IMPROVEMENTS IN SELF-ACTING SAFETY VALVES FOR STEAM BOILERS
Year: 1869

page_text: LETTERS PATENT to George Douglas Hughes and Alfred Hardy
Sellers, both of Nottingham, in the County of Nottingham, for the
Invention of "IMPROVEMENTS IN SELF-ACTING SAFETY VALVES FOR STEAM
BOILERS."
Sealed the 23rd July 1869, and dated the 9th April 1869.
PROVISIONAL SPECIFICATION left by the said George Douglas Hughes
and Alfred Hardy Sellers at the Office of the Commissioners of
Patents, with their Petition, on the 9th April 1869.
We, GEORGE DOUGLAS HUGHES and ALFRED HARDY SELLERS, both
of Nottingham, in the County of Nottingham, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN SELF-ACTING SAFETY
VALVES FOR STEAM BOILERS," to be as follows:-
This Invention relates to improvements in the construction of self-
acting safety valves for steam boilers, and consists of a spherical or ball
valve loaded by a dead weight suspended to the valve by means of a rod
within the boiler.

page_text: In conjunction with the spherical valve an additional valve is applied,
either spherical, mushroom-shaped, or flat, hung on a weighted lever
acting on the valve by a joint and fulcrum, such lever and weight being
free of access or outside the boiler. We propose to make the base for
such valve or valves of cast iron with suitable gun-metal or other
seatings, and to form one or more circular or other shaped passages or
conduits to convey all or any portion of steam escaping from the dead
weight valve by a suitable pipe or pipes to and through the crown plate
or plates of boiler furnace or furnaces directly over and on to the fires,
or to any other part of such furnaces of steam boilers, and by these
means to damp or entirely extinguish the fires of such furnaces. We
propose to actuate the dead-weighted valve or valves by a lever working
on a fulcrum inside the boiler, such lever passing through a slot or eye
in the rod carrying the dead weight, one end of such lever being
provided with a float to rise and fall with the level or surface of the
water in the boiler, and in falling through deficiency of water to act on
and raise the rod and weight of said valve or valves, and by these means
to permit the steam to be blown on the fires and damp or extinguish
them, thus preventing any liability of collapse or injury to the flues or
any other parts of steam boilers, the steam escaping from such valve
or valves through excess of pressure being conveyed through the pipes
and passages directly into the furnace, thus preventing explosion or
collapse from over pressure or deficiency of water.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said George Douglas Hughes and Alfred Hardy Sellers 2
in the Great Seal Patent Office on the 31st July 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
DOUGLAS HUGHES and ALFRED HARDY SELLERS, both of Nottingham.
in the County of Nottingham, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 3
Letters Patent, bearing date the Ninth day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said George Douglas Hughes and Alfred
Hardy Sellers, Her special licence that we, the said George Douglas

page_text: Hughes and Alfred Hardy Sellers, our executors, administrators, and
assigns, or such others as we, the said George Douglas Hughes and
Alfred Hardy Sellers, our 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 "IMPROVEMENTS IN SELF-ACTING SAFETY VALVES FOR STEAM BOILERS," upon
the condition (amongst others) that we, the said George Douglas Hughes
and Alfred Hardy Sellers, our executors or administrators, by an instru-
ment in writing under our, or their, or one of their hands and seals, should
particularly 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 we, the said George Douglas Hughes and
Alfred Hardy Sellers, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Our Invention has for its object the application of a self-acting
apparatus to land, marine, locomotive, or other steam boilers for the
prevention of explosion, collapse, or injury to the outer shells, flues, or
furnace crowns from deficiency of water or from over pressure.
To effect these objects we make and attach to the boiler externally or
internally an apparatus consisting of a casting forming a box, chamber,
or hollow vessel containing one or more valves, one of which valves we
propose to make of a spherical, conical, or other suitable form to be
fitted into and supported upon a seating of similar form perfectly steam-
tight when down upon the face. To this valve we attach a dead weight
by means of a rod fixed to the centre of the valve, such dead weight to
be so arranged that it shall balance the pressure of steam upon the under
surface of the valve to the pressure per square inch at which the boiler
may safely be worked, or at any other lower pressure that may be
required. From this box, chamber, or vessel we convey the steam
which may at any time escape from or through this valve from undue or
over pressure by means of one or more passages and pipes into the
furnace or furnaces of such boiler, thereby damping and eventually
extinguishing the fire or fires if the pressure in the boiler should continue

