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Immersion heater meachanical flange - how to remove / tighten with no access to rear?

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The Other Mike

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Apr 12, 2010, 12:58:47 PM4/12/10
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I've got an immersion heater mechanical flange similar to that
supplied by Toolstation.

<http://www.toolstation.com/shop/Heating/Central+Heating/Mechanical+Flange+2+14/d230/sd2708/p38614?>

The flange is slightly loose, the cork seal leaking, and I have next
to no access to the rear, certainly not enough to get a spanner in. I
am sure the flange was fitted before the tank was welded together and
while there is a hex on the outer diameter of the inside of the
fitting it is only just feelable with my fingers, the bore of the
internal part is smooth and there appears to be no way to hold it in
place while I apply a loosening action to the external hex.

Any bright ideas on how to slacken it off so I can fit a new washer?

Before anyone suggests it I have considered using an angle grinder but
the flange is in a stainless steel tank and even though it is vented
and operating at atmospheric pressure I am really reluctant to start
hacking access holes in it.

P.S. Do they make 'internal' stillsons ? :)


--

Harry Bloomfield

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Apr 12, 2010, 2:46:10 PM4/12/10
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The Other Mike formulated on Monday :

> Before anyone suggests it I have considered using an angle grinder but
> the flange is in a stainless steel tank and even though it is vented
> and operating at atmospheric pressure I am really reluctant to start
> hacking access holes in it.

I can only suggest the angle grinder solution :-)

Cut a hole in the tank (with the angle grinder) a suitable distance
from the flange to enable you to get some stillsons on and hold it.
Once the job is done, get a piece of stainless made up to bolt in place
and a gasket to reseal it.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


Grimly Curmudgeon

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Apr 12, 2010, 8:50:44 PM4/12/10
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We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember The Other Mike
<rootpa...@somewhereorother.com> saying something like:

>Any bright ideas on how to slacken it off so I can fit a new washer?

>P.S. Do they make 'internal' stillsons ? :)

Not that I know, but I've just thought of a tool.
A long pair of tongs with the gripping heads turned out and backwards,
so that you can fit them through the hole and grip the outsides of the
internal hex.

YAPH

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Apr 13, 2010, 12:23:16 AM4/13/10
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On Mon, 12 Apr 2010 17:58:47 +0100, The Other Mike wrote:

> Before anyone suggests it I have considered using an angle grinder but
> the flange is in a stainless steel tank and even though it is vented
> and operating at atmospheric pressure I am really reluctant to start
> hacking access holes in it.

I wouldn't suggest hacking a hole in the cylinder but if you cut two slots
in diametrically opposite sides of the hex you can split it and remove it,
and fit a new flange. (Standard procedure for removing bath wastes that
have been welded on by decades-old boss white.) I'd use something a little
more delicate than an angle grinder, though - at least for the final
couple of millimetres, so you don't damage the cylinder itself. A
multitool would be my choice (because I've got one! :-))

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

If a tree falls in a forest, can one hand hear it clap?

The Other Mike

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Apr 13, 2010, 5:59:58 AM4/13/10
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Possible mileage in that one, been also thinking about an expanding
blind bearing remover but all the ones I have are too small, or a
piece of metal, maybe a tube to reduce the heat needed, temporarily
soldered into the internal diameter with a suitable means of holding
it.

--

The Other Mike

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Apr 13, 2010, 6:01:04 AM4/13/10
to
On 13 Apr 2010 04:23:16 GMT, YAPH <use...@yaph.co.uk> wrote:

>On Mon, 12 Apr 2010 17:58:47 +0100, The Other Mike wrote:
>
>> Before anyone suggests it I have considered using an angle grinder but
>> the flange is in a stainless steel tank and even though it is vented
>> and operating at atmospheric pressure I am really reluctant to start
>> hacking access holes in it.
>
>I wouldn't suggest hacking a hole in the cylinder but if you cut two slots
>in diametrically opposite sides of the hex you can split it and remove it,
>and fit a new flange. (Standard procedure for removing bath wastes that
>have been welded on by decades-old boss white.) I'd use something a little
>more delicate than an angle grinder, though - at least for the final
>couple of millimetres, so you don't damage the cylinder itself. A
>multitool would be my choice (because I've got one! :-))

The only problem with that approach is that there is no way of getting
a new internal ring into the tank. The biggest opening is where the
immersion heater fits, the largest other opening is around 1.5"
diameter.

Rather than destructively splitting the ring, maybe a couple of pieces
of brass silver soldered onto the inner ring that I could hold with a
piece of flat bar would work. Why no one thought to provide some
means of holding this ring stationary from the outside I'll never
know, maybe the designer somehow thought that it would never leak!

