Tap connector sizes explained

[mike004]

Could someone clarify for me the terminology used for plumbing pipe sizes? It seems to be a mixture of imperial and metric!

I want to buy a flexible tap connector for my bath that connects a 15mm copper pipe to a bath tap tail.
I haven't bought the new taps yet, but I have the impression that all bath taps use a 22mm size tail. And all basin taps have a 15mm tail.

So, what connector size should I go for?

Thanks
Mike

 

[ChrisR]

Bath taps generally have a 3/4" threaded tail, and sink/basin taps 1/2".

They usually need fittings to connect to 22mm and 15mm pipes, respectively, though some bath supplies are 15mm too.

 

[IJWS15]

the tap connectors are what is nown as BSP (British standard pipe) and the size relates to a nominal bore (inside diameter) normally of brass or steel tube (e.g gas pipe) so a 1/2 BSP thread has a bigger diameter than 1/2"

The compression connector at the other end relates to the outside diameter of the copper or plastic tube you will be connecting to.

For a bath I would expect 22mm to 3/4 BSP although the cold may need a 15mm to 3/4BSP