Radiator valve ID

Some of our radiators seem to be missing part of the valves:
http://www.chiark.greenend.org.uk/~theom/ephemeral/radiator.jpg
(the pin goes in if you press it)
Am I right in thinking this is the base of a TRV which somebody has half inched?
There doesn't appear to be any screw thread on it, just the lug sticking out the front. Is this something that any TRV should fit, or is it a special kind of valve where I need to look for matching TRVs? If so, what is it called?
Thanks Theo
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Early Danfoss trv's had a clamp around the part of the head which slipped over the boss which the pin sticks out of. Have a look through their range of replacement heads as a starting point.
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On 18/05/2020 22:17, Cynic wrote:

I thought DANFOSS because my Drayton Wiser valves came with collar that might fit, but on checking I think its different.
DANFOS seem to have had a number of different heads over the years, a couple of which look like yours. The Drayton Wiser guide has dimensions for all so you should be able to figure out which is which
https://wiser.draytoncontrols.co.uk/sites/default/files/documents/4369_adapter_guide_2pg_v4_web.pdf
that looks like an RAVL
https://www.heatingcontrolsonline.co.uk/danfoss-randall-ravl-2950-sensor-p-185.html
but I can't be sure.
Personally I would change them. If they havn't moved in a long time they can stick and/or leak...
Dave
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I think they're fine - pins go up and down ok - just someone took the heads with them. Plumbing is something I Don't Do except in extreme circumstances, and getting a plumber in is a bit tricky at the moment.
I came across this: https://www.hivehome.com/radiator-valve-guide/installation which suggests they might be 'Giacomini' valves - does that tally?
(I happen to be considering Hive TRVs anyway)
Theo
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On 19/05/2020 11:46, Theo wrote:

I would have thought Heating was something you Don't Do at the moment too...
Andy
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But, last week we had overnight frost
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
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The nice people at Hive are sending me some adapters to fit their TRVs - which I haven't actually bought yet. That should be a good test...
(and once converted to M30 should take other TRVs too)
Theo
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