IMPROVED MEANS OF PREVENTING THE EXPLOSION OF STEAM. BOILERS
Year: 1856

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents.
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the.
Invention of "IMPROVED MEANS OF PREVENTING THE EXPLOSION OF STEAM.
BOILERS." A communication from M. Edward Scrive, of Lille, in the
Empire of France.
-
Sealed the 9th June 1857, and dated the 30th December 1856.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
30th December 1856.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVED MEANS OF PREVENTING THE EXPLOSION OF
STEAM BOILERS," to be as follows:-
This Invention consists in the employment of a metal or an alloy of metals
which is fusible at a moderate temperature, for making a valve or stopper
attached to a tube or pipe communicating with the inside of a steam boiler.
This fusible metallic valve or stopper will be plunged in and covered by the
water in the boiler or steam generator, and will be preserved by the com-
paratively low temperature of the water, and will therefore be prevented from
melting; but immediately that the fusible metal is uncovered, by the water in
the boiler sinking below a certain level, it will be melted by the heat developed

page_text: from the naked sides of the boiler which are in contact with the heated vapor
in the flue; and by the fusible metal valve or stopper being thus destroyed an
opening will be made into the tube to which, it is attached, and the steam
allowed to escape from the boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office on
the 30th June 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of December, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Edward Newton, Her special license that I, the said William
Edward Newton, my executors, adiñors, and assigns, or such others as I,
the said William Edward Newton, my executors, administrators, and assigns,
should at any time agree with, and no others; from time to time and at all
times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVED MEANS OF PREVENTING THE EXPLOSION OF STEAM BOILERS," being a
communication from M. Edward Scrive, of Lille, in the Empire of France,
upon the condition (amongst others) that I, the said William Edward
Newton, by an instrument in writing under my hand and seal, should par-
ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
The object of this Invention is to prevent the explosion of steam boilers
caused by a deficiency of water, whereby the boiler becoming red hot will be

page_text: liable to explode when a fresh supply of water is introduced, or will be unable
to resist the undue pressure put upon it by the sudden expansion of the steam.
This will also be the case when on opening any of the cocks or valves motion is
communicated to the water which had been kept still by the pressure of the
steam.
The object of the Invention is effected by the employment of a valve or
stopper made of a metal or an alloy of metals which is fusible at a moderate
temperature, the valve or stopper being attached to a tube or pipe commu-
nicating with the inside of the steam boiler. This fusible metallic valve or
stopper will be plunged in or covered by the water in the boiler or steam
generator, and will be preserved by the comparatively low temperature of the
water, and will therefore be prevented from melting; but immediately that the
fusible metal is uncovered, by the water in the boiler sinking below a certain
level, it will be melted by the heat developed from the naked sides of the boiler
which are in contact with the heated vapor in the flue; and by the fusible
metal valve or stopper being thus destroyed an opening will be made into the
tube to which it is attached, and the steam allowed to escape from the boiler.
In order to give timely notice to the attendant that a supply of water is required,
and thus avoid the danger of explosion, I cause this escaping steam to act upon
a whistle attached to the apparatus.
The Figures in the accompanying Drawing represent the arrangement of
apparatus which the Inventor prefers to employ for carrying the Invention
into effect.
Fig. 1 is a transverse vertical section of a boiler with the improved apparatus
adapted thereto; Fig. 2 is a side view of the apparatus détached, and drawn on
an enlarged scale; and Fig. 3 is a front view of the same on a larger scale.
Similar letters denote corresponding parts in all these Figures.
A is a disc, of copper or brass or other suitable metal, bolted to the boiler at
G, and having a rod or projection K cast on it outside, in direct contact with
the flue E, containing the products of combustion, by which the heat there-
from is communicated to the safety apparatus inside the boiler. On the inner
side of the disc A is cast a projecting piece A', 'having a plate M of tin, or other
inoxidizable metal fusible at a low temperature, screwed on to it at L, L.
B is a copper pipe for the escape of the steam; this pipe passes up through the
boiler, as seen in Fig. 1, and is jointed at C to another pipe D, to which is
attached in any convenient and suitable manner the alarm whistle outside the
boiler. As long as the water in the boiler is maintained at the required level
(as shewn, for example, at J, J, Fig. 1), that is to say, as long as it does not sink
below or uncover that part of the boiler which is opposite the flues E, E, the

page_text: fusible metal plug or disc is protected by the water from being melted; but on
the level of the water sinking and uncovering the apparatus the heated gases
and products of combustion in the flue will, through the rod or piece K, which
projects into the flue, raise the temperature of the disc A to about their own
temperature, and as the fusible plate will melt at a much lower temperature,
the fusion of this plate will take place long before the boiler has attained a
dangerous heat. On the fusible plate melting free passage will be opened for
the steam, which will escape through the pipes B and D, and by rushing through
the whistle will sound the alarm.
Fig. 4 is a transverse vertical section of a boiler, shewing a modification of
the above plan, and in which the safety apparatus with the fusible metal or
alloy is placed outside the boiler, so that it may be got at more easily when it is
required to put in a new fusible plug or disc. B is a short tube communicating
with the interior of the boiler, and projecting from one of the sides thereof into
one of the side flues. At the upper end of this tube is a socket C, which is
screwed to receive the end of a vertical pipe E, at the bottom of which is placed
the fusible metal plug or disc, asseen at D. As long as the water in the boiler
remains above the level of the apparatus the short pipe B will be filled with
water, and the fusible plug or disc D will be kept at a comparatively low tem-
perature; but immediately the level of the water sinks so low as to allow the
water to run out of the pipe B, and leave the disc D exposed to the action of
the heat in the flues the disc will melt and allow the steam to escape, and in
so doing cause a whistle attached to the vertical pipe E to sound an alarm. It
will be easily understood that when it is required to replace the melted fusible
dise or plug with a fresh one, this may be done with facility by simply un-
screwing the pipe E and placing the fresh disc either at the end of the pipe E
or in the socket C.
Having now described the Invention of improved means of preventing the
explosion of steam boilers, that has been communicated to me by my foreign
correspondent as aforesaid, and having explained the manner of carrying
the same into effect, I would observe, in conclusion, that I am aware that
fusible metal applied in various ways has heretofore been adapted to steam
boilers to prevent explosions; I do not, therefore, mean to claim the exclusive
right to employ fusible metal or alloys of metals for the above purpose, except
when it is applied substantially in the manner herein shewn and described; and
I claim as the Invention secured to me by Letters Patent as aforesaid, the
mode or modes herein described of applying fusible metal or alloys of metals to
steam boilers, so that the metal or alloy may be melted when by the sinking
of the level of the water the said metal or alloy of metal becomes exposed to

page_text: such an increased temperature as would be liable to cause an explosion of the
boiler, as is well known.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Twenty-ninth day of June, in the year of
our Lord One thousand eight hundred and fifty-seven.
Witness,
J. W. MOFFATT,
.66, Chancery Lane.
W. E. NEWTON. (L.S.)