IMPROVEMENTS IN VALVES
Year: 1876

page_text: LETTERS PATENT to Robert Chapman-Anderson, of Wood Green, in the County
of Middlesex, Civil Engineer, for the Invention of "IMPROVEMENTS IN
VALVES."
Sealed the 5th December 1876, and dated the 6th September 1876.
PROVISIONAL SPECIFICATION left by the said Robert Chapman Anderson
at the Office of the Commissioners of Patents on the 6th September 1876.
ROBERT CHAPMAN ANDERSON, of Wood Green, in the County of Middlesex,
Civil Engineer. “IMPROVEMENTS IN VALVES"
The object of my Invention of improvements in valves is to reduce at will to
any desired extent the pressure of water, steam, air, or gases in pipes or other
conduits, while maintaining at that reduced pressure a constant flow of the liquid
or fluid in the pipes. This object is effected by means of weights applied in such
a manner that the amount by which the pressure is reduced is directly proportional
to the weight applied, and so long as that particular weight is left undisturbed the
pressure will remain unaltered irrespective of variations either in the pressure of
the supply or in the quantity of liquid or fluid drawn off; and should the dis-
charge at any time be reduced to nil the valve will be closed entirely, and thus
prevent any inci case in the reduced pressure.
In carrying out my Invention I fit an air-tight piston into the upper portion of a
vertical tube, which is open at both ends, and I connect the piston by means of a
rod with a valve of the same area in cross section, and by which the lower end of
the tube may be closed. This 1od projects a short distance above the piston,
and terminates in a flat disc fixed horizontally for the purpose of supporting
weights.
The inlet pipe is connected to the vertical tube at a point about midway between
the piston and valve, so that whatever pressure is conveyed by the inlet it is com-
municated equally to piston and valve, and the two forces being in opposite
directions, and equal to one another (the area of piston and valve being identical),
the valve is always maintained in a state of equilibrium, no matter how great or
how small the pressure conveyed by the inlet.
The lower end of the vertical tube is inserted into an air-tight chamber from

page_text: which the outlet proceeds, and in such manner as to allow of the valve opening to
its fullest extent without coming in contact with the bottom or sides of the
chamber. Now, if the equilibrium be destroyed by placing weights upon the disc
at the upper end of the piston rod, the piston and valve will descend together, the
liquid or fluid will flow through the valve opening into the chamber, and this.
opening will continue to increase in area as the valve descends until the pressure,
which will gradually accumulate in the chamber, exerts an upward force on the
valve equal to the downward force exerted by the weight on the disc, when equil-
brium will be again restored. Should the outlet opening be now increased the
pressure in the chamber will be diminished, and the upward force against the
valve being less than the downward force of the weight on the disc the valve will
descend until its area of opening is large enough to restore the former pressure,
when there is again equilibrium. Should the outlet be now closed entirely the
prossure in the chamber will increase, and the upward force against the valve being
greater than the downward force of the weight on the disc the valve will be
forced upwards until it is closed entirely; for so long as the valve is open, be it
ever so little, the fluid which escapes will exert an upward pressure until it closes
the valve. The pressure in the chamber, which is always the same as that of the
outlet, is thus regulated at pleasure by the number of the weights placed upon the
disc; thus if the area of valve be 1 square inch, and it be desired to maintain a
pressure at the outlet of 40 lbs. on the square inch, the weight which must be
placed upon the disc to produce this pressure will be 40 lbs.
A valve constructed as above described may be adapted for use with steam, water,
aar, or gas, the principle of construction remaining the same, though the details will
depend upon the object for which it is desired to use the valve.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Chapman Anderson in the Great Seal Patent Office on the
6th March 1877.
ROBERT CHAPMAN ANDERSON, of Wood Green, in the County of Middlesex,
Civil Engineer. "IMPROVEMENTS IN VALVES"
The object of my Invention of improvements in valves is to reduce at will to
any desired extent the pressure of water, steam, air, or gases in pipes or other
conduits, whilst maintaining at that reduced pressure a constant flow of the liquid
or fluid in the pipes This object is effected by a peculiar construction of valve in
which weights are applied in such a manner that the reduced pressure is in direct
proportion to the weight applied; and so long as that particular weight is left
undisturbed the pressure will remain unaltered n respective of variations either in
the pressure of the supply or in the quantity of liquid or fluid drawn off; and
should the discharge at any time be reduced to nil the will be closed entirely, and
will thus prevent any increase in the reduced pressure.
In the accompanying Drawing I have illustrated in Diagrams X and Z the
principle on which my valves are constructed, the remaining Figures being various
views of details of construction in adapting my principle to valves for regulating
the pressure of water, steam, or gas, and which will be more fully referred to
hereafter.
The same letters of reference refer to corresponding parts in all the Figures and
the diagrams.
In carrying out my Invention I fit an air-tight piston a, diagrams X and Z, into
the upper portion of a vertical tube or cylinder b, which is open at both ends, and
I connect the piston a by means of a rod c with a piston valve & of the same
superficial area as the piston a. By this valve d the lower end of the tube b is
closed. This rod c projects a short distance above the piston a, and carries a disc o
fixed horizontally for the purpose of supporting weights ƒ.

page_text: The inlet pipe g is connected to the vertical tube or cylinder b at a point about
midway between the piston a and valve d, so that whatever pressure is conveyed
by the inlet is communicated to the piston and valve, and when the valve d
entirely closes the lower end of the tube the pressure upwards against the piston (
is exactly counterbalanced by the downward pressure against the valved (the area of
piston and valve being the same), there is therefore an equilibrium of pressure.
Now, if the equilibrium be destroyed by placing a weight upon the disc c, the
piston a and valve d will descend together until the pressure on the valve dis
relieved by an amount equivalent to that exerted by the weight f on the disc.
The piston a and valve a will then cease to descend, and equilibrium will be
restored; for whilst the downward pressure on the valve is lessened the upward
pressure on the piston a remains practically the same as at first, there will therefore
be a resultant force upwards against the piston equal to the difference between
these two opposite forces, that is to say, equal to the weight f; but as this upward
force is exactly counterbalanced by the equal downward force of the weight on the
dise the piston a, valve d, and weight fare in equilibrium, and the force of the
liquid or fluid thus allowed to escape through the openings h, h, will be in proportion
to the weight f
It having now been shewn that the escaping force or reduced pressure is always
according to the weight applied on the disc e, and does not depend on the pressure
in the inlet, it follows that so long as any particular weight is applied to the disc
and left undisturbed, so long will the reduced pressure or escaping force remain
unaltered irrespective of variations in the pressure of the inlet
The above description and the diagrams X, Z, represent fairly the general
features of my Invention, subject to various modifications dependent upon the use
to which I desire to adapt it, as will be described hereafter; but the principle above
stated is strictly the same in all.
In illustrating this principle of action, which renders my valve a truly correct
and efficient automatic regulator and reducer of pressure, I have neither taken into
consideration the effects of friction on the piston and valve nor of the weight of
the piston, valve, spindle, and disc
In diagram X I have illustrated my Invention as adapted for use where a con-
stant fixed quantity of liquid or fluid has to be discharged continuously within a
given time, as for instance, where water is to be discharged from a large tank or
storage reservoir direct into open basins, tanks, or conduits for the supply of
towns, or for the purposes of irrigation. By the use of this apparatus, when once
the measured flow of the apparatus is known, the quantity discharged from the
reservoir in any given period is also known; such discharge can at any time be
altered at pleasure by increasing or decreasing the weight fon the disc e.
In Figures 1, 2, and 3 I have shown the valve apparatus when applied as a regu-
lator for steam, compressed air, water under pressure, or when vapouis, gases, or
liquids are used as agents for obtaining motive power. In this case the apparatus
is attached in the usual way to the inlet and exit pipes, the former communicating
with the generator or reservoir of force, and the latter with the engine or other motor,
the speed of which is to be regulated. Instead of using the disc e loaded with
weights f, which for bigh pressure would be almost impossible, I employ a pair of
levers p, p, Figures 3 and 4, mounted in juxtaposition to one another, and having their
fulcrums on standards q, q, fixed to the top of the apparatus In place of the disce,
Figures 4 and 5, and in the diagrams X and Z, the top of the piston rod b is pro-
vided with a pair of grooved rollers or bowls 7, 7, on one of which near their
respective fulcrums rests one of the levers p The outer ends of these levers p
support one end of a curved or arched bar 8, to the ends of which weights f are
attached. The ends of the curved or arched bar are forked, and carry small grooved
rollers or bowls t, t, which roll on the outer ends of the levers p, which may be
bevelled off on both sides to fit into the groove of the rollers t, t, the object of this
arrangement being that the vertical pressure on the top of the piston rod b should
be always the same during the entire stroke of the piston (which would be the case

page_text: if a loaded disc were used as in Figures 4 and 5), for if the levers p be loaded in
the usual way by attaching weights direct thereto the pressure on the piston rod
would vary according to the position of the lever, the greatest loverage or pressure
occurring when the levers are in a horizontal position; but by the present arrange-
ment the same pressure is maintained at all angles by reason of the horizontal
distance between the fulcrum of the lever and the weight being always the
same.
If desired the piston rod b may be connected to and made to work a throttle
valve in the exit pipe by means of a rack and pinion, as shewn at Figures 1, 2,
and 3, or in any other convenient manner.
20
Figures 4, 5, and 6, and diagram Z represont in sectional and side elevation, and
in a plan view partly in section, a form of apparatus in which the liquid or fluid
instead of being discharged direct into an open basin or tank is received into an air-
tight chamber i, from which an exit pipe conducts it to any place where it is
required. The use of this chamber i is merely to act as a receiver for the discharged
fluid, and to permit of the exit pipe / being led off in any desired direction. Now
so long as the discharging capacity of the exit pipe is equal to or greater than
that of the valve openings h, h, and there be no obstruction to the fluid flowing
ficely away, the effect will be the same as if the fluid were discharged direct into
the open tanks or busins, as in diagram X, but if a tap or stop valve be placed at
any point on the exit pipe, whereby its discharging capacity becomes less than that
of the valve openings h, h, pressure gradually accumulates in the exit pipe k until
that degree of pressure is reached which is the equivalent of that exerted by the
weight f. Up to this point the piston a and valvo d. will remain in equilibrium,
but any increase in this pressure will be prevented by its destroying the equi-
librium between the piston, the valve, and the weight f, the effect of which would
be to cause the piston and valve to ascend together until the discharging capacity
of the valve openings h, h, become equivalent to that of the tap or valve in the
exit pipe, that is to say, until the pressure in the exit pipe k has resumed its former
state. Thus any pressure in the exit pipe k beyond what is due to the weight f, f,
is prevented and the discharging capacity of the valve openings h, h, and of the tap
or valve in the exit pipe are always alike within the limits of such discharge,
and should the tap or valve be turned so as to prevent all discharge from the exit
pipe, then the piston a and valve & will ascend automatically and prevent all dis-
charge into the exit pipe. Thus at all times and under all circustances (independent
of the variations of pressure in the inlet) the reduced pressure will be maintained
in the exit pipe within the limits of the flow, and cannot be exceeded be the limit
what it may.
This form of apparatus lis especially adapted to reducing the pressure.in the
subsidiary mains and pipes for supplying water to towns, as by its means the
leakage and other damage or loss due to excessive pressure is thereby prevented, and
an efficient regulator is furnished.
Figure 7 is a vertical section and Fig. 8 a horizontal section shewing the valve
apparatus as applied to reduce the pressure of gas in the mains or pipes forming
the gas supply to towns. In this case the maximum pressure to be reduced is so
very small that the united weight of the piston and valve is greater in itself than
would be supported by the pressure, so that instead of a disc for loading the valve
apparatus, with weights as in the former instances the upper extremity of the valve
spindle or rod c is connected to one end of a cord or chain, which passes over a
pulley, the other end being secured to a light box m, which is intended to receive
weights If this box m be loaded so as to exactly counterbalance the weight of the
piston a and valve this would be equivalent to having a weightless piston and
valve surmounted by a weightless disc with the weight of the other arrangement
removed, and its effect would be the same, viz, that when gas under pressure is
admitted into the inlet g the valve d would rise and close the passage entirely, and
thus prevent any pressure from existing in the outlet, for the reduced pressure
allowed by the valve to the outlet pipe being always in direct proportion to the

page_text: weight applied, it follows that when that weight is nil then the reduced pressure is
also nul Whatever portion of the counterbalance weights m be removed it would
therefore be the same as if that portion were placed on a disc, and the reduced
pressure in the exit pipe would then be in direct proportion to that portion of thic
weight which is removed.
In the apparatus shewn at Figures 7 and 8 the piston a and valve d are constructed
somewhat differently to those already described, in consequence of the difference in
the nature of the service for which the apparatus is intended. The piston a is
formed of an inverted cylindrical air-tight vessel like a gasometer, which is let down
into a trough n filled with mercury. The valve & consists of a circular disc, and
carries an annular trough o, which is also filled with mercury This trough is
intended to fit round the outer opening h when the piston a and valve & are raised,
and by means of the mercury the outlet or opening will be hermetically sealed
and the gas prevented from passing into the pipes.
In each case a cover may be applied to the top of the cylinder b in order to
prevent dirt from falling on to the piston a, but air holes must be provided, either
in the cover or made in the sides of the cylinder above the piston.
In the case of the water valve the cover may be air tight, and the space above
the piston may be opened to the atmosphere through a small pipe connected with
the inlet g, and provided about midway, with a two-way cock, which is normally
open to the air, so that in case of emergency water from the inlet may be allowed
to flow on to the top of the piston so as to act as an extra weight, and thus open
the valve to its utmost extent in order that a greater pressure of water may be
obtained for use.
Having now described my Invention of "Improvements in Valves," and having
explained the mannor of carrying the same into effect, I wish it to be understood
that under the above in part recited Letters Patent I do not wish to limit myself
to the exact details of construction herein described, but what I claim is, con-
structing valves for regulating the pressure in pipes or conduits for water, steam,
air, gas, or other liquids or fluids, with a piston and valve connected rigidly
together, as herein set forth, and so placed with regard to the inlet pipe that the
pressure of the inlet flow shall be exerted on the piston and valve in opposite
directions, as and for the purpose herein shown and described
In witness whereof, I, the said Robert Chapman Anderson, have horeunto set
my hand and seal, the Second day of March, in the year of our Lord One
thousand eight hundred and seventy-seven.
R. CANDERSON. (L.S.)