IMPROVEMENTS IN SAFETY VALVES AND APPARATUS FOR STEAM GENERATORS."
Year: 1880

page_text: LETTERS PATENT to Sam Hallam, of Manchester, in the County of Lancaster,
Engineer, for an Invention of "IMPROVEMENTS IN SAFETY VALVES AND
APPARATUS FOR STEAM GENERATORS."
PROVISIONAL SPECIFICATION left by the said Sam Hallam at the Office
of the Commissioners of Patents on the 3rd November 1880.
SAM HALLAM, of Manchester, in the County of Lancaster, Engineer. "IMPROVE-
MENTS IN SAFETY VALVES AND APPARATUS FOR STEAM GENERATORS."
My Invention relates in the first place to the safety valves of steam generators.
My improved safety valve is made with a double seating, which is surrounded by a
flanch or wall. The valve proper rests upon a loose scating which rests upon the
ordinary seating. When the valvo opens the steam escapes through the space
between the valve and seating and the said wall. In the formation which I now
consider to be suitable the said loose seating is formed with a "vee" edge and
with through passages for steam. The said seating is fitted to slide upon a central
pin, and a projecting part of the upper valve is fitted to slide in the said seating.
A collar or head upon the said pin limits the lift of the said seating. The said
upper valve is loaded by any ordinary or suitable means. A second part of my
Invention relates to apparatus for lifting or easing the load upon the said valve or
upon a safety valve otherwise formed at times when the water falls to a
dangerously low level. A weighted lever is arranged to raise the load upon the
valve when the weight upon the said lever preponderates. The said weight is
counterbalanced by means of a hollow globe or a chamber which under ordinary
conditions is full or nearly full of water. The said chamber communicates with
the interior of the boiler by means of two pipes or tubes. One pipe, say, for sake
of distinction, the shorter pipe, extends within the boiler to the low-water level, the
other or longer pipe extending below the said level; the shorter pipe communicates
with the upper part of the chamber, and the longer pipe with the lower part
thereof. When by reason of the lowering of the water level the steam passes
through the shorter pipe into the chamber, the water is displaced and the weight
on the lever preponderates and effects the opening of the safety valve. In a
suitable arrangement the said lever is forked and rests upon fulcra on each side of
the safety valve pillar. Arms provided with bowls act upon the lower side of
the weight ring of the valve when the weight upon the lever preponderates. The
said globe or chamber is provided with trunnions which rest in seatings upon the
lever, and the connecting pipes or tubes are suitably curved to enable them to yield
to the movements of the chamber.

page_text: Died
SPECIFICATION in pursuance of the conditions of the Letters Patent
by the said Sam Hallam in the Great Seal Patent Office on the 3rd May
1881,
SAM HALLAM, of Manchester, in the County of Lancaster, Engineer. "IMPROVE-
MENTS IN SAFETY AND OTHER VALVES AND APPARATUS FOR STEAM GENERATORS,
APPLICABLE IN PART TO OTHER USES."
My Invention relates in the first place to the safety valves of steam generators.
My improved safety valve is made with a double seating which is surrounded by a
flunch or wall. The valve proper rests upon a loose seating which rests upon the
ordinary seating. When the valve opens the steam escapes through the space
between the valve and seating and the said wall. A second part of my Invention
relates to apparatus for lifting or easing the load upon the said valve or upon a
safety valve otherwise formed at times when the water falls to a dangerously low
level. A weighted lever is arranged to raise the load upon the valve when the
weight upon the said lever preponderates. The said weight is counterbalanced by
means of a hollow globe or chamber, which under ordinary conditions is full or
nearly full of water. The said chamber communicates with the interior of the
boiler by means of two pipes or tubes. One pipe, say, for sake of distinction, the
shorter pipe, extends within the boiler to the low-water level, the other or longer
pipe extending below the said level. The shorter pipe communicates with the
upper part of the chamber, and the longer pipe with the lower part thereof. When
by reason of the lowering of the water level the steam passes through the shorter
pipe into the chamber, the water is displaced and the weight on the lever
preponderates and effects the opening of the safety valve.
And in order that my Invention may be fully understood I will refer to a Sheet
of Drawings which I have attached hereunto and which are illustrative of my
improvements. In tho said Drawings Fig. 1, which is drawn about the full size of
the example selected for illustration, represents a vertical section of a dead weight
safety valve constructed in accordance with my Invention. In the said Fig. a is a
stand pipe which is fixed to the generator in the ordinary or in any suitable
manner. In the upper end of this pipe is fixed a seating b which takes the place
of the seating in the ordinary safety valve. The fixed seating b is cast or formed
with a cross bar b', which carries a central pin c, which is screwed into an
enlargement of the central part of the said cross bar, and the said seating
is also cast or formed with a flanch or wall 6. Upon the said fixed scating is
mounted a loose seating d, which in the example is formed with a vee-edge,
and upon this loose seating is mounted the valve e, which sustains the outer
shell which is loaded with weights in the ordinary manner, a rounded pin g
in the said shell resting in a hollow formed in the said valve. Fig. 14 represents a
plan of the loose seating, wherein it will be seen that it is formed with radial ribs d¹,
which are united to a central boss which is bored to slide upon the pin c. The
upper edges of these ribs are extended upwards above the said central boss into a
cupped recess in the underside of the valve, and the inner vertical edges of the
extensions of the said ribs are bored to receive a boss e¹, which is forined upon the
valve c.
It will be seen that the wall 62 extends above the loose seating, and
surrounds and encloses the same, leaving a narrow annular passage for the escape
of steam in an upward direction. When the valve is lifted by the pressure of tho
steam the loose seating is also raised, the amount of its lift being limited by a head
which is formed upon the pin c. When the valve is opened steam is permitted to
escape between the fixed seating and the loose seating, and also between the latter
and the valve, and I have found that the wall be has the effect of causing the valve
to be lifted higher than would be the case if the said wall were absent from the

