IMPROVEMENTS IN SAFETY VALVES
Year: 1870

page_text: LETTERS PATENT to John Addy Hopkinson and Joseph Hopkinson,
junior, both of Huddersfield, in the County of York, Engineers, for
the Invention of "IMPROVEMENTS IN SAFETY VALVES."
.
Sealed the 21st February 1871, and dated the 10th November 1870.
PROVISIONAL SPECIFICATION left by the said John Addy Hopkinson
and Joseph Hopkinson at the Office of the Commissioners of Patents,
with their Petition, on the 10th November 1870.
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, junior, both of
Huddersfield, in the County of York, Engineers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN SAFETY VALVES," to be
as follows:-
. Our Invention relates to safety valves of the dead weight construction,
and has for its object an increased and compound discharging power on
any given diameter of block or valve seating fixed upon a steam boiler or
other vessel requiring relief from pressure, and by which are or may
be obtained a number of open discharging areas, surfaces, or circum-
ferences, with a combined weight equal to that required for a single

page_text: valve of the same diameter as that of the largest of the series used
on this construction. For this purpose we place a valve of the ball or
other suitable shape of surface upon the block or lowest valve seating,
which valve is weighted by a dead or pendulous weight to the pressure
required. On the top of this valve which forms the seat for another, a
second valve of suitable shape is placed and weighted in a similar manner
by a pendulous or dead weight. On this second valve is placed a third
valve of suitable shape, weighted also in a similar manner, which
principle of weighting and seating valves one upon another may be con-
tinued as far as may be considered requisite. Each valve although of
different diameters may be made to present either an equal or a
differential area or surface to the pressure acting upon them respectively,
but which in all cases will be suitably weighted according to the area so
presented. By this arrangement three or more valves may be weighted
with the same weight as for one valve of the largest diameter used.
The next part of our Invention relates to the same arrangement of
valves, but instead of using a dead or pendulous weight we employ an
arrangement of spring or springs, either compressed or distended above
or below the valves as desired, but in all cases arranged so as to allow
the valves to rise separately from their respective seatings witliout
affecting their independent action, or bringing strain upon the springs
belonging to another valve.
And our Invention also consists in the construction of any number of
valves of any given area seated one upon another with valve faces of
any suitable shape, and of diameters equal to or only minutely different
from each other. By placing a dead weight or compressed or distended
spring or springs on the uppermost valve all the valves are weighted by
one dead weight or spring or springs, as before mentioned, just as would
be required for only one valve.
This arrangement may also be carried to such an extent as to pro-
vide any number of outlets or discharges which in practice may be deemed
necessary.
And, lastly, any one or more of the said valves may also be made to.
act in case of deficiency of water by being placed in connection with a
float within the boiler shall raise it or them from its or their seat or
seats in case of the water falling below a fixed level.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Addy Hopkinson and Joseph Hopkinson in
the Great Seal Patent Office on the 9th May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
ADDY HOPKINSON and JOSEPH HOPKINSON, junior, both of Huddersfield,
in the County of York, Engineers,, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of November, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said John Addy Hopkinson and Joseph Hopkinson,
junior, Her special licence that we, the said John Addy Hopkinson
and Joseph Hopkinson, junior, our executors, administrators, and
assigns, or such others as we, the said John Addy Hopkinson and Joseph
Hopkinson, junior, 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 SAFETY VALVES," upon the condition (amongst
others) that we, the said John Addy Hopkinson and Joseph Hopkinson,
junior, our executors or administrators, by an instrument 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 I, the said Joseph Hopkinson, junior, on.
behalf of myself and of the said John Addy Hopkinson, 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, reference being had to the Drawings here-
unto annexed and to the letters and figures marked thereon (that is to
say) :-

