Year: 1886

page_text: Date of Application, 12th Oct., 1886.
Complete Left, 12th July, 1887.
Complete Accepted, 12th Aug., 1887.
We FREDERICK FOSTER of Niagara Works Eagle Wharf Road Hoxton London in
the County of Middlesex Engineer and HENRY MOY THOMAS of No. 4 Canonbury
Place London in the County of Middlesex Engineer do hereby declare the nature of
this invention to be as follows:-
This invention relates to that class of pressure reducing valves which are capable of
receiving a supply of air or gases under pressure and of delivering a supply of the
same at any determined lower pressure capable of regulation.
The accompanying sectional drawings will assist in describing the nature of this
invention and the construction and working of the pressure reducing valve which are
as follows:-
In Fig. 1A is a chamber formed of two parts bolted or screwed together at the
flanges shown. B is the inlet capable of being connected by means of its screwed
part with the source of supply of air or gases under pressure.
is the valve
controlling the inlet and suspended upon a spindle D which is itself suspended from a
corrugated metallic diaphragm E. F is a hollowed nut which secures the spindle D
to the metallic diaphragm E and forms a guide for the block G. H is a small valve
through which the gas or air may pass from the space beneath to the space above the
diaphragmn E. J is a spindle with screw thread working through a gland nut K and
fitted with a handle or hand wheel L. M is an outlet from the chamber A above the
diaphragm E.
In the outlet M a balanced valve similar to a safety valve (not shown) must be
fitted to complete the apparatus and though not absolutely necessary it may be
convenient to attach a dial pressure indicator also. In that case the safety valve and
the dial pressure indicator (not shown) may be put in a "tee" piece and the "tee"
piece screwed into the outlet M. N is the outlet through which the supply of air or
gases at the reduced pressure is taken. P is a stop preventing the valve C from

page_text: descending beyond a certain limit in order to avoid damaging the elasticity of the
corrugated diaphragm E. The area of the passage through the safety valve should
greatly exceed the area of the passage through the valve H.
The working is as follows:-
To set the reducing valve in action screw down the spindle J gently by means of
the hand wheel. The spindle J (which can revolve freely in the block G when
required) brings the block G in contact with the spindle D and depressing this together
with the corrugated diaphragm E it causes the valve C to retire from its seating as
shown and a supply of compressed air or gas from the source enters the chamber A.
The outlet N being closed the only outlet from the lower part of the chamber A is by
way of the passage Q past the valve H which lifts more or less as shown and feeds the
upper part of the chamber until a pressure is reached at which the safety valve (not
shown) at M has been set to lift; the balance weight or the spring (by means of
which the safety valve is loaded) being capable of adjustment for varying pressures in
the usual way. Then unscrew the spindle J.
At this stage the pressure reducing valve is ready for acting automatically.
Directly the outlet at N is opened the pressure in the chainber below the diaphgram E
falls in proportion as the gas or air is withdrawn; the valve H immediately closes
preventing the passage of gas or air from above the diaphragm E to establish an
equilibrium, the pressure above the diaphragm exceeds the pressure below and as soon
as the excess of pressure above becomes great enough to drive the valve C from its
seating the pressure in the lower part of the chamber A is restored and the apparatus
continues to deliver gas or air at the desired pressure. If the desired pressure is
exceeded, the valve H is opened, the pressure above the diaphragm E increases until
the safety valve lifts and the upper part of the diaphragm loosing the portion of the
casing to react upon, represented by the area of the opening effected by the raising of
the safety valve; the air or gas passes through the valve C faster than it can pass
through the valve H, the equilibrium is for the time disturbed and the valve C closes
to its seating and remains there until the pressure beneath the diaphragm E is again
diminished, then the valve C again leaves its seating and so on automatically.
The above arrangement is all that is necessary for dealing with a reduced pressure
bearing some reasonable proportion to the high pressure retained by the storage vessel
from which the supply is derived but when the ratio of the pressure at the source of
supply to the pressure required, is great then it is more convenient to couple two
pressure reducing valves attaching the inlet of the second to the outlet of the first and
setting them at different pressures so as to reduce the pressure by stages.
Fig. 2 shows such an arrangement carried to the extreme to deliver at a pressure
slightly above atmospheric pressure or even to feed a pump at a pressure below
atmospheric pressure.
It represents the lower part of Fig. 1 the corrugated diaphragham E being exposed
on one side to the atmosphere and the spindle D being solid instead of being fitted
with a valve.
The tension of the corrugated diaphragm E is arranged to take the weight of the
spindle D when required to deliver at very low pressure and weights S. S¹ S" are
to be added as required for pressures above atmospheric pressure.
The block, G (Fig. 1) may be fitted at its upper part with an elastic seating such
as vulcanised india rubber as shown at T and an abutment U so that when the
spindle J is unscrewed an air tight joint is made independently of the packing in
the gland.
When the pressure reducing valve is allowed to stand for a length of time in
readiness for working as required, if any leakage takes place from that part of the
chamber A above the corrugated diaphragm E the valve H will lift and restore the
equilibrium within the chamber A above and below the corrugated diaphragm E and
provided the pressure is not reduced beyond the point at which sufficient pressure is
retained to drive the valve C from its seating the pressure reducing valve will work
and as soon as the valve is driven from its seating the normal pressure in the upper
part of the chamber A above the corrugated diaphragm E will be restored & the

