IMPROVEMENTS IN SAFETY AND CHECK VALVE APPARATUS FOR STEAM BOILERS
Year: 1878

page_text: LETTERS PATENT to John Addy Hopkinson and Joseph Hopkinson, both of
the Firm of J. Hopkinson and Co., of Huddersfield, in the County of York,
Engineers, for the Invention of "IMPROVEMENTS IN SAFETY AND CHECK
VALVE APPARATUS FOR STEAM BOILERS."
Sealed the 17th September 1878, and dated the 19th March 1878.
PROVISIONAL SPECIFICATION left by the said John Addy Hopkinson
and Joseph Hopkinson at the Office of the Commissioners of Patents on the
19th March 1878.
JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of J. Hop-
kinson and Co., of Huddersfield, in the County of York, Engineers. "IMPROVE-
MENTS IN SAFETY AND CHECK VALVE APPARATUS FOR STEAM BOILERS."
The first part of our Invention relates to safety valves of steam boilers, and
consists in the combination of a safety valve with very simple apparatus, whereby
a very free discharge of steam from a boiler is ensured.
The Specification of former Latters Patent granted to the said Joseph Hopkinson,
dated 28th August, A.D. 1875, No. 3036, describes apparatus which comprises a
vessel containing mercury, and a mercurial column arranged in combination with
a lever connected with the valve, and one end of which lever carries the mercury
vessel or a float suspended in the same, while its other end is provided with a
weight; and by means of this apparatus the valve is controlled in the ordinary
manner solely by a weight until a pre-determined limit of pressure in the boiler is
exceeded, and then the diminution of the weight of mercury in the said vessel
will cause a very free discharge of steam.
According to our present Invention we obtain this very important result, namely,
the free discharge of the steam from the boiler by the employment of more simple
means than heretofore, as will be readily understood by the following description,
that is to say: We form the whole or a portion of the weight on the safety valve
of mercury, and so arrange the same in-connection with a column pipe and receiver
Drine S31

page_text: that at any pre-determined limit of pressure the mercury, which is exerting its
weight on the valve through the medium of a cup or holder, shall be forced by the
pressure out of this cup up the column .pipe into the receiver, thereby relieving the
valve of a portion of the weight to which it has been subjected, and permitting it
to rise freely from its seat; and the mercury or quicksilver thus made to form a
portion of the weight on the valve, and which at the discharging limit or maximum
pressure in the boiler is transferred from the valve to a suitable vessel or receiver,
is held or balanced by the steam while the pressure thereof exceeds its maximum
limit, thereby ensuring a very free discharge of steam from the boiler, but returns
and resumes its action on the valve in proportion to the diminution of this
pressure.
The safety valve may be of any suitable diameter and form.
According to one arrangement of our Invention we attach to the valve a rod or
stem which extends down therefrom, and is provided with a weight at its lower
end.
At any convenient distance from the valve we fix on the said rod a cup or
vessel of suitable capacity, and this cup is partially filled with mercury.
A column pipe is arranged with its lower extremity dipping into this cup, and
extends upward to any necessary height. The upper end of this pipe is provided
with a receiver into which the mercury is raised by the pressure, as above
specified.
In a modification of our Invention we employ a weight floating in the said cup
of mercury, and so arranged in connection with a stop or stops that at any fixed or
determined point this weight shall come in contact with the said stop or stops, and
coase to float, thereby taking weight off the valve; this weight, so long as it floats,
acts as dead weight upon the valve, and forms a part of the weight required to
press the valve down.
The second part of our Invention relates to an improved arrangement of the
check valves described in the Specification of our former Letters Patent dated 30th
December, A.D. 1876, No. 5057.
In this former Specification we have described an inverted check valve, that is
to say, a valve which is closed or pressed against its seat by the upward pressure
of a float in mercury, and also a modification in which the valve is pressed on its
seat by an annular weight in mercury, the mercury vessel and float being on the
egress side of the valve,"
But, according to our present Invention, we arrange the cup containing the
mercury below, and on the ingress side of the valve, thereby dispensing with the
annular construction of the weight or float, and at the same time so arrange the
valve that the excess or preponderance of the weight or gravity of the float and
valve over the buoyancy of the float in the mercury will tend to close the valve.