--

Grimly Curmudgeon

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Apr 13, 2010, 7:19:44 AM4/13/10
to
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember The Other Mike
<rootpa...@somewhereorother.com> saying something like:

>Rather than destructively splitting the ring, maybe a couple of pieces


>of brass silver soldered onto the inner ring that I could hold with a
>piece of flat bar would work.

As is moulded in to many smaller tank fittings. Annoyingly, some of them
don't, either.

>Why no one thought to provide some
>means of holding this ring stationary from the outside I'll never
>know, maybe the designer somehow thought that it would never leak!

Lack of foresight and the saving of a few grams of brass.

Another idea, involving an angle grinder.

Cut a 6mm deep slot across the inner (this might entail also cutting the
outer, but no real matter) so that you have a pair of detents that you
can fit a flat bar into. The bar is cut just long enough to sit into the
inner but not the outer. Grip it firmly or weld on a handle and undo the
outer.

The Other Mike

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Apr 13, 2010, 2:06:06 PM4/13/10
to

There is next to no thickness on the diameter of the inner ring to
provide any useful support , it's basically the thread depth and 'a
bit' , maybe 1/8 inch thick in total, which given the maximum
diameter of the immersion element is no more than about an inch is yet
another bit of brilliant design.


--

YAPH

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Apr 13, 2010, 6:02:07 PM4/13/10
to
On Tue, 13 Apr 2010 11:01:04 +0100, The Other Mike wrote:

> The only problem with that approach is that there is no way of getting
> a new internal ring into the tank. The biggest opening is where the
> immersion heater fits, the largest other opening is around 1.5"
> diameter.

How did they get it in in the first place?

Rather than trying to unscrew it I'd be inclined to try to fill the gap
that the washer is now failing to do with some sort of thread (or wire)
and adhesive/sealant mixture, so that the thread progressively pushes the
surfaces apart (the way winding string or wool around your hand, even
loosely, ends up uncomfortably tight), while the adhesive/sealant - er -
adheres and seals. The question then becomes what materials to use?


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

Thesaurus: extinct reptile noted for its wide vocabulary.

Grimly Curmudgeon

unread,
Apr 13, 2010, 9:18:53 PM4/13/10
to
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember The Other Mike
<rootpa...@somewhereorother.com> saying something like:

>There is next to no thickness on the diameter of the inner ring to


>provide any useful support , it's basically the thread depth and 'a
>bit' , maybe 1/8 inch thick in total, which given the maximum
>diameter of the immersion element is no more than about an inch is yet
>another bit of brilliant design.

Oh, it's a small one. Damn, I thought it was a 2" jobbie.

The Other Mike

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Apr 15, 2010, 5:35:35 AM4/15/10
to
On 13 Apr 2010 22:02:07 GMT, YAPH <use...@yaph.co.uk> wrote:

>On Tue, 13 Apr 2010 11:01:04 +0100, The Other Mike wrote:
>
>> The only problem with that approach is that there is no way of getting
>> a new internal ring into the tank. The biggest opening is where the
>> immersion heater fits, the largest other opening is around 1.5"
>> diameter.
>
>How did they get it in in the first place?

By welding it together after the flange was fitted. Short of the aid
of scotty and a beam me up machine it has to have been done like that.
Foldable memory metal that looks and acts like brass hasn't yet been
invented :)

>Rather than trying to unscrew it I'd be inclined to try to fill the gap
>that the washer is now failing to do with some sort of thread (or wire)
>and adhesive/sealant mixture, so that the thread progressively pushes the
>surfaces apart (the way winding string or wool around your hand, even
>loosely, ends up uncomfortably tight), while the adhesive/sealant - er -
>adheres and seals. The question then becomes what materials to use?

I've smeared LS-X on it and that is ok for a temporary repair for a
few days but it leaks again with any movement with heat and vibration.
I suppose I could dig the cork seal out completely and then wind in
some hemp and boss white but I'd prefer a permanent repair that I know
will last or at least a modification to the inner ring so that it can
be removed easily in the future.


--

The Other Mike

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Apr 20, 2010, 3:24:57 PM4/20/10
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Finally got it removed.

I soft soldered a couple of 10mm lengths of 6mm diameter brass on the
inner bore. I held the inner ring in place with a suitable tool (a
jammed in copper and hide mallet!) and used a G clamp to rotate the
outer part of the boss - my stillsons didn't fit, and the immersion
sided hex is behind the circular flange the immersion element fits
into. Just thankful the threads were clean and not full of compound
so very little effort needed to undo.

On removal I discovered the inner ring had only two spanner flats and
was thinned down to about 2mm thick on the tank side. There was an
offset full width 3mm high slot cut across the stainless tank circular
cutout and so the inner ring could be retrieved to the outside.

I suppose the tank might have been welded before the flange was
fitted, how it was held is anyones guess, but it sure wasn't designed
for easy maintenance.

--

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