I have a radiator with BSP parallel threads. I want to fit BSP-male to 15mm couplers and use a shaped piece of 15mm pipe to connect to the radiator valves rather than using standard tails. I've bought some straight couplers from Screwfix (item 67110). I expected these to some with rubber or fibre seals but they didn't. The bleed valve and plug came with the radiator and have rubber O-rings to seal them. I presume I need the same to seal the couplers.
Suggestions?
Suggestions?