in this video I'm going to take a look at PTFE tape or thread sealant tape I'm
going to take a look at where you would need it that where you shouldn't really
need it so the only time you would actually use this is on a tapered thread
which has no other means of sealing it I've got a couple of examples here that
is a radiator bleed valve and if you look at that you can actually see this
got a sealing ring on it an O ring and that actually seals it so there is no need
to put any thread sealant on one of those another place where people tend to
use PTFE tape when it's not needed is on compression fittings compression
fittings actually seal by compressing the olive and that is the olive part
there so that goes tight up against there and then the nut actually
compresses that olive against the fitting and that creates a watertight
seal so you should never need to put any PTFE tip on a compression fitting
however if you do find that it is leaking and you can't actually seal it
you can actually put a wrap or a couple of wraps of PTFE tape around the olive
and that should stop the joint from leaking one place where you will
definitely need PTFE tip is on a BSP thread like that that is a tapered
thread and that is half-inch bsp that is a radiator tail so on that end we have
the threaded tapered part which screws into the radiator
and on there we have the compression fitting which will connect to the
radiator valves if you were to screw that in there as tight as you could get it
with no PTFE tape on it will definitely leak so this is one instance where you
will need PTFE tape to apply it simply put it on the fitting like so if you hold
the fitting in your left hand and then go around it in a clockwise direction
like that you guaranteed to go around in the correct direction if you go the
wrong way you can actually unthread the tape as you are screwing it in that was a
matter all that much as long as you get a good seal
once you've gone round that a few times you can then break that off and then you
can screw that into the radiator then once that's nice and tight you can
guarantee that will not leak so all things like flexi tails or flexi tap
connectors they don't PTFE tape around the threads because they
have a rubber sealing washer it's the same for a lot of Union nuts etc if you
were installing a bib tap onto a back plate you would obviously need PTFE tape
around there because there's no way of sealing it there is no washer
that would simply screw in there once you have covered it with PTFE tape and
any fitting with a O ring on relies on the O ring to do the seal so you'd
simply screw that in there ensuring that you don't cross thread it like so then
you would just tighten that up obviously you don't need to go mad when you do
that you don't want to crush it to bits but you just need to ensure that it is
reasonably tight and that will give you a perfectly watertight seal I hope this
video has been helpful I hope it has helped you to identify some places where you would
need PTFE tip and some places where you don't need it of course if you do get a
leaking thread there's absolutely nothing wrong with putting some PTFE tape
around there, there is every chance that it may seal it in a future video I'm going to
show you exactly what happens if you don't use enough PTFE tape I've had
quite a lot of comments over the years saying that I use too much of this stuff
well I have to say that it's only 30 pence for a roll of that and if you do put
too much on it's not going to cause you a problem if you put too little on you
are gonna get a leak and I have to tell you that it's part of my job I actually
use PTFE tape on condensate lines and steam lines and it is absolutely
critical that they don't leak so in a future video I'm gonna do a bit of
testing we'll do some pressure testing on some PTFE joints some that have only
got a little bit of PTFE and some that have the correct amount I'd like to
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