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 19th September 1878.
JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the Firm of J. Hop-
kinson and Co., of Huddersfield, in the County of York, Engineers. " IMPROVE.
MENTS IN SAFETY AND CHECK VALVE APPARATUS FOR STEAM BOILERS."
The first part of our said Invention relates to safety valves of steam boilers, and
consists in the combination of a safety valve with simple apparatus, whereby a very
free discharge of steam from a boiler is ensured.
The Specification of former Letters Patent granted to the said Joseph Hopkinson,
dated 28th August 1875, No. 3036, describes apparatus which comprises a vessel
containing inercury and a mercurial column arranged in combination with a lever
connected with the valve, and one end of which lever carries the mercury vessel
or a float suspended in the same, while its other end is provided with a weight;
and by means of this apparatus the valve is controlled in the ordinary manner,
solely by a weight until a pre-determined limit of pressure in the boiler is exceeded,
and then the diminution of the weight of the mercury in the said vessel will cause
a very free discharge of steam.
According to our present Invention we obtain this important result, namely, the
free discharge of the steam from the boiler by the employment of more simple
means than heretofore, as will be readily understood by the following description,
that is to say-We form a greater or lesser portion of the weight on the safety valve
of mercury, and so arrange the same in connection with a column pipe and receiver
that at any pre-determined limit or degree of pressure the mercury, which is exerting
its weight on the valve through the medium of a cup or holder, shall be forced by
the pressure out of this cup up the column pipe into the receiver, thereby relieving
the valve of a portion of the weight to which it has been subjected, and permitting
it to rise freely from its seat; and the mercury or quicksilver thus made to form a
portion of the weight on the valve, and which, at the discharging limit or maximum
pressure in the boiler, is transferred from the valve to a suitable vessel or receiver
is held or balanced by the steam while the pressure thereof exceeds its maximum
limit, thereby ensuring a very free discharge of steam from the boiler, but returns
and resumes its action on the valve in proportion to the diminution of this
pressure.
The safety valve may be of any suitable diameter and form.
In the accompanying Drawings,-
Figure 1 is a vertical section, shewing a portion of a steam boiler provided with
our improved apparatus.
Figure 2 shews also in vertical section a modification of the said apparatus.
A is the boiler; a is the block attached to the said boiler; and bis the safety
valve; c is a rod or spindle extending from the same, and which has fixed on it
a cup or vessel d containing mercury; e is the column pipe; fis the receiver.
According to the arrangement of our Invention, shewn in Figure 1, we attach to
the valve b a rod or stem c, which extends down therefrom, and is provided with
a weight g at its lower end.
At any convenient distance from the valve we fix on the said rod the cup or
vessel d of suitable capacity, this cup being partially filled with mercury.
The column pipe is arranged with its lower extremity dipping into this cup d,
and extends upward to any necessary height. The upper end of this pipe is pro-
vided with the receiver f, into which the mercury is raised by the pressure, as above
specified.
In the modification of our Invention, shewn in Figure 2, we employ a weight h
floating in the said cup of mercury, and so arranged in connection with a stop or

