An old (30+ years) radiator valve is leaking slowly. I seem to remember from somewhere that you can remove the spindle to replace the O-rings without shutting down or draining the system. Is this the case? (Presumably the valve is held closed by water pressure - possible??)
Sometimes just tightening the top nut on the spindle will stop it (although sometimes you need to do it so much the tap won't turn then). In which case you need to repack the spindle gland.
Sort of ;-)
If you close the valve, then that should prevent the water from reaching the spindle. Depending on the valve design, you may also need to drain the rad itself though.
To repack the spindle gland you can either go the traditional route with some hemp and a bit of grease, or you can use PTFE tape. With the latter, wind a few turns on the spindle itself (with the tape bunched rather than flat), then push it down into the gland, wind a few more turns and repeat until its nicely stuffed, then stick the nut back on and tighten.
IIRC there is a video somewhere of this... ah, try this:
well for me is to pack it full of Boss Green (I've had a single pot seemingly for ever, and it will probably outlast me) under the nut. I've had to do it to several valves in my house, and none has yet leaked since. I expect that Plumber's Mait (did I mis-spell it correctly?) would work, too.
Yes, I do sort of avoid adjusting them (and I don't often get the urge to, anyway), since I can imagine it being more likely to get pushed out past the stem. But I'd just fill it up again :)
I can't understand why he is keeping some tails of the PTFE and getting it into the thread. If I do this I always wind it round and stuff it all down in the housing before fitting the packing nut.
If its a consolation, after writing that I though I really ought to actually go and do that on my garden tap since that leaks from the gland.
Only took five mins and worked a treat ;-)
Just wound a dozen or so turns run the spindle under the gland nut, and then a couple of turns on the nut thread itself for good measure. Use the nut to push the PTFE into the gap, and did it up a few turns.
I used the !"pach it with PTFE tape" technique which worked fine. I have a question about that though. Is the leak really at the point where the packing acts? I thought the purpose of the O-ring there was to prevent the spindle being able to rise under pressure. It also determined how stiff the tap was to turn. The actual leak is further down the spindle. (I don't have a lot of idea what I am talking about!!)
The spindle won't rise under pressure. The lower part (the part inside the valve, which you can't see) is threaded, and moves the working part of the valve nearer to or further from the seat as the spindle is rotated. Because there is water inside the valve, but the spindle has to emerge into fresh air to enable a hand-wheel to be attached to it, there needs to be some sort of seal round the spindle to prevent water from leaking out. On newer valves, this is provided by an 'O' ring. On older valves, like yours, the seal is in the form of a gland - compressible material round the shaft, which is compressed by doing up the gland nut so as to fit tightly round the shaft. Over time, this wears to the extent that fully tightening the nut is insufficient to re-make the seal. This is when you have to resort to adding additional packing - be it hemp, string, or PTFE tape.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.