page_text: apparatus, and the practical efficiency of the valve is thereby increased. Fig. 2
illustrates the application of this part of my Invention to a lever safety valve, and
also indicates a inodification which may be made in the formation of the valve and
seatings. In this example a wing piece h, formed with wings which are turned on
their outer edges to slide within the bored seating b, is secured to the valve e,
which is provided with a screw which enters a tapped hole which is formed in a
boss at the junction of the said wings. The outer edges of the upper ends of the
sail wings are turned to receive the loose seating d, which is in the form of a
ring, which is bored to slide upon the said wings. A weighted lever i, of an
ordinary or suitable form, is substituted for the loaded shell f. The action of the
valve is the same as in the case of the example first described. The details of the
apparatus may be otherwise greatly varied so long as the loose seating and the outer
wall are retained, and also the loose seating may be varied in form.
The second part of my Invention is illustrated by Fig. 3, wherein represents
the load of a dead weight safety valve, which may be constructed in accordanco
with Fig. 1, or be of any ordinary or suitable construction. Upon each side of the
stand pipe of the valve is fixed or formed a stud m, and the two studs constitute
the fulcra of a lever n, which is forked for some distance from one end, each
member of the fork resting upon one of the said studs or fulcra. Between the
outer ends of the members of the fork is mounted a hollow globe or chamber o,
which is provided with trunnions which rest in seatings in the two ends of the
fork. The said chamber is connected by means of two pipes ? and with
the steam generator, the said pipes being curved in the manner indicated in the
Drawings, or in any suitable manner, in order that they may yield to the move-
ments of the chamber, but, if preferred for any reason, stuffing boxes or union
joints may be employed in connection between one part of each pipe and another,
so as to permit of the movement of the said chamber. The pipe p communicates
with a pipe which extends within the chamber nearly to the top thereof, as
indicated by the dotted lines, and also communicates with a pipe which extends
within the steam generator to the determined low-water level.
The pipe "
establishes a communication between the bottom of the chamber and the water
space of the generator, and extends to a suitable extent below the low water level,
so that its lower end shall not be uncovered during the working of the generator.
The forked part of the lever n is formed with two arins n', which are provided
with bowls or wheels which bear against the underside of the flanch upon the
shell, upon which the load rests, and the end of the lever which is not forked is
provided with a weight &. The chamber o is filled with water, and during the
ordinary working of the generator the water cannot escape so long as the ends of
both of the pipes p and within the generator are under water, but in the event
of the water level sinking until the lower end of the pipe p becomes exposed the
steam has access through the said pipe into the chamber and displaces the water
therein, which runs through the pipe into the generator. So long as the
chamber remained filled with water it would overbalance the weight 8, as
indicated in the Drawing, but when the water has been replaced by steam the
weight & will preponderate and will cause the lever to turn upon its fulcra in the
direction which will cause the bowls upon the arms n¹ to exert an upward pressure
upon the flanch of the safety valve shell, and, supposing the parts to be suitably
proportioned, the said pressure will be sufficient to raise the load with the assistance
of the ordinary working steam pressure. The apparatus may be adapted to any
description of safety valve, and the manner in which the lever acts upon the load
may be varied to suit the description of valve to which the apparatus is to be
applied.
?"
Having now fully set forth and indicated the nature of iny said Invention, and
the manner in which I carry the same into practical effect, I would have it to be
understood that I claim,—
First. The safety valves, constructed substantially as set forth and indicated
hereinbefore, and in and by Figs. 1, 1ª, and 2 of the accompanying Drawings.

page_text: Secondly. The valve resting upon a loose seating, which in turn rests upon a a
fixed seating and the surrounding wall; leaving a comparatively narrow annular
space for the upward escape of steam, substantially as set forth and indicated.
Thirdly. The apparatus applied to a safety valve, substantially as set forth and
indicated hereinbefore, and by Fig. 3 of the accompanying Drawings.
And, lastly. The hollow chamber to contain water, mounted upon a lever and
connected with the interior of a steam generator by means of pipes so as to ensure
the discharge of water from the chamber on the water in the generator falling to
the low water level, substantially as and for the purpose set forth and indicated.
In witness whereof, I, the said Sain Hallam, have hereunto set my hand
and seal, this Second day of May, in the year of our Lord One thousand
eight hundred and eighty one.
Signed, sealed, and delivered in
the presence of
EDWARD K. DUTTON,
41, John Dalton St.,
Manchester.
(Agent for the Patentec.)
SAM HALLAM. (L.S.)