page_text: stops, as shewn at i, that at any fixed or determined point this weight shall come
in contact with the said stop or stops, and cease to float, thereby taking weight
from the valve; this weight, so long as it floats, acts as a dead weight upon the
valve, and forms a part of the weight required to press the valve down or to its
scat..
We have shewn this weight h annular, and with the lower end of the column
pipe extending down through its central aperture; we have also shewn the said
annular weight provided with a ring j fixed on the said weight in such a position
as to come in contact with adjustable screws, which form the stops i.
But we may vary or modify these arrangements if desirable, so long as we do
not depart from the essential features of this apparatus, namely, the employment
in combination with the mercury of a float or floating weight, acting as above
specified..
In Figures 3 and 4 we have shewn a plan and vertical section, illustrating this
part of our Invention further modified by the employment of a lever k in com-
bination with the said safety valve and morcurial cup or vessel. The said lover has
its fulcrum at k¹, and rests at k³ on a collar or shoulder on the valve spindle c. The
mercurial cup
d is formed with trunnions, whereby it is supported in the fork of
the lever at . The column pipe e in this case extends centrally down through
the annular weight h, which is arranged and acts in combination with the stops i,
as above described.
We may in this modification, when the lever is used, employ the mercurial cup
and column pipe without the floating weight; and we may, if desired, extend the
valve spindle c through or below the lever, and provide the same with a weight, as
in Figure 1.
The second part of our Invention relates to an improved arrangement of the
check valves described in the Specification of our former Letters Patent, dated 30th
December, A.D. 1876, No. 5057.
In this former Specification we have described an inverted check valve, that is to
say, a valve which is closed or pressed against its soat by the upward pressure of a
float in mercury, and a modification in which the valve is pressed on its seat by an
annular weight in mercury, the mercury vessel and float being on the egress side of
the valve.
But, according to our present Invention, we arrange the said cup or vessel below
and on the ingress side of the valve, thereby avoiding the annular construction of
the weight or float, and at the same time so arrange the valve that the excess or
preponderance of the weight or gravity of the float and valve over the buoyancy of
the float in the mercury will tend to close the valve.
This arrangement permits the use of either mercury or of a fluid of less specific
gravity, such as water, for obtaining the elastic support of the valve in the manner
above specified.
This part of our Invention is illustrated in Figures 5, 6, and 7 of the Drawings,
which show valves applicable for the protection of steam boilers, as described in our
said Specification.
Figure 5 is a central longitudinal section of one form or arrangement of our
improved apparatus for giving elastic support to a check valve. The casing lis
formed of cast iron or other suitable metal. The valve m is so placed therein that
it closes by contact of its under side with the valve seat n; is the ingress, and l²,
the egress side of the valve. The said valve is provided with a stem or spindle m¹
projecting from its under side into a vessel or chamber o containing a suitable
quantity of mercury, water, or other liquid, which forms the elastic supporting
medium. At its lower end the said rod or stem has attached to it a float or
plunger p.
And it will be obvious that the weight of this float valve and stem will tend to
close the valve, while at the same time the elastic support afforded by the fluid
will balance or nearly balance and tend to float the valve, and thereby prevent any

page_text: violent movement or impact of the same upon its seat, while allowing it to open
and close freely, so that the automatic and immediate isolation of the boiler would
be effected in case of any accident rendering such isolation necessary.
In Figures 6 and 7 we have shewn a modification of the above apparatus. Either
of the forms of this apparatus may be provided with the ordinary wheel and spindle
used in stop or check valves for pressing the valve upon its seat.
Having thus fully described our said Invention, and the manner of performing
the same, we wish it understood that we claim,-
First. The improved apparatus in which the safety valve is weighted by a cup or
vessel containing mercury arranged in combination with a column pipe and receiver,
and either with or without a lever, and which operates to effect a free discharge of
steam from the boiler, as above set forth.
Second. The modification of this apparatus, wherein we employ a weight floating
in the mercury in combination with suitable stops, and either with or without a
lever, as and for the purpose set forth.
Third. A valve which closes downward, provided with means as above described,
for supporting or partially supporting the same by mercury or other suitable fluid
on the under or ingress side of the valve, in such manner that the said valve will
be balanced or nearly balanced, and any violent impact of the said valve upon its
seat will be prevented.
In witness whereof, I, the said Joseph Hopkinson, for myself and on behalf
of the said John Addy Hopkinson, have hereunto set my hand and seal,
this Eighteenth day of September, in the year of our Lord One thousand
eight hundred and seventy-eight.
JOSEPH HOPKINSON. (L.S.)