did a B******ised metrication of sizes, and just changed the size name from imperial to metric, nothing apart from 22mm copper fits anything on the continent, with the exception of steel tube for water and BSP thread sizes

 

[Winston]

It will get me started what is it with this country it's like all the pakaging with everything now that must be 80% of the cost then you need a knife to get into it

How hard can it be for them to jig machines up to be able to provide a standard size and of useable quality, it would be like me going in front of the dragons saying I have invented a square wheel! Or a bag with no bottom to it!