what size rad valve is this thing???

[warbulator]

so we have a 70s open baxi heating system and the upstairs rad out valve ( cheapo chrome looking thing) started to leak through the spindle and its loose ratling and no tightening of the gland helped, its goosed.
the bottom pipe is 8mm but the very thin thread on the valve to the rad is a big thread like maybe an inch?? what do i need to ask for at plumb centre. have sealed off thet rad/valve for now and was plannin gto freeze the 8mmpipe to change the valve. do i really have to put the new valve insert into the rad or can i just use the new valve to the existing rad thread/nut?

 

[buck51]

It all depends on what you have now, and what you get to replace it,
A photo saves a thousand words !!!

 

[warbulator]

ok have got a measurement. the thread on the top of the valve appears to be 1" and the huge nut is 1 2/16" or 29mm