page_text: to increase so as to render this necessary to ensure its safety. Again, in
case of low water this valve and dead weight is raised by means of a
lever and float which is worked by the water in the boiler raising the
valve by means of the centre rod, which is slotted or fitted so as to be
coupled to the lever and float, whereby on the water becoming so low as
to be dangerous to the safety of the boiler the valve is lifted from the
face and the escaping steam passes down the passages and pipes, damping
or extinguishing the fire or fires in the same way as described for over
or excessive pressure. From this description it will be seen that so long
as the safe working pressure is not exceeded and the water is maintained
at the proper level this valve will remain upon its seating and at rest,
but so soon as the safe working pressure is exceeded, or any lower
pressure at which it may have been adjusted, or the water may have
become too low for safe working, in either case the valve will be raised
from its seating and the escaping steam will pass down the pipes into
the furnace or furnaces with greater force as the danger increases until
the fire or fires are quite extinguished. The valve being inaccessible
cannot be overloaded or tampered with by the attendant. In case of
applying this apparatus to new boilers or to boilers at work, but which
have no suitable safety valve, we attach to the casting a valve loaded
externally by means of a lever and weight in the ordinary way, this
valve to be used in connection with the other for working, and to be
accessible to the attendant at any time. In applying this apparatus to
steam boilers externally we prefer to attach it by riveting it to the shell
of the boiler when practicable, but we also attach it by bolts or in any
other suitable manner when riveting is not practicable. In the internal
arrangement we prefer to use one, two, or more studs for the purpose,
but this internal application may also be secured by rivets, bolts, or in
any other of the usual modes generally practised.
In order that our said Invention may be completely understood we
annex the accompanying three Sheets of Drawings, the following being
a description of the same.
In Sheet 1, Fig. 1 represents a transverse vertical section, and Fig. 2
a longitudinal vertical section of a Cornish two-flued boiler with the
apparatus attached; Figs. 3, 4, 5, are plans of top, middle, and bottom
sections of valve box seatings and valves; similar letters denoting

page_text: A represents the internally loaded valve shewn of spherical form (but
any other suitable form may be used) placed in a box or steam chamber;
B, B, B, B, are the steam passages and pipes connected thereto, and
communicating with the furnaces C, C; D is the dead weight suspended
by the rod E (slotted in this case), which is attached to the valve A by
means of the centre screw and nut on the end of the rod; this weight D
will therefore be raised when the pressure on the under side of the valve
exceeds that of the weight, thus allowing the steam to escape into the
box or chamber, and thence down the passages and pipes B, B, into the
furnaces C, C. Again, F is a float suspended at one end of the lever G,
and balanced on the surface of the water by means of the balance
weight H at the other end of the lever. This lever is suspended by the
joint P (which also serves as its fulcrum), and passing through the slot
in the rod E raises the valve A as the float descends with the water
level, allowing the steam to escape into the box or chamber and down
the pipes B, B, into the furnaces in the same manner as described for
over pressure. In connection with this valve is the externally loaded
valve, as before described, where I is the valve, M the lever, and N the
weight, by means of which the pressure may be regulated to any extent
lower than that at which the dead weight valve is adjusted. The steam
escaping from this valve passes through the opening O into the open air
in the usual manner as from an ordinary safety valve.
In Sheet 2, Figs. 1 and 2 represent in similar sections the apparatus
as attached to a plain externally fired egg-ended boiler without internal
flues; the same letters refer to the same parts as in Sheet 1; these
Figures shew the apparatus without the common or ordinary lever valve
attached; Fig. 3 is a plan view of top section of valve box.
In Sheet 3, Figs. 1 and 2 shew similar sections of the apparatus as
fixed internally, and which can in like manner be applied to boilers of
any form; it may be attached by studs, as shewn in the Drawings, or
by any other of the usual means adopted, as already described; the same
letters refer to the same parts as in Sheets 1 and 2. Fig. 3 is a hori-
zontal section shewing the valve A and diverging pipes B, B, to the
furnaces C, C, Fig. 4 shewing top plan view of valve and pipes, as
before.
Having now described the nature of our said Invention, and the
manner in which the same is to be carried into practical effect, we
would remark in conclusion, that we do not limit ourselves to the precise

page_text: details or configuration or position of parts which we have expressed and
shewn, as the same may obviously be modified and varied without in
any degree departing from the principles, purposes, and objects on and
for which the Invention is based and intended; but what we claim and
desire to be secured to us by the herein in part recited Letters Patent
is, the novel arrangement and application to steam boilers of a spherical
or other form of dead or otherwise weighted valve actuated by the steam
pressure for over pressure, and by the lever and float for low water,
thus constituting self-acting safety valves, the escaping steam in either
case being conveyed or conducted into the furnace or furnaces by means
of suitably constructed steam passages and pipes, thereby damping or
extinguishing the fire or fires and consequently preventing explosions,
collapse, or injury to steam boilers, substantially as herein specified and
shewn by the Drawings annexed.
In witness whereof, we, the said George Douglas Hughes and Alfred
Hardy Sellers, have hereunto set our hands and seals, this Twenty-
eighth day of July, in the year of our Lord One thousand eight
hundred and sixty-nine.
Witness,
EDWARD CARVER,
GEORGE DOUGLAS HUGHES. (L.S.)
ALFRED HARDY SELLERS.
(L.S.)
Nottingham.