We are servicing Mums old CH system. It was a coal fired single pipe /
gravity jobby but was modified a few years back (30?) to be a fully
pumped system. with a wall mounted low capacity b/f boiler.
Today I tapped a 15mm draincock into one of the 1-1/4" brass elbows
 and whilst the system was drained down and because most of the
rad-valves were either showing signs of leaking or nearly impossible
to turn (impossible for Mum to turn) we went round them today,
removing, stripping, cleaning and re-fitting.
The only thing I'm not quite sure about is what to re-pack the glands
The seem to be filled with a string of some sort and most came out
Some of them are gate-valve design (as linked above and tend to be
fitted at the tops of the rads) and the others are more like a
stopcock but with a free rotating metal 'cone' instead of a rubber
So, what to do about the gland packing. I've tried running the old
stuff though some Boss White and it softens up a bit and I can
carefully feed it back in (but can't get it all back in) and once the
gland nut is nipped up it all feels much smoother and like it wouldn't
leak, but is there a 'proper' solution please (and no, Mum doesn't
want to replace the lot). ;-)
I used 'Plumbers Grease' on the actual screw threads (that's what they
gave me in the merchants).
Cheers, T i m
 Whoever upgraded the boiler removed the ability to drain the
system lower than the boiler return. ;-(
I do a variation of that and simply wind 15 turns or so around the
spindle with the tape roll held in such a way as the tape ends up
bunched rather than laying flat. Then snap it off, and force it down
into the gap with the gland nut. Nip it up a little bit so the tap still
turns freely, and that should do it. (you may need to experiment with
the right amount of tape for your glands - it will also vary depending
on if you rake out the old packing or just leave it and add some more on
Ah, sorry about that. I do normally have a quick look but I assumed
people wouldn't do this sort of thing any more. I forgot this was
Yup, I got that <g> (and have stripped and re-done 4 of 7 valves so
far) but as the local (old skool) plumbers merchant couldn't supply a
'new' replacement packing materiel (and he suggested I re-used the old
as it was in good nick considering), that's what I started to do.
However, preferring to do things 'right' if possible, I thought I'd
Hmmm, I'm not sure I'd want him fixing my stuff. Ok if there was an
actual leak I guess or until you drained the system fully.
After reading all the replies here I did a more specific Google and
found quite a few people liking the 'Loctite 55'. This seems to be a
PTFE 'cord' that is probably not far off what some PTFE tape might end
up as once pushed inside the gland by the nut.
General thoughts though .....
These taps valves have been in use, potentially un-serviced for over
60 years and were obviously of good quality when they were made. Even
to the point where the gland packing collar is separate from the
tightening nut and you can adjust the nut over the top of the ferrule
that covers most of the hardware when in place (and you don't even
have to take the Bakelite knob off to do it). ;-)
Whatever was used for the packing hasn't marked any of the spindles
*at all* in 60 years.
Whatever was once the 'lube' in the 'string' (?) has just dried out
and therefore the 'string' hardened and therefore making the spindle
prone to leaking, or, if when tightened to prevent the leaking, made
the spindle much harder to turn due to there being no 'give' in the
So, ideally and especially if it didn't cost a lot (in time getting
the right stuff or money) to replace what was there with some of the
same, that would be ideal.
Now, in the real world Mum is 82 and we have loads of more important
things to do (for here and ourselves), so as long as she can turn
these things on and of (she's not 'frail as such' atm) and they don't
leak then I'm guessing that will 'do' (even though it goes against my
grain to some degree). (Possibly) 'Spoiling the ship for a hapenth of
tar' as my Dad used to say. Doing it right won't take any longer than
doing it nearly right, once you have the right materials. ;-)
So, in case I can easily find some suitable 'string', any idea what
lubricant I should use on it? ie, Is Boss White going to stay flexible
long enough? Silicone grease ... Plumbers Grease (or as I believe I
saw mentioned somewhere, a waterproof grease (I have some suitable
white grease for marine propeller shaft bearings that I got when I
savaged an irreparable washing machine (sealed plastic tub) 5 years
It's one of these things where it seems to be good gear in a great
condition and part of the reason for that condition is that it was
designed to be right (and last) in the first place.
So, what about a decent quality parcel string? I'm pretty sure the
sort of 'hot' that a radiator gets isn't hot enough to bother any type
of old skool / cotton(?) string?
Cheers and thanks again for all the replies and heads up guys. I could
end up using any of them. ;-)
Cheers, T i m
That particular vid was a tad kack handed, however he does do some
interesting things - with a rather "warts and all" production method.
There should be no need to drain for work on a top gland if the tap
itself still shuts off ok. They normally only leak when the tap is "on".
