I have removed a radiator in a room that's changing use (and there
will be other things attached to the wall where the radiator was).

I'm happy enough that the lock-shield valve will be watertight and
tamper proof but I'm not at all convinced about the thermostatic valve
at the other end - in fact I've knocked it a couple of times and
provoked a squirt of water.

Is there anything designed to cap the end or, alternatively, what's the
best way to bodge it? It had a fairly large diameter union onto a
short stub which in turn was screwed into the radiator. Even if I
knew what size the nut is I'm not sure what one would need to make a
watertight cap.

--
Chris Green