Removing Middle Connection Radiator

[ronivek]

As above trying to remove a middle connection radiator; no idea what the official term for these is but this is what the connection looks like:

Am I right in thinking the nut on the top left is the lockshield valve? Or could it be this indented bit below:

Any pointers on how to safely remove this radiator would be greatly appreciated!

 

[CountryFan]

Twin entry radiator valve. Unsure of the lockshield I’m afraid, but looks more likely the top nut.