IMPROVEMENTS IN STEAM GENERATORS, AND IN SAFETY VALVES FOR STEAM GENERATORS, APPLICABLE IN PART IN THE CONSTRUCTION OF VALVES FOR WATER AND OTHER FLUIDS
Year: 1877

page_text: LETTERS PATENT to James Blake, of Manchester, in the County of Lancaster,
Boiler Maker, for the Invention of "IMPROVEMENTS IN STEAM GENERATORS,
AND IN SAFETY VALVES FOR STEAM GENERATORS, APPLICABLE IN PART IN THE
CONSTRUCTION OF VALVES FOR WATER AND OTHER FLUIDS."
Sealed the 7th Tunn 7070
PROVISIONAL SPECIFICATION left by the said James Blake at the Office
of the Commissioners of Patents on the 8th December 1877.
JAMES BLAKE, of Manchester, in the County of Lancaster, Boiler Maker.
"IMPROVEMENTS IN STEAM GENERATORS, AND IN SAFETY VALVES FOR STEAM
GENERATORS, APPLICABLE IN PART IN THE CONSTRUCTION OF VALVES FOR WATER
AND OTHER FLUIDS."
My Invention relates in the first place to the class of steam generators known as
sectional boilers, that is to say, to boilers composed of a number of similar parts
connected together, and consists in the employment in each section of two or more
globular chambers connected together.
When carrying this part of my Invention into effect I form globular chambers
composed of boiler plate, or of steel or wrought-iron plates, the said chambers being
by preference sufficiently large to admit of being entered for examination, cleaning,
and repairs.
In one arrangement I employ two such chambers connected together by means
of one water tube or pipe for each of the sections at the furnace end of the generator,
the said water tube passing through the fire-grate or between the two parts of the
fire-grate. Each of the remaining sections consists of three globular chambers,
connected together by means of cylindrical necks or junction pieces, which I prefer
to make large enough to permit of the passage of a man from one chamber to the
other. The upper chambers are each formed with a man-hole, and connected by
means of junction pipes with a steam reservoir.
The lower chambers are connected by means of junction pipes with a range of

page_text: piping, through which the sediment and water may be discharged, and into which
the feed water may be admitted. As many of the sections thus formed may be
connected together as may be necessary to furnish the required supply of steam.
Two, or more than three, of the globular chambers may be connected together to
form one section.
In lieu of connecting the chambers in certain of the sections by means of single
water tubes they may be connected by means of clusters of water tubes or of
conical or parallel water pipes, or of clusters of such tubes and pipes, and such
sections may be entirely used in the formation of the steam generator, or may be
used otherwise than at the furnace end thereof.
In the cases of large generators a number of sections may be arranged together
in cross rows, each row consisting of two or more sections connected together and
to the other rows.
In some cases I may depart from the globular form, especially when clusters of
tubes are employed as aforesaid.
My Invention relates in the second place principally to safety valves for steam
generators, but is also applicable in the construction of valves for controlling or
permitting the flow of water and other fluids.
In ordinary safety valves the valve only opens to a comparatively small extent
when the limit of pressure is reached, and as a consequence the excessive pressure
is not reduced so quickly as is considered to be advisable. To remedy this defect
is the object of my Invention.
In my improved safety valve the valve is formed on or is connected with a piston
which is fitted to slide or to move within a shell or cylinder. The said piston is
of larger diameter than the said valve, and is an easy fit within the said cylinder,
there being sufficient clearance to avoid the likelihood of the piston sticking in the
cylinder. The said cylinder is connected with a comparatively small supplementary
valve, which is loaded to the blowing-off weight.
For convenience the said supplementary valve may have an area of one inch.
The spindle of this valve is extended through an opening bored in the end of the
said piston. The steam has access to the upper or outer sido of the piston through
the space between the piston and the cylinder, and also through the said opening,
which is a little larger in diameter than the said spindle. The lower or inner end
of the said spindle is provided or formed with a valve, which when the aforesaid
auxilliary valve is raised closes or restricts the passage for steam through the
opening through which the said spindle passes. The distance between the two
valves on the said spindle is by preference capable of adjustment. The outer
supplementary valve may be fitted to screw upon the said spindle so as to be
adjustable thereon; or the adjustment may be otherwise effected:.
When the auxilliary valve is raised by the steam pressure the passage through
the piston is closed or restricted as aforesaid, and at the same time the pressure of
steam above or on the outside of the piston becomes reduced by the escape from
the auxilliary valve. The pressure of steam on the inner side of the piston now
forces it upwards or outwards, whereby the main escape valve is opened. When
the piston is forced outwards it is caused to bear against a shoulder within the
said cylinder, the consequence being that the passage for the flow of steam hetween
the piston and the cylinder is closed or restricted, and the steam flowing to the
auxilliary valve has to pass principally or entirely through the central passage in
the piston. The result is that the main escape valve is opened wide, thus
furnishing means for the rapid escape of the excess of steam.
Although I have styled a part of my apparatus a piston it must not be under-
stood that any packing is required, nor that such piston is of necessity circular or
cylindrical in form, although I consider the form of a hollow cylinder having
openings to admit steam to the interior to be very suitable.
In one form of the apparatus I form the said piston with a flanch, which rests
upon a seating when the escape valve is closed; or I otherwise arrange that the
said piston shall act as a valve to close the passage for the flow of steam through
-

