How do I get top off an old Danfoss thermostatic valve?

[Trooperh]

I want to check whether the pin is stuck on old Danfoss thermostatic valve ( no model number on it just Danfoss Thermostatic) . There is a lug on the black knurled ring at the bottom of the valve housing with a very small Allen screw which I have loosened off and tried unscrewing top but nothing moves. Am I missing a trick here?
On top of the valve there is a central black portion which is also knurled so I am assuming this might have something to do with removing head.
Can anyone help?
I tried uploading a picture of valce concerned with no success, how would I do this?

 

[Gas2Air]

Take the allen screw out completely. Wiggle it like mad and pull it off. They can be tight sometimes.

 

[dang32]

or even simpler you turn the knurled nut which is sprung loaded and it pops off

 

[Dan Robinson]

how would I do this?

Just drag the picture file into the message box.

Or click the "upload a file button".

 

[Trooperh]

Hopefully here is a picture of the valve concerned. Does this make any difference to the adv

ice already given?

 

[dang32]

sorry my advice was wrong. I was thinking of a different valve. the first post was correct

 

[Trooperh]

Got the top off with a good wiggle after removing Allen screw and sure enough pin was stuck down. With a little bit of judiciuous tapping up it came and rad is now warm and toastie.
Thanks for all advice given.