page_text: pressure reducing valve will work at a pressure determined by the extent to which
the safety valve has been loaded.
It is obvious that the air spring or cushion represented by the compressed air above
the corrugated diaphragm E (Fig. 1) may be admitted through any separate conduit
from the source of supply. We have described what we consider to be the most
suitable means and the arrangement herein described and illustrated offers advantages
regarding the automatic working which a separate conduit for the required pressure
would not command.
Improvements in Pressure Reducing Valves.
We FREDERICK FOSTER of Niagara Works Eagle Wharf Road Hoxton in the
County of Middlesex Engineer and HENRY MOY THOMAS of No. 4 Canonbury Place
London in the County of Middlesex Engineer do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to that class of pressure reducing valves which are capable of
receiving a supply of air or gases under pressure and of delivering a supply of the
same at any determined lower pressure capable of regulation.
The accompanying sectional drawings and the drawings accompanying our
provisional specification will assist in describing the nature of this invention and the
manner in which the same is to be performed.
In Fig. 1. A is a chamber formed of two parts bolted or screwed together at the
flanges shown. B is the inlet capable of being connected by means of its screwed part
with the source of supply of air or gases under pressure is the valve controlling the
inlet and suspended upon a spindle D which is itself suspended from a corrugated
metallic diaphragm E. F is a hollowed nut which secures the spindle D to the
metallic diaphragm E and forms a guide for the block G. H is a small valve through
which the gas or air may pass from the space beneath to the space above the
diaphragm E. J is a spindle with screw thread working through a gland nut K and
fitted with a handle or hand wheel L. M is an outlet from the chamber A above the
diaphragm E. In the outlet M a balanced valve similar to a safety valve (not shown)
must be fitted to complete the apparatus and though not absolutely necessary it may
be convenient to attach a dial pressure indicator also.
In that case the safety valve and the dial pressure indicator (not shown) may be
put in a "tee" piece and the "tee" piece screwed into the outlet M. N is the outlet
through which the supply of air or gases at the reduced pressure is taken.
stop preventing the valve C from descending beyond a certain limit in order to avoid
P is a

page_text: The area of the passage
damaging the elasticity of the corrugated diaphragm E.
through the safety valve should greatly exceed the area of the passage through the
valve H.
By this arrangement there is a leakage from the chamber A below the diaphragm E
into the space above the diaphragm E gradually increasing the pressure above until
that pressure is reached at which the safety valve is lifted. This relieves the pressure
above the diaphragm E but the passage Q with the valve H fitted therein does not
afford sufficient vent to materially reduce the pressure below the diaphragm E which
is consequently raised closing the valve C.
In order to reduce the amount of loss by this leakage and make the operation of 1
the safety valve take place at longer intervals the passage Q may be constructed as
shown at Fig. 3 with a double valve seat and double ended valve 1 instead of the
single ended valve H herein before described and instead of the stop P for limiting
the deflection of the diaphragm E a platform extending from the double valve seating
is arrested in its descent by the depending arms 2, 21 211 which come in contact with
the lower interior part of the compartment A and affords such a complete support for
the diaphragm E that a much more sensitive plate may be employed with this
arrangement than by the arrangement herein before described employing only the stop P
for arresting the descent of the diaphragm E.
When employing a very sensitive diaphragm with the support 2, 21 21 a fixed
perforated support should be provided to limit the deflection of the diaphragm in the
upward direction. This perforated support may be fixed in any convenient manner in
the upper part of the compartment A above the diaphragm E.
The operation of a reducing valve as above described is as follows:
To set the reducing valve in action screw down the spindle J gently by means of
the hand wheel L. The spindle J (which can revolve freely in the block G when
required) brings the block G in contact with the spindle D and depressing this
together with the corrugated diaphragm E it causes the valve C to retire from its
seating as shown and a supply of compressed air or gas from the source of supply
enters the chamber A. The outlet N being closed the only outlet from the lower part
of the chamber A is by way of the passage Q past the valve H which lifts more or less
as shown and feeds the upper part of the chamber A until a pressure is reached at
which the safety valve (not shown) at M has been set to lift. When the double ended
valve 1 is employed instead of the valve H the cavity in the block G is to be such as
to prevent the lower valve of the double ended valve 1 reaching its seating while the
spindle J remains depressed.
Directly the pressