On 13/03/2021 18:39, Murmansk wrote:
This is the tap

https://user.fm/files/v2-1a9c9dcfb60...750.SMALL.jpeg

Diameter of metal bit is about 28mm

All the ones I have seen are smaller and the ones that clamp on need the tap's neck to be at right angles to the outlet

Make the extra bit of effort and add an outside tap. It's amazing how
useful having one can be.