Silicone thread sealant?

[AdamCH]

The fitting instructions for a radiator I'm buying says to use silicone thread sealant on all threaded components manufactured with ‘O-rings’.

I'm familiar with pfte tape but can anyone advise on silicone thread sealant?

 

[Homesafe]

PTFE normally used .
Unless you have a really fancy/gay rad

 

[Charnwood]

use silicone thread sealant on all threaded components manufactured with ‘O-rings’.

Not got much confidence in O rings, have they.

I'm presuming they mean rad valves. Most are taper thread. A few are available with parallel thread and O ring, but they rare.