IMPROVE- MENTS IN PACKINGS FOR STEAM AND OTHER JOINTS EXPOSED TO FLUIDS AT HIGH TEMPERATURE
Year: 1884

page_text: I, WILLIAM JOHN ADAMS, of 35 Queen Victoria Street, in the County of
Middlesex, Engineer, do hereby declare the nature of my Invention for "IMPROVE-
MENTS IN PACKINGS FOR STEAM AND OTHER JOINTS EXPOSED TO FLUIDS AT
HIGH TEMPERATURE" and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My improved packing is principally composed of a compound of asbestos and
caoutchouc in conjunction with woven or loosely felted fabric, by preference of
asbestos; the various component parts being combined as hereinafter described.
I am aware that various combinations of asbestos and caoutchouc have been used
for packings; also that the use of such materials, either separately or compounded
together, has been proposed in conjunction with certain fibrous materials, woven
fabrics, wire gauze &c. None of these packings are however entirely reliable for
the following reasons amongst others. With the asbestos and caoutchouc compound,
the asbestos being in a triturated state, there is a want of tenacity in the product;
the result being that the packing is liable to be blown out from the joint by the
pressure of the steam or other fluid. If the asbestos be woven into a sheet and
served with caoutchouc to make it impervious to moisture, the packing is wanting
in elasticity and is only suitable for use with true and accurately fitting faces.
Where again the compound is combined with cotton, hemp, flax or other fibrous
fabrics of a combustible nature, the latter, when exposed to heat, soon become
carbonised; and the packing losing tenacity, fails.
According to my improved mode of manufacture, I employ a compound of
triturated asbestos and caoutchouc in approximately equal quantities, and add a
suitable proportion of sulphur for accomplishing the subsequent vulcanizing process.
This compound having been thoroughly incorporated by the usual means, I roll it
into sheets. I then take a sheet of coarsely woven or loosely felted asbestos and
lay same on the sheet of asbestos and caoutchouc compound; another sheet of the
latter being then superposed on the asbestos sheet. These operations are repeated
according to the thickness of packing required to be produced. The multiple sheet
is then rolled so as to render the whole compact and to cause the lamina of asbestos
and caoutchouc compound to penetrate the intervening sheet or sheets of woven
or felted asbestos and to connect with each other from opposite sides of the latter
מ'

page_text: through the interstices of the fabric. The product having been vulcanized may
then be cut into washers or strips according to the purpose for which the packing
is required; or the vulcanizing process may be applied subsequently.
For making washers applicable, for example, to pipe joints, a modification of the
process of manufacture described may be employed. For such a purpose, the
sheets of asbestos and caoutchouc compound and sheets of felted or woven asbestos
may be alternately wrapped on a mandril until a thickness corresponding with the
width intended for the washer is attained. After rolling, the tube, formed as
described, may be cut into short lengths corresponding with the thickness desired
for the washer.
According to another modification particularly adapted to the manufacture of
thin packings, instead of primarily rolling or forming the asbestos and caoutchouc
compound into sheets, which would necessarily in such cases be very slight and
fragile, I spread the compound at once upon the asbestos fabric and I prefer to
serve or treat both sides of the latter simultaneously. This may be accomplished
by passing the said fabric vertically between two horizontal rolls, mounted at a
slight distance apart according to the thickness of the packing to be produced; the
upper sides of the said rolls being kept supplied with the asbestos and caoutchouc
compound in bulk. By these means each side of the asbestos fabric receives but a
thin serving or coating of the compound as distinguished from a sheet thereof as
produced by rolling.
Where, according to the modes of manufacture commonly in use, washers are cut
or punched out of sheets, the central and circumbscribing portions of the circles are
frequently wasted. Where however such packings are produced from unvulcanised
sheets manufactured according to my improved method, the portions referred to
may be worked up in the preparation of the sheets of asbestos and caoutchouc
compound; the pieces of felted or woven asbestos contained therein being of a
comparatively light and open texture and not calculated to produce serious
inequalities in the mass from which the asbestos and caoutchouc compound sheets
are rolled.
Packings manufactured according to the improved modes herein described
possess elasticity, tenacity and waterproof qualities, and are at the same time
capable of withstanding high temperature.
Having thus described the nature of my Invention and in what manner the same
is to be performed, I desire it to be understood that, although I have mentioned
triturated and fibrous asbestos as the best known material for the purposes herein
specified, I do not limit myself thereto as equivalent incombustible fibrous
substances may be substituted therefor; but I claim :-
The use, for steam and other joints, of packings composed of sheets or layers of
asbestos and caoutchouc compound alternating with and uniting from opposite
sides of a sheet or sheets of coarsely woven or loosely felted asbestos, combined
Bubstantially as described.
Dated this Eleventh day of Tal., 1001