page_text: the space between the said piston and the inside of the cylinder in which it moves.
In this case I do not form the main escape valve in one piece with the piston, but
arrange that when the piston moves upwards or outwards the said valve is
opened.
When employed for water or other fluids I provide suitable means for opening
and closing the supplementary valve by hand, the pressure of the water or fluid
acting upon the piston to open the main valve, as in the case of the safety valve;
or in some cases the action of the said supplementary valve may be controlled by
means of a float or other equivalent appliance.
O SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Blake in the Great Seal Patent Office on the 8th June
1878.
JAMES BLAKE, of Manchester, in the County of Lancaster, Boiler Maker.
"IMPROVEMENTS IN STEAM GENERATORS, AND IN SAFETY VALVES FOR STEAM
GENERATORS, APPLICABLE IN PART IN THE CONSTRUCTION OF VALVES FOR WATER
AND OTHER FLUIDS."
My Invention relates principally to safety valves for steam generators, but is
also applicable in the construction of valves for other steam apparatus and for
water heaters.
In ordinary safety valves, the valve only opens to a comparatively small extent
when the limit of pressure is reached, and as a consequence the excessive pressuro
is not reduced so quickly as is considered to be advisable. To remedy this defect
is the object of my Invention.
In my improved safety valve, the valve is formed on or is connected with a
piston, which is fitted to slide or to move within a shell or cylinder. The said
piston is of larger diameter than the said valve, and is an easy fit within the said
cylinder, there being sufficient clearance to avoid the likelihood of the piston sticking
in the cylinder. The said cylinder is connected with a comparatively small
auxilliary valve which is loaded to the blowing-off weight. The steam has access
to the upper or outer side of the piston, through the space between the piston and
the cylinder, and also through an opening through which passes the spindle of the
auxilliary valve. The lower or inner end of the said spindle is provided or formed
with a valve, which when the aforesaid auxilliary valve is raised, closes or restricts
the passage for steam through the opening through which the said spindle passes.
The distance between the two valves on the said spindle is by preference capable of
adjustment. The auxilliary valve may be fitted to screw upon the said spindle so
as to be adjustable thereon, or the adjustment may be otherwise effected. When
the auxilliary valve is raised by the steam pressure, the pressure of steam above or
on the outside of the piston becomes reduced by the escape from the auxilliary
valve. The pressure of steam on the under side of the piston now forces it upwards
or outwards, whereby the main escape valve is opened.

page_text: And in order that my Invention may be readily described and understood, I have
appended hereunto a Sheet of Drawings marked with letters of reference and
illustrative of arrangements which may be adopted when carrying my Invention
into effect. Referring in this place to the said Drawings,—
Fig. 1 represents a vertical section of a safety valve suitable for employment in
connection with a steam generator. In the said Fig. A is the body or outer shell
of the valvo. This body may be made of cast iron, as is usual, or of any other
suitable metal, and is formed with a branch or pipe b for connection with the
steam generator, and with a branch o for connection with the blow-off pipe through
which the escaping steam is discharged, but of course the valve can be used without
such blow-off pipe. Within the said body is fixed a seating, upon which rests the
main escape valve D. This valve is formed in one piece with a hollow cylindrical
piston E, which is arranged to slide or move within a cylindrical shell which is
cast or formed upon a bonnet or cover g. Upon this cover is also formed a tubular
pillar h. The upper or outer end of this pillar forms a seating for the small
auxilliary valve I, which is secured to a casting or part j suitably formed to carry
dead weights as in other descriptions of safety valves, such for example as the
"Cowburn's" valves.
For convenience of representation the pillar h and the part are broken; but it
will be understood that the dimensions of the parts are made suitable to the load
which the valve is to carry. For convenience, I prefer to arrange for the valve I
to have an area equal to-one square inch, but the area may be less or more than
this. The outer end of a spindle K is screwed into the valve I, and on the inner
end of this spindle is formed or fixed a valve l, which is provided with a seating m
which is screwed into the piston e, in order that the said valve may be got into
position within the said piston. The steam has access through openings to the
interior of the piston, and through the spaces between the seating m and the
spindle, and between the piston and the shell f. The piston is made an easy fit
within the said shell, so that it can move freely to and fro within it, without a
tendency to stick fast, at the same time that the clearance between the piston and
the shell must not permit such n flow of steam to the space N as will maintain the
high pressure within the said space when the valve I is slightly opened by an excess
of pressure. The spindle K is so adjusted within the valve I by means of the
screwed part of the said spindle, as that when the said valve is raised from its
seating by an excess of pressure the valve closes or greatly restricts the passage
for the flow of steam through the scating m. During ordinary periods when the
valve I is closed, the steam has access to the interior of the piston and to the space
N, so that the pressure is about the same within the said space as in the passage b,
and therefore the main valve is firmly held against its seating. On the pressure
rising sufficiently to open the auxilliary valve I steam escapes from the space N.
As the valve is now closed or nearly closed, steam can obtain access only or
principally through the clearance between the piston and the shell to the space N,
the consequence being that the pressure within the said space falls below the
pressure in the passage b. As the area of the piston E is greater than the area of
the escape passage of the main valve, the said piston will now be forced upwards
or outwards, supposing the clearance between the piston and the shell ƒ not to be
too great as herein-before indicated. The main valve being now open, a free
passage for the discharge of a large body of steam is provided.
When the piston moves upwards or outwards it bears against a shoulder o
formed by a contraction of the bore of the shell f, whereby the passage for the 5
flow of steam through the aforesaid clearance is closed or greatly restricted in order
that the main valve may be sustained in its open position. When the valve I
closes, the pressure within the space N is restored by the flow of steam through m,
and the main valve is caused to close. I prefer to make the piston E and the valve
seatings and shell of gun metal or of a suitable metal which will not oxidise as in
the case of cast iron, and in some cases the body A may be made of the same metal
as the piston and other indicated parts, in which case the shell ƒ may be dispensed

