Odd lockshield valves - can anyone help me adjust them?

[gomez]

Hi - got some rather old rads in my place with some odd valves. Can anyone tell me how I might adjust these? It doesn't appear to be obvious! I am not a plumber but grateful if any of you could help me.

Can get pics of better quality if necessary. Basically first pic shown valve normally and 2nd shows it with the face bit screwed off.

Regards

Gomez

 

[tamz]

It is an old conex lockshield.
Put the cap back on it and turn the screw.

 

[gomez]

Great. It does say Conex on the cap. So I just use a flathead to turn the screw thing in and out and dont need to even take the thing apart? It seems a bit weird. The screw doesn't appear to be adjusting anything. I presume the further the screw is turned in the more closed the valve?

 

[tamz]

If you keep screwing it in it will stop and the valve will be closed. Works on something the same principle as a tap.