Immersion heater thread sealing?
 

Hi,

Just before I start - what's the current wisdom on sealing immersion heater
threads?

a) PTFE
b) Gas PTFE
c) Something funky from http://www.bes.co.uk/products/213.asp

Obviously I'll avoid the traditional hemp and Boss White as I'd like to be
able to undo them one day without turning the cylinder into a pice of
modern art(!)

Also, which is reckoned to be the best bet for smaller taper threads, like
3/4" sensor pocket doobries?

All the rest of the connections are direct to 22mm compression which is
nice - less fiddling.

Cheers

Tim

Immersion heater thread sealing?
 

In article ,
Tim S wrote:
Just before I start - what's the current wisdom on sealing immersion
heater threads?

a) PTFE
b) Gas PTFE
c) Something funky from http://www.bes.co.uk/products/213.asp

Never had any problems with PTFE.

Obviously I'll avoid the traditional hemp and Boss White as I'd like to
be able to undo them one day without turning the cylinder into a pice of
modern art(!)

Also, which is reckoned to be the best bet for smaller taper threads,
like 3/4" sensor pocket doobries?

Likewise.

All the rest of the connections are direct to 22mm compression which is
nice - less fiddling.

Only other thing I use for 'difficult' connections is Fernox LS-X which is
a form of silicone. I had problems getting a seal between a copper tap
connector and the plastic pipe to the toilet cistern. That sorted it.

--
*Caution: I drive like you do.

Dave Plowman London SW
To e-mail, change noise into sound.

Immersion heater thread sealing?
 

"Tim S" wrote in message
.. .
Hi,

Just before I start - what's the current wisdom on sealing immersion
heater
threads?

a) PTFE
b) Gas PTFE
c) Something funky from http://www.bes.co.uk/products/213.asp

Obviously I'll avoid the traditional hemp and Boss White as I'd like to be
able to undo them one day without turning the cylinder into a pice of
modern art(!)

Also, which is reckoned to be the best bet for smaller taper threads, like
3/4" sensor pocket doobries?

All the rest of the connections are direct to 22mm compression which is
nice - less fiddling.

Cheers

Tim

I just use ordinary clear silicone on everything. You do have to let it go
off completely before turning the water on though. If it hasn't set then the
water just forces a path through and it might as well not be on there at
all.
--
Dave Baker

Immersion heater thread sealing?
 

On Fri, 17 Jul 2009 08:09:55 +0100, Tim S wrote:

Hi,

Just before I start - what's the current wisdom on sealing immersion heater
threads?

I wrap PTFE around the thread (to help with removal next time), bunching a
load of the tape up against the fibre washer at the shoulder of the thread
to assist the fibre washer in sealing to the cylinder boss.



--
John Stumbles -- http://yaph.co.uk

The astronomer married a star

Immersion heater thread sealing?
 

On 17 July, 08:09, Tim S wrote:
Hi,

Just before I start - what's the current wisdom on sealing immersion heater
threads?

a) PTFE
b) Gas PTFE
c) Something funky fromhttp://www.bes.co.uk/products/213.asp

Did one recently. Then did it again yesterday when I changed the
cylinder. It didn't leak with either the old cylinder or the new one.

You get a washer with the immersion heater, which should form a seal
between the two flat, clean flange faces.

I put PTFE tape around the threads to be sure. I used the virgin white
PTFE gunk, on the BES link you posted, on both flange faces and the
PTFE tape to be sure, to be sure. It worked for me.

Immersion heater thread sealing?
 

" wrote in message
...
On 17 July, 08:09, Tim S wrote:
Hi,

Just before I start - what's the current wisdom on sealing immersion
heater
threads?

a) PTFE
b) Gas PTFE
c) Something funky fromhttp://www.bes.co.uk/products/213.asp

Did one recently. Then did it again yesterday when I changed the
cylinder. It didn't leak with either the old cylinder or the new one.

You get a washer with the immersion heater, which should form a seal
between the two flat, clean flange faces.

I put PTFE tape around the threads to be sure. I used the virgin white
PTFE gunk, on the BES link you posted, on both flange faces and the
PTFE tape to be sure, to be sure. It worked for me.

I think the face should provide the seal - not the thread. Is the washer
damaged?. If so - then a twisted cord of PTFE at the shoulder of the thread
may work. Best to get a new washer though - and a smear of grease on the
thread to ease it out in the future.

Immersion heater thread sealing?
 