page_text: with, and the said body be bored to suit the piston, a seating o being formed on the
inside of the cover.
Although I have used the term piston it must not be understood that any
packing is necessarily required, although a packed piston might be used if the
tendency to stick could be obviated, nor is it absolutely necessary that the piston
must be cylindrical, although I consider that form to be the best.
Fig. 2 illustrates a modification which may be made in the arrangement. In
this example the piston is formed with two flanches p and q, the latter being formed
by the projecting edge of a piston cover or end which is screwed or secured to the
piston after it has been got into position within its cylinder. When the main valve is
closed the flanch q rests upon one end of the cylindrical seating within which the
piston slides or moves, and thus prevents or restricts the flow of steam through the
clearance between the piston and the said seating, and when the piston is forced
outwards to open the main valve the flanch p bears against the other end of the said
seating.
The arrangement may be varied by causing one of the flanches, say, for example,
the flanch p, to bear against one or the other of two seatings. The modification
enables me to make the piston an easier fit within its seating or shell, and thereby
to lessen the tendency of the piston to stick therein.
The main valve D is not formed in one piece with the piston, but is connected
with it in such a manner as to permit the piston to have a little independent move-
ment, as clearly indicated in the Drawing, in order that the tight closing of the
valve and of the flanch on the piston upon its seating may be ensured.
Fig 3 illustrates a further modification in the arrangement, Fig. 4 repre-
senting a cross section on the line, in Fig. 3. In this example the valve lis
mounted within a seating formed in the main body on one side of the seating or
cylinder in which the piston slides instead of being mounted within the said piston
as in the former examples. The auxilliary valve is connected with the valve 7 by
means of a screwed shank which permits the passage at 1 to be adjusted The
valve D is formed with an internal passage, at the upper or outer end of which is
seated a valve r, which is formed on or fixed to the piston. In the example it is
screwed in the end of the piston. The piston is fitted to slide easily upon the
valve D to an extent which is limited by a shoulder on the said valve. When
the valve I opens and the piston slides upwards or outwards, the valve is
opened, whereby steam is permitted to escape from the space N through perfora-
tions & into the discharge passage, and the pressure within the said space is thereby
reduced sufficiently to enable the piston to open the main valve. As the valve r
in the example is smaller than the main valve it is opened with a lesser reduction
of pressure within the space N, and as when open it effects a greater reduction of
pressure than could be obtained by the opening of the auxilliary valve alone,
greater power for opening the main valve is obtained than in the case of the valve
illustrated by Fig. 1. In both examples when the valve I closes the valve 7 by re-
admitting steam to the space N causes the main valve to close. The valve I may
be larger or smaller in proportion than as represented.
8
In my Provisional Specification I described a form of steam generator, and I also
mentioned that my improved safety-valve might be adapted to be employed in the
construction of valves for water and other fluids, but since the filing of the said
Provisional Specification I have discovered that the steam generator described as
aforesaid was not so novel as I considered it to be at the time, and I therefore have
not included it herein nor in the Drawings, and I make no claim in respect of it,
and also with a view to render my claims more definite and distinct I have not
included any adaptation of my Invention to valves for regulating the flow of water
or fluids, and I therefore make no claim for such adaptation excepting when my
valves are used as safety valves, and I would have it to be understood that what I
do claim is,
Furst. The safety valves constructed and acting, substantially as set forth and
indicated herein-before and in the accompanying Drawings.

page_text: Secondly. The employment of a supplementary or auxilliary valve loaded to the
maximum pressure to reduce the pressure upon one side of a piston which effects
the opening of a main escape valve, substantially as set forth and indicated.
And, lastly. The combination of the valves I and 7, the piston E, and the main
valve D, arranged and acting substantially as and for the purposes set forth and
indicated.
In witness whereof, I, the said James Blake, have hereunto set my hand
and seal, this Seventh day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.
Signed and sealed by the said
James Blake in the presence of
HUGH GRANT,
Clerk to Edward K. Dutton,
Agent to the Patentee,
St. Ann's Churchyard,
Manchester.
JAMES BLAKE. (L.S.)