Replacing Danfoss lockshield valve

[Tom Gebbie]

Replacing a rusty radiator (installed 2000) the brass head of the Danfoss lockshield sheared off as it reached fully closed. I assumed that it was a 10mm with a 1/2" BSP connection to radiator. Offering up the nut (18.6mm across the flats) on the old 10mm insulated microbore it was found to have a slightly different thread from the new lockshield. Is the only solution removing the olive and nut from microbore (beyond my capability I guess) or is there a modern lockshield that would fit the old nut?

 

[oz-plumber]

Unfortunately, you have come across one of the biggest PITA situations plumbers come across.
Non matching threads on radiator valve connections.

Either find an exact replacement of the valve or replace the nut and olive with the new valve.

One can be done with out draining the system and the other requires draining the system