In article
,
wrote:
You get a washer with the immersion heater, which should form a seal
between the two flat, clean flange faces.

I put PTFE tape around the threads to be sure. I used the virgin white
PTFE gunk, on the BES link you posted, on both flange faces and the
PTFE tape to be sure, to be sure. It worked for me.

One benefit of PTFE is it may prevent corrosion between the threads making
removal easier when the new immersion fails - as it surely will. ;-)

--
*It is easier to get older than it is to get wiser.

Dave Plowman London SW
To e-mail, change noise into sound.

Immersion heater thread sealing?
 

"Dave Plowman (News)" wrote in message
...
In article
,
wrote:
You get a washer with the immersion heater, which should form a seal
between the two flat, clean flange faces.

I put PTFE tape around the threads to be sure. I used the virgin white
PTFE gunk, on the BES link you posted, on both flange faces and the
PTFE tape to be sure, to be sure. It worked for me.

One benefit of PTFE is it may prevent corrosion between the threads making
removal easier when the new immersion fails - as it surely will. ;-)

--
*It is easier to get older than it is to get wiser.

Dave Plowman London SW
To e-mail, change noise into sound.

If more people thought about the future removal then there would be less
posts about how to remove things that are stuck!

I believe the purpose of the thread is mainly to provide a clamping force
onto the sealing washers. Trying to seal the thread is not the best way to
go. Only tapered pipe threads are supposed to be for the purpose of sealing
as they tighten up to form an interference fit.

Threads have "truncated" form which inevitably leads to there being a
clearance - hence leakage route around the root of the thread.

Please - think of future removal. Good clean seating faces - without
damage - a new washer - and the lightest application as Dave suggests should
do the trick.

Immersion heater thread sealing?
 

On 18 July, 11:29, "John" wrote:
"Dave Plowman (News)" wrote in ...





In article
,
* wrote:
You get a washer with the immersion heater, which should form a seal
between the two flat, clean *flange faces.

I put PTFE tape around the threads to be sure. I used the virgin white
PTFE gunk, on the BES link you posted, on both flange faces and the
PTFE tape to be sure, to be sure. It worked for me.

One benefit of PTFE is it may prevent corrosion between the threads making
removal easier when the new immersion fails - as it surely will. ;-)

--
*It is easier to get older than it is to get wiser.

* *Dave Plowman * * * * * * * * London SW
* * * * * * * * *To e-mail, change noise into sound.

If more people thought about the future removal then there would be less
posts about how to remove things that are stuck!

I believe the purpose of the thread is mainly to provide a clamping force
onto the sealing washers. Trying to seal the thread is not the best way to
go. Only tapered pipe threads are supposed to be for the purpose of sealing
as they tighten up to form an interference fit.

Threads have "truncated" form which inevitably leads to there being a
clearance - hence leakage route around the root of the thread.

Please - think of future removal. Good clean seating faces - without
damage - a new washer - and the lightest application as Dave suggests should
do the trick.- Hide quoted text -

- Show quoted text -

PTFE is a lubricant, it's used as non-stick coatings. It's use makes
the threads easier to assemble and disassemble, the main reason for
using it in this instance.
I had put the original immersion heater in 5 or 6 years ago, probably
with the same method, but I do not now remember.
It came out with no grief and no distortion of the cylinder boss.

Immersion heater thread sealing?
 

Tim S wibbled:

Hi,

Just before I start - what's the current wisdom on sealing immersion
heater threads?

a) PTFE
b) Gas PTFE
c) Something funky from http://www.bes.co.uk/products/213.asp

Obviously I'll avoid the traditional hemp and Boss White as I'd like to be
able to undo them one day without turning the cylinder into a pice of
modern art(!)

Also, which is reckoned to be the best bet for smaller taper threads, like
3/4" sensor pocket doobries?

All the rest of the connections are direct to 22mm compression which is
nice - less fiddling.

Cheers

Tim

Thanks to everyone. Yes, there is a fiber washer, now that I've opened the
box to look - never fitted an immersion before(!)

So PTFE tape around the thread and maybe just a smear of Virgin White on the
flange faces which sounds harmless as it's non setting.

Ta

Tim

Immersion heater thread sealing?
 

"Tim S" wrote in message
.. .
Tim S wibbled:

Hi,

Just before I start - what's the current wisdom on sealing immersion
heater threads?

a) PTFE
b) Gas PTFE
c) Something funky from http://www.bes.co.uk/products/213.asp

Obviously I'll avoid the traditional hemp and Boss White as I'd like to
be
able to undo them one day without turning the cylinder into a pice of
modern art(!)

