Brass "Faringdon" lockshield valves leaking

[Pearly King]

I have just tried to balance my heating system (16 cast iron rads, 3 towel rails), all the lockshields were fully open. When I try to close them down, they all leak, from a dribble to a gush. When I say all, I tried 6 and then stopped. The system was installed 9 years ago. Despite extensive googling, I cannot find anything to say if/ how they can be repaired. The lockshield is not the traditional type, it has an inset screw that is adjusted with an allen key. I am assumming that there is some type of rubber olive that has perished. Can anyone advise if/how I might be able to fix this. The installer has long since retired, so I cannot speak with them.
To aid identification, the attached photos show: the TRV, lockshield, lockshield with cover/cap removed.

 

[Chuck]

I think that type of valve is made / imported by West Radiators:

WestRadiators.co.uk

westradiators.co.uk

the data sheet shows how they are assembled:

https://advice.traderadiators.com/downloads/Eton-Angled-Manual.pdf

Try contacting West and see if they know about this problem and can supply replacement seals or cartridges. If you've got six valves all failing in the same way at the same time it seems likely that it was a manufacturing fault. Perhaps the o-ring material was incorrect or the seatings were ground too deep.

 

[exedon2]

Also supplied by Supplies4heat
And at eye watering prices by The radiator company .
I would suspect Italian imports as that's where 2 above company's source there rads.

 

[Pearly King]

Also supplied by Supplies4heat
And at eye watering prices by The radiator company .
I would suspect Italian imports as that's where 2 above company's source there rads.

Thanks.

 

[Pearly King]

I think that type of valve is made by West...................

Many thanks. I will follow up with West.