Fitting Drain-off Radiator Tails

[john51]

I am replacing all my radiators and valves and thought it would be useful to fit drain-off tails. I'm confident about fitting normal rad tails with PTFE/compound, but the drain-off type need to end up in a position where you can get at the drain key head and fit a hose - ideally with the hose fitting pointing down. Sometimes this means backing off the fitting from the fully tight position.

What is the recommended way of doing this? Even when you add more wraps of PTFE it doesn't take much effort to turn it past the ideal position. How can you judge when the seal will be pressure tight?

thanks

John

[Cicero]

================================= I think you're a bit confused about how these valves made. They're normally in two parts. One part (with large loose ring nut) is screwed into the radiator using whatever sealant you choose (usually PTFE tape). When this part is secure the other part - the main body of the valve - is attached by fitting its tapered end into the part fitted into the radiator. This part can be fitted in any orientation you want because it's secured by tightening the ring nut - not by screwing in.

Have a look here for the general idea:

[john51]

Thanks Cic. I appreciate what you are saying, but I wasn't referring to the type of drain-off valve you referenced, but the drain-off tail that lets you drain a rad for removal after closing off the TRV/lockshield valves. In this case - see for example

?intPage=1332|intLang=2|strLang=en|intLevel=1|intLevel2ID=1332- the drain-off part is on the radiator tail itself and screws directly into the rad on a tapered thread like an ordinary tail.

John