page_text: and compound discharging power on any given diameter of block or
valve seating fixed upon a steam boiler or other vessel requiring relief
from pressure, and by which are or may be obtained a number of open
discharging areas; surfaces, or circumferences with a combined weight
equal to that required for a single valve of the same diameter as that of
the largest of the series used on this construction.
.
And in order to show more distinctly what is the object of our
Invention, we would state that while it is well known to be the
essential requirement of a safety valve to relieve a boiler of the surplus
pressure over and above that to which it is weighted, it has been the
practice hitherto, in order to attain even an approximate measure of
adequate relief, to use either valves of large diameter or several valves
placed upon one boiler. Now the object of our Invention is to obviate
these inconveniences by increasing the number of discharging areas,
surfaces, or circumferences without increasing the diameter of the valve,
or the weighting or holding down power required. For this purpose we
place a valve of the ball or other suitable. shape of surface upon the
block or lowest valve seating, which valve is weighted by a dead or
pendulous weight to the pressure required. On the top of this valve,.
which forms the seat for another, a second valve of suitable shape is
placed, and weighted in a similar manner by a pendulous or dead weight..
On this second valve is placed a third valve of suitable shape, weighted
also in a similar manner, which principle of weighting and seating valves
one upon another may be continued as far as may be considered requisite.
Each valve (although of different diameters) may be made to present
either an equal or a differential area or surface to the pressure acting
upon them respectively, but which in all cases will be suitably weighted
according to the area so presented. By this arrangement the whole
safety valve is composed of three or more valves weighted with the same
weight as for one valve of the largest diameter used. Or two valves
only with two discharges may be used, but a safety valve composed of
three separate valves at the least is preferred.
The next part of our Invention relates to the same arrangement of
valves, but instead of using a dead or pendulous weight we employ an
arrangement of spring or springs, either compressed or distended, above
or below the valves as desired, but in all cases arranged so as to allow
the valves to rise separately from their respective seats without affecting
their independent action or bringing strain upon the springs belonging

page_text: to another valve. Safety valves of this construction may be applied to
locomotive, marine, or portable boilers.
.
And our Invention also consists in the construction of any number of
valves of any given area seated one upon another with valve faces of any
suitable shape, and of diameters equal to or only minutely differing from
cach other. By placing a dead weight or compressed or distended spring
or springs on the uppermost valve all the valves are weighted or held
down by one dead weight or spring or springs as before mentioned, just
as would be required for only one valve. This arrangement may also be
carried to such an extent as to provide any number of outlets or
discharges which in practice may be deemed necessary.
And, lastly, any one or more of the said valves may also be made to
act in case of deficiency of water by being placed in connection with a
float within the boiler which shall raise it or them from its or their scat
or seats in case of the water falling below a fixed level.
Having thus stated the nature of the said Invention we will
proceed to describe more particularly in what manner the same is to be
performed by the aid of the accompanying Drawings, in which are
represented safety valves constructed and arranged so as to be weighted
by pendulous weights and also by springs in the manner referred to.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a vertical section and Fig. 2 is a plan or horizontal view of
three differential arcá valves arranged so as to be weighted by pendulous
weights.
upon
B
A is the valve seating; B is the valve of largest diameter of the three
set on the fixed seating; C is a valve of less diameter than B set
as a seating; and D is the third valve set upon C as a seating; E, E, is
a bonnet on which is placed the dead weight for weighting the valve C
to the required pressure; and F, F, is a similar bonnet to carry the
weight for the valve B. These two valves B and C are arranged for
being externally weighted and the valve D internally weighted by a
weight suspended from the central rod G; but this valve D may also be
externally weighted. if preferred. The valves can be arranged to any
suitable diameter or size, and separately weighted to the respective areas
presented for pressure.
Fig. 3 is a vertical section and Fig. 4 a plan or horizontal view shew-
ing five separate. valves seated one upon another. A is the fixed scating

