Connecting toilet that has a 15mm connection, not 1/2inch

[phatboy]

Hi,

I have a new Duravit concealed back-to-wall toilet. It has a 15mm supply connection, not a 1/2" (Experience so far was European items still use 1/2). I say 15mm, the nut from a 15mm elbow fits it perfectly, but of course measuring it is something like 19mm.

The other end is a Hep2O 15mm push fit socket, coming out of the wall behind the toilet. Can anyone help with the best way to hook this up? I'm fairly new to plumbing and get caught out with fitting sizes.

Thanks!

 

[Scally-Ho]

15mm is a diameter of a Uk copper or plastic plumbing pipe size that took over from imperial 1/2". Whilst with compression, both are interchangeable, but with capillary and adaptor from one to the other will be required unless of course you are an older plumber with nouse. and knows the workaround. If your back-to-wall jobbie has a connection that is 1/2BSP threaded, then all you need is an iron to copper fitting.
Supply some photo then we'll all know what we are contending with.

 

[phatboy]

15mm is a diameter of a Uk copper or plastic plumbing pipe size that took over from imperial 1/2". Whilst with compression, both are interchangeable, but with capillary and adaptor from one to the other will be required unless of course you are an older plumber with nouse. and knows the workaround. If your back-to-wall jobbie has a connection that is 1/2BSP threaded, then all you need is an iron to copper fitting.
Supply some photo then we'll all know what we are contending with.

The cistern doesn't have a 1/2BSP, I tried one of them, slightly too small. But the nut from a 15mm compression elbow fitted perfectly.

Not there to get a picture today sadly, but 1/2 and 15mm look the same? The cistern has a 15mm thread coming from the bottom, and coming out of the wall is this: https://www.screwfix.com/p/hep2o-plastic-push-fit-equal-90-elbow-15mm/5295f

Hope that helps?

 

[Exedon]

Unless you have something really ancient 15mm compression nuts are threaded 1/2 in BSP.

 

[avonmouth]

15mm is a diameter of a Uk copper or plastic plumbing pipe size that took over from imperial 1/2". Whilst with compression, both are interchangeable, but with capillary and adaptor from one to the other will be required unless of course you are an older plumber with nouse. and knows the workaround. If your back-to-wall jobbie has a connection that is 1/2BSP threaded, then all you need is an iron to copper fitting.
Supply some photo then we'll all know what we are contending with.

15mm fittings are the same as 1/2 inch and will fit either size.It is only 22 and 28mm where you would need a different fitting.

 

[Madrab]

We were always taught it was to do with Internal Diameter (ID) and Outside Diameter (OD). Imperial was always measured in ID sizes so with the pipe wall thickness 1/2” ends up slightly larger than 15mm but will fit 15mm compression. When it comes to 3/4” pipe though it only reaches a bit over 20mm as the pipe wall isn’t proportionally as thick, hence 3/4” needs a converter to get up to 22mm. 28mm tends to come back closer to 1” and can fit but can sometimes be hit and miss.

 

[phatboy]

I think I've sussed it, with you guys suggestions and some thought.

I was being silly.... trying to connect a push fit cap connector. The internals of the connector foul the thicker inners of the cistern inlet. I'll get a toilet flexi that's standard, and all should be well. Rookie plumbing.....