Lockshield is 1/2 inch X 1/2 inch but only 15mm available

[vice]

Hi I've noticed that my lockshield valve va has been leaking. The construction doesn't seem to have a bonnet that I could tighten up and the only replacement I can find are half inch by 15 mm. Presumably I can replace the 1/2 inch on the pipe with 15 mil but then I'll be putting an olive in the same place.
Any tips or ideas?

 

[Terrywookfit]

Most valves will be a straight swap.

 

[vice]

Without changing the compression nut on the pipe?

 

[kidgreen61]

You may have to change both nuts, just cut the olive off and replace.
The 1/2" refers to the 1/2" BSP thread on the end that takes the rad tail, there is very little difference in size between 1/2" and 15mm pipe.

 

[fixitflav]

Without changing the compression nut on the pipe?

Almost certainly no need. The thread on 15mm compression fittings is nowadays always 1/2" BSP AFAIK. I have some old ones in my scrap pile which have finer thread, but I haven't seen any recently.
Incidentally 22mm compression fittings are not threaded 3/4" BSP as there isn't enough wall thickness.

 

[ianmcd]

just cut the olive off and change the complete valve, will look crap if you use the existing nut