I'm swapping a radiator and intend to fit one wider than the current. the pipes are 10mm and come down the inside of the wall. my plans is to cut into the wall and find a nice clean bit of pipe then either use HEP20 or copper to the radiator The issue I have is the lock shield is currently also a drain valve and I'd like to retain this but its very tight as the wall is not very wide. Is there a 90degree radiator tail or an elbow with male thread one one end and female on the other? For instance the attached?