I have some new 22mm bath taps I need to get onto my existing 15mm copper pipe but my 22mm nuts are too large for the taps. What's the nut on the end of a flexi called? Can I get them as part of a reducer/isolator? The taps themselves are described as "Pipe Size: 22 mm (3/4" BSP)" and the nut from the reducer coupling I used is 22mm but doesn't make mention of BSP anywhere.