page_text: for the bottom valve B. In this case the valves. F*, E, and C are
weighted in the manner shewn in Fig. 1. D and B are intermediate
valves arranged to give extra circumference or discharging power with-
out requiring extra weight. The arrangement of these valves may be
modified to suit circumstances.
Fig. 5 represents in vertical section three valves similar to those
shown in Fig. 1, but with the external weights at H, H.
In this case
the valves are covered with a dome casting and the three flanges of the
block I; the valve K and the dome L are all bolted together by one
bolt passing through all three flanges. This is shown on an enlarged
scalc in Fig. 6.
Fig. 7 is an elevation shewing the external enclosure of the valve on
the boiler, and which enclosure can be made to any design or pattern
preferred.
Fig. 8 is a vertical section shewing three valves of equal or slightly
differential area having only one weight M, and that suspended by a
central rod G from the uppermost valve D, which weight is sufficient to
weight the whole of the three valves. This arrangement admits of the
use of either a greater or less number of valves than is here shewn, and
the valves may be weighted either externally or internally by a weight
or weights applied to the uppermost valve of the series.
Fig. 9 is a vertical section, Fig. 10 an elevation, and Fig. 11 a plan
or horizontal view shewing three valves weighted by means of a
spring N, instead of by dead weights.
Fig. 12 is a half elevation and half vertical section shewing three
valves, each weighted by a separate spring in such a manner that cach
valve may discharge separately without bringing strain on the spring of
another valve. For this purpose the valve B, resting on the fixed seat A,
is secured thereto as required by means of the spring N¹ connected to
the flange O, which is pressed upon and confined by the adjustable :
nut P, which can be raised or lowered on the flange K, thereby weight-
ing the valve B to any required pressure. Then again the valve C
resting on the valve B as its seating is secured thereto as required by
means of a spring N² connected to the flange Q, which is pressed upon
and confined by the adjustable nut R, which nut can be raised or a
lowered on the guard and flange S. Then, again, the valve D, resting
on the valve C, is secured to its seating thereon as required by means.

page_text: of a spring N³, and connected to the flange T, and acted upon bỷ the
nut U adjustable on the guard and flange V.
It will here be observed that each of the valves B, C, and D is
separately weighted by its own spring N¹, Nº, or N³, and can be adjusted
as to pressure or weighting without interfering with. the spring or
weighting power applied to either of the other valves.
Fig. 13 is a section shewing the upper part of a boiler with a low-
water float adapted and applied to a set of valves in such a manner as
to admit of its raising one of the valves in case of the water in the
boiler falling below a fixed level, thereby affording a security against
boiler explosions.
The several arrangements of dead weight safety valves herein-before
described will serve to illustrate the broad feature or principle of our
Invention, which is to increase the discharging power of safety valves
by a multiplication or compound arrangement of open discharging areas,
surfaces, or circumferences, one over another, thereby utilizing in an
increased degrée the amount of dead weight or holding down power
applied to a valve of a given diameter and area, and also giving to the
valves increased freedom to rise from their seats.
And the above described arrangements of valves may be varied as to
form and as to the number of valves in the series without departing
from the said broad feature or principle of our Invention.
Having thus described the nature of the said Invention, and in what
manner the same is to be performed, we hereby declare that what
we claim as of our Invention is,-
First. The arrangement and weighting or holding down of safety
valves by placing two or more valves so as to seat one upon another,
and provide discharges from or at all their circumferences for the relief
of pressure as herein-before described.
Secondly. The arrangement of two or more valves placed so as to scat
one upon another, and weighted or held down by one or more dead
weights, having also one or more intermediate valves not strictly in
connection with the dead weight proper, but pressed to its or their seat
or seats by the weight connected to another valve seated directly upon
it or them or to another valve above, so as to provide discharges from
or at all the circumferences without requiring the application of a dead
weight to cach separate valve.

page_text: Thirdly. The arrangement and weighting or holding down of two or
more valves placed so as to seat one upon another, and weighted or held
down by one dead weight or spring, as herein-before described.
Fourthly. The arrangement of holding down two or more valves
placed so as to seat one upon another by means of springs, as hercin- f
before described.
Fifthly. The weighting or holding down of two or more valves seated
one upon another by means of a dead weight or weights or a spring or
springs, or a combination of dead weight and springs.
Sixthly. The means of securing the valve against tampering by en- 1
closing it in a dome or casing fastened down to the block in the manner
described.
And lastly. The adaptation and application to this kind of valve of a
lever and float for the purpose described.
In witness whereof, I, the said Joseph Hopkinson, junior, have 1
hereunto set my hand and seal, the Ninth day of May, in the
year of our Lord One thousand eight hundred and seventy-
one.
JOSEPH HOPKINSON, JUNIOR. (L.S.)
Witness,
WILLIAM SPENCE,
8, Quality Court,
Chancery Lane.