Radiator lockshield valve - what type?

[ames]

Hi. I need to remove a radiator but just need to check - the lockshield valve seems to have an adjustable cover. It won't come off and has + and - signs on with arrows. If I turn it in the minus direction will that isolate the radiator? (Obviously also turning off the thermostat valve).

I removed them years ago but can't remember what worked and all the videos talk about taking the caps off. Cheers
View attachment 277799

 

[terryplumb]

Cant view the attachment ,post a pic directly onto this site.
To close the valve turn it clockwise.