Yup, cord is probably easier for this task, but ordinary tape works as
well... (I normally go for tape since I have copious reels of it and no
cord - which makes the decision making process easy ;-)
and if it lasts another 60 years that will save doing it again in a
Boss white tends to hardern IME... So a grease would be better. Not sure
it matters much what sort in this application since there are no rubbers
or plastics to degrade, and you won't be drinking from it.
A string twisted out of some traditional hemp would probably work well.
Possibly not - yours look like more of a gate valve design than a more
traditional tap arrangement. Only way to be sure is to try and see.
(gate valves have a bit of a habit of allowing seepage at the best of
times, although for this application that does not really matter unless
you want to remove a rad for decorating).
a n other natural fibre - similar to hemp and flax etc.
Like I said elsewhere, 50% of them are gate valve design (these are
fitted at the top of a rad) and the others are a 'cone' pressing into
a seat, more like a conventional tap / rubber (but without the full
'seal' as such). These are only fitted to the bottoms of the rads.
Ah, again not that straightforward as there is only one valve per rad.
Ah ok, and no better / worse properties for this role than help then?
Sorry must have missed that bit - I was assuming one of each per rad.
A rad valve (in the lockshield role) is a pretty undemanding
application. It rarely gets "used", and just has to contend with some
thermal cycling between predictable limits. Spose you could swap em for
TRVs, but then you would be stuck with plumber style rad balancing (i.e.
let the TRV sort it out!)
I'm thinking the whole valve assembly is much bigger than today's
systems? For a start it's sitting on 3/4" rather than 15mm pipe?
Well, that is always my plan. I'm in the process of making good all
the issues created by someone who was probably 'doing his best' but
where nearly *everything* he did carries with it the consequences of
someone who isn't interested or practically skilled in anything (as it
Maybe I have learned the hard way .. 'Too much haste, not enough
speed' ... ;-(
I have also learned that some people can't picture things (not here),
even when it is spelled out and agreed.
Me: (from previous experience) "Ok, so you are happy to do X <that
way> and so I'll leave you to it.
<next day, looking at some completely different and ruined solution>
"So, do you remember that chat we had yesterday about what we agreed
would be the best way to proceed ... why do you appear to have done
something completely different?"
Cheers, T i m
You can get 22mm TRVs although they are far harder to find.
Myson certainly used to do one:
However, given the amount of space you have, you could probably include
a reduction fitting in there without any difficulty.
On Fri, 28 Sep 2012 19:57:36 +0100, Ian Jackson
Mum had a tin of 'Garden twine' but it was brown and looked the same
as a roll of stuff I bought earlier from Homebase as 'Jute' heavy duty
Yeah, I'm stripping the whole valve down to clean a lube in any case.
I've tried 'Plumbers grease' and a heavy white waterproof grease so
Some Googling suggested 'wool' and 'petroleum jelly' as well. ;-)
Cheers, T i m
A pretty patterned green tin? My wife bought me one for a Christmas
present! It's fine for tying up plants etc, but it's hardly heavy duty
parcel string. I think it only has three strands.
It's actually a bit too thick for radiator valves, so simply separate
the strands, and use one of them. [You can do two more valves with the
other two strands!]
What about KY Jelly? Probably not, as I think it's water-soluble.
You are probably right. The roll I bought from Homebase was the
strongest of three options. The first two was white and the last this
brown Jute stuff. However, I was looking more for the tightness of
construction rather than its parcel tying strength as such. ;-)
Ah, maybe these rad valves are bigger (as it's all mostly a 1-1/2" ex
gravity system) so even the largest stuff goes in easily. And it's
things like that that get me wondering when folk suggest stuff that
*might* be more appropriate for the sorts of sizes you encounter
today. These fittings are pretty big. When I do the next one I'll take
the picture next to a rule. ;-)
I generally can't do it any other way I'm afraid Ian. ;-(
The valve on the towel rail is of the gate valve type and they seem to
have a bigger / external type flange and even with my 18" adjustable,
are nearly impossible to move (I've done one so far). You might be
able to see it here.
Imagine where the chrome cover screws over the top, that lip you see
at the joint between the cover and the body is the diameter of the
flange. (the pip going to the rad is 3/2" and the pipe going up the
wall is 1-1/4").
The bottom valves (on the cast iron rads) are internal to the tap body
(and they share the thread with the chrome nut cover etc). I've taken
the hot air gun round Mums and will try a bit of heat in the hope that
might get it moving a bit. The one on the towel rail is exceptionally
'graunchy' and probably could do with both threads lubing (the gate
itself screws into the spindle on a square cut thread, as the spindle
screws into the body on a square cut thread. Some of these have come
out with the signs of some lube but this one feels very dry).
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