Time to replace radiator valves?

[Greenman]

Some of my radiator valves are slowly leaking - the other side to the thermostats.

I have tried PTFE along the threads and retightening - still leaking.
I have tried Plumbers Mate around the threads and retightening - some are still leaking.

Is the tap and L-pipe connection all one unit and the washers have maybe worn out - time to replace?

 

[Madrab]

This whole unit is the lockshield,



Where are they leaking from, where the nuts connect to the pipe or from the top of the brass valve at the spindle?

 

[Greenman]

Thank you for your reply.
The water is weeping from the top of the brass valve at the top of the spindle.

I gather there is a waher at the bottom of the spindle, which has worn out and spindles cannot be replaced as they are part of a sealed unit?

 

[Madrab]

I gather there is a waher at the bottom of the spindle

Depends, some have what's called a gland which is a bevelled nut that screws down onto a packing medium around the spindle and that then forms the seal. Others have O-rings.

The ones with glands can usually be nipped up and stops the weeping, the o-ringed versions can't be as it's the o-rings that are worn, both are getting past it though if letting by and ultimately will need replaced.

 

[Greenman]

Thank you for your reply.

It looks like I have a replace old for new project coming up; preferably in late spring when the system can be drained down as not being used then.