Also, which is reckoned to be the best bet for smaller taper threads,
like
3/4" sensor pocket doobries?

All the rest of the connections are direct to 22mm compression which is
nice - less fiddling.

Cheers

Tim

Thanks to everyone. Yes, there is a fiber washer, now that I've opened the
box to look - never fitted an immersion before(!)

So PTFE tape around the thread and maybe just a smear of Virgin White on
the
flange faces which sounds harmless as it's non setting.

Ta

Tim

Sounds good to me. Good luck. (and for the future when you remove it - you
should be okay.)

Immersion heater thread sealing?
 

"Tim S" wrote in message
.. .
Tim S wibbled:

Hi,

Just before I start - what's the current wisdom on sealing immersion
heater threads?

a) PTFE
b) Gas PTFE
c) Something funky from http://www.bes.co.uk/products/213.asp

Obviously I'll avoid the traditional hemp and Boss White as I'd like to
be
able to undo them one day without turning the cylinder into a pice of
modern art(!)

Also, which is reckoned to be the best bet for smaller taper threads,
like
3/4" sensor pocket doobries?

All the rest of the connections are direct to 22mm compression which is
nice - less fiddling.

Cheers

Tim

Thanks to everyone. Yes, there is a fiber washer, now that I've opened the
box to look - never fitted an immersion before(!)

So PTFE tape around the thread and maybe just a smear of Virgin White on
the
flange faces which sounds harmless as it's non setting.

Sealing the thread should really not be a factor. It's sealing the flange to
washer interface that matters. The thread is not even designed to seal as
it's a straight not taper thread. You wouldn't try to seal the threads when
bolting a cylinder head to an engine block when it's only the gasket seal
that matters. Put a light smear of silicone on both sides of the washer, do
it up tight and leave it for a few hours for the silicone to set before
turning the water back on. Bob should be your aunty's husband.
--
Dave Baker

Immersion heater thread sealing?
 

Dave Baker coughed up some electrons that declared:


"Tim S" wrote in message

Thanks to everyone. Yes, there is a fiber washer, now that I've opened
the box to look - never fitted an immersion before(!)

So PTFE tape around the thread and maybe just a smear of Virgin White on
the
flange faces which sounds harmless as it's non setting.

Sealing the thread should really not be a factor. It's sealing the flange
to washer interface that matters. The thread is not even designed to seal
as it's a straight not taper thread. You wouldn't try to seal the threads
when bolting a cylinder head to an engine block when it's only the gasket
seal that matters. Put a light smear of silicone on both sides of the
washer, do it up tight and leave it for a few hours for the silicone to
set before turning the water back on. Bob should be your aunty's husband.

Regarding the thread - yes I gathered that. I think the PTFE was suggested
in order to stop the metal threads jamming up over time, which seems
reasonable. Couple of turns of PTFE would be enough to handle that problem.

Silicone: wouldn't that make it hard to undo?

Cheers

Tim

Immersion heater thread sealing?
 

"Tim S" wrote in message
.. .
Dave Baker coughed up some electrons that declared:


"Tim S" wrote in message

Thanks to everyone. Yes, there is a fiber washer, now that I've opened
the box to look - never fitted an immersion before(!)

So PTFE tape around the thread and maybe just a smear of Virgin White on
the
flange faces which sounds harmless as it's non setting.

Sealing the thread should really not be a factor. It's sealing the flange
to washer interface that matters. The thread is not even designed to seal
as it's a straight not taper thread. You wouldn't try to seal the threads
when bolting a cylinder head to an engine block when it's only the gasket
seal that matters. Put a light smear of silicone on both sides of the
washer, do it up tight and leave it for a few hours for the silicone to
set before turning the water back on. Bob should be your aunty's husband.

Regarding the thread - yes I gathered that. I think the PTFE was suggested
in order to stop the metal threads jamming up over time, which seems
reasonable. Couple of turns of PTFE would be enough to handle that
problem.

Silicone: wouldn't that make it hard to undo?

Shouldn't do no. I do mean a very light smear though. Just enough rubbed
into the surface of the gasket to fill any imperfections. Last time I fitted
an immersion without anything on the gasket it leaked like a sieve no matter
how tight I did it up. We're not really talking precision machined flanges
here and frankly the gaskets are crap. A smear of silicone sorted it though.
--
Dave Baker