Improvements in Pressure Reducing Valves.
Year: 1895

page_text: Date of Application, 12th Feb., 1895-Accepted, 4th May, 1895
COMPLETE SPECIFICATION.
Improvements in Pressure Reducing Valves.
We, EDGAR PRENTICE HOLLY, Mechanical Engineer, of Providence, in the
County of Providence and State of Rhode Island, United States of America,
and HENRY HOWARD and CHARLES TAYLOR HOWARD both of Phenix, Rhode
Island United States of America, Manufacturers do hereby declare the nature of
this invention, and in what manner the same is to be performed, to be particularly
describel and ascertained in and by the following statement :-
Our invention relates to improvements in pressure reducing valves, which are
designed to reduce and maintain an even steam, air or water pressure lower than
the initial pressure. The objects of our improvement, are, first, to produce a
device for reducing pressure from a higher to a lower degree, without the use of
springs, weights or levers, and to accomplish the same without wearing surfaces in
contact.
We attain this object by the mechanism illustrated in the accompanying drawing
in which
Figure 1, is a vertical section of the entire device.
Figure 2, is a top view or plan of the discharge end of the device, showing the
upper guide for the reducing disc.
Figure 3, is a vertical elevation of a portion of the lower guide for the reducing
disc, and
Figure 4, is an elevation of a portion of the reducing disc, and section of its
seat, differing from Figure 1, in that it shows a raised narrow seat.
Similar letters refer to similar parts, throughout the several views.
The housing or case of the device, consists of two chambers A and B, con-
taining the reducing discs C. The lower chamber A, is for the reception of the
high or initial pressure of air, water or steam, through the opening or pipe
connection A'. The steam passes upward through the outlet or passage A into
the upper chamber B. The passage A² is covered by a horizontal circular disc C,
which is considerably larger in diameter than the passage A2, which it covers.
The circular disc C, has a flat lower surface c, corresponding with a flat upper
surface a, of the chamber A. The two surfaces a and c, when no air water or
steam is passing through, would be in contact from the edge of the passage A³, to
the outer edge of the disc C. This disc C, is provided with a centrally projecting
stem or shaft; the portion C', extending above from the upper side of the disc C,
and a portion C³, extending down from the lower side of the disc C. This stem
or shaft C¹, C, is centrally located, and at right angles to the two above mentioned
faces. The upper chamber B, is made large enough to conveniently include the
disc C, and is screwed or bolted to the lower chamber A, at a³.
The central stem C₁ of disc C, extends upward through the guide e³, which is a
bar cast across the outlet B', and bored centrally to receive the end of said stem.
To preserve this vertical movement of the disc correctly, the portion C³, of the
central stem, extends down into the chamber A, and terminates in the upper end of
a vertical stud E, which is located directly under the centre of disc C, and extends
through the bottom of chamber A. The upper end of the stud E, is enlarged
at E¹, for a certain distance, and bored to receive the lower end of the disc stem C²,
which is turned to fit nicely the bored portion e' of stud E, and also grooved or
channelled for water packing, as at e. The upper end of stud E, at E' forms the
guide for the stem C2, and also a small dash pot for disc C. The stud E below E',
A

page_text: is threaded for a short distance at d, fitting..a, correspondingly threaded opening
through hottom of chamber A. Below the portion d, the stud is turned down to
the bottom of the thread and passes through a stuffing box d¹ to the outside of
chamber A, and is either squared at the end, us at d³, or provided with a hand
wheel, by means of which the stud E, may be made to assume a position higher
or lower than shown, by turning stud E, to the right or left, as the screw d will
serve to elevate or depress the whole as desired. As shown, the stud E is at a
low position, leaving a space 2, between the end of stem C2 and bottom of
hole in upper end of stud. With the stud in the position shown, the two faces a
and c, would rest in contact if no air steam or the like were passing through. The
object of the dash-pot guide and grooves in stem C, is to prevent repeated and.
sudden. movement, vertically, of the disc C, or what is called "chattering." As
the space not filled by the stem C2 will be occupied by water which will have to
pass from one groove to another when the disc rises or falls, the time required for
the water to change its position would prevent any very sudden movement of the.
disc. The stem C₁ is enlarged at Cs to a diameter larger than the hole through
the guide bar e³. This is to stop the vertical movement of disc before the stem O²
leaves the end of stud E. In Figure 1, the chambers A and B, are shown in
section, together with a stuffing box. The disc C, is shown in elevation, as is also
the stud E, with the exception of the upper portion E which is shown in section
on line x, x of Figure 3.
Figure 4, is a vertical section of a portion of the lower chamber A with the
disc C in elevation. This is to show the raised seat f. This form of seat is
preferable when the device is to be used for reducing water pressure, and at times,
to be closed tight against said pressure, or where it is used both as a positive valve
and a reducing valve. We shall use both types of seats shown, for steam or water
as conditions require. We have shown the flat seat or surface a, on upper side of
chamber A, depressed somewhat below the surface outside of the diameter of
disc C, and a corresponding bevel on under outer edge of disc. This is not
necessary to the operation; but has a tendency to direct the steam as it passes
out from between the surfaces a and c, in an upward direction. Said bevel may
be any angle, or may be dispensed with entirely.
The operation of the device to reduce pressure, is as follows:
When steam is admitted to the lower chamber A, (through the pipe con-
nections A¹) it will pass as indicated by the arrows, up through the opening or
passage A between the disc C and the upper surface of chamber A, (or between
the surfaces a and c) into the chamber B, and out through the discharge B¹. We
proportion the two areas for any terminal pressure we wish to maintain from a
known initial. Suppose the device, as shown, with a steam pressure of 50 lbs. per
square inch in the chamber A, would allow 5 lbs. per square inch in chamber B,
and that the device is reducing the pressure for a steam heating system, and from
the shutting off a portion of the radiation, the terminal pressure should raise to
5-1 lbs. This increases the pressure on the upper side of disc 9 of one pound,
which would move the disc nearer the top of chamber A, or reduce the space
between the surfaces a and c, thereby reducing the quantity of steam passing.
between said surfaces, thus causing the pressure in the system to fall at once to
5 lbs., when the disc C, would remain in a balanced position between the initial and
terminal pressures; but held in its position by the terminal pressure. If, from
using more radiation requiring a greater quantity of steam, the terminal pressure
should fall to 4-9 lbs. per square inch, then there would be a reduction of weight
on the upper face of disc C, amounting to 9 of one pound. The initial pressure
immediately has a slight advantage over the terminal, and moves the disc a little
farther from the seat or surface, thereby increasing slightly, the distance between a
and c.
As soon as a sufficiently greater quantity of steam has filled the system
beyond chamber B, and raised the pressure to 5 lbs., the disc would remain
balanced in the position that would allow this greater quantity of steam to
maintain the required pressure, the disc C, always automatically adjusting itself

page_text: vertically, to the terminal pressure, to allow the necessary opening between a and c,
that will furnish the quantity necessary to, maintain the terminal 5 lbs. In speaking
of 5 lbs., we mean- 5 lbs. above atmospheric pressure, and we only use the amount
stated, for illustration, as we may have any terminal pressure required. We make
the proportioned area A and C, for any lowest pressure.we may require. Should
we wish to increase the terminal pressure above said lowest pressure, we increase
positively, the space between a and c, by screwing the stud E, higher into the
chamber B, to such an elevation that the bottom c' of the recess c', will touch the
lower end of disc stem C¹. A still greater elevation of the stud E, would
increase the distance between a. and c, and permit, say 6 lbs. terminal pressure.
still greater elevation of the stud E, would increase the distance between a and c,
and permit 7 lbs. terminal pressure, and so on, by increasing positively the distance
between a and c, we increase the terminal pressure proportionately.
A
If the initial pressure should be increased 10 lbs. the terminal would only receive
one-tenth of the increase, or then, if necessary, we would lower slightly the stud E,
and adjust for 5lbs., and so in a reverse order.
In operation, there are no parts in contact, except the guide portions of disc C,
and consequently the device will not be affected to destroy its accuracy, by any
wearing that may occur by use, as is the case in similar devices where the valve is
of the slide or piston type. Our device will operate just as perfectly, if reversed,
allowing the discharge end B, to be below the disc, or in other words, upside
down. In that position, we should place a light coil spring or its equivalent,
between the guide bar es and disc C, simply to overcome the weight of disc, so
that when steam should be shut off entirely, the disc would not fall out of the
controlling influence of the terminal pressure.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1st. In a pressure reducing valve, the following instrumentalities: A supply
chamber and a distributing chamber, a passage connecting said chambers, a disc
larger than said passage to cover it, and an adjustable stud entering into the initial
pressure chamber to raise or lower said disc, substantially as set forth.
2nd. In a pressure reducing valve, the combination of an initial pressure
chamber, a receiving chamber, of lower pressure a passage connecting said
chambers, a disc larger than the passage, to cover it, stems projecting from both
faces of the disc with guides fast to the chambers, arranged to guide the stems, and
an adjustable stud entering into the initial pressure chamber to raise or lower said
disc by the stem on its under side, substantially as described.
3rd. In a pressure reducing valve, the combination of the chambers A and B,
with passage A³, a disc as C having a central shaft or stem C', C³, to guide said
disc in a vertical movement, a guide e, in the chamber B, a stud E, receiving in
one end of itself a portion of the stem C³, said portion having a series of annular
grooves made around it to form a piston packing to prevent sudden vibrations of the
disc, said stud E provided with a screw d, fitting a threaded opening through
chamber A, and a stuffing box d', and follower d', substantially as described.
4th. In a pressure reducing valve, the combination of the chambers A and B,
passage A, between said chambers, dise C, covering the passage A2, a centrally
projecting stem on said disc in chamber B with a position guide therefor formed in
said chamber B, a centrally projecting stem on said disc in chamber A, a stud E,
constructed to receive a portion of said latter stem to raise the disc from the
passage and increase the pressure in the chamber B, substantially as described.
5th. In a pressure reducing valve, the combination of the chambers A and B,
dise C, having a central shaft or stem C1, C2, C, being enlarged at c³, to a
diameter larger than the opening in guide e³, thereby forming a stop of the vertical
movement of disc C, and adjusting stud E, substantially as described.

page_text: 6th. In a pressure reducing valve, the combination of the chambers A and B, a
passage A, to the chamber A, a disc C provided with stems C', C³ covering said
passage A, and of a considerably larger diameter than said passage, and guided
in its vertical motion by the guide bar e, and stud E, a raised seat surrounding
said passage A, all substantially as shown and described for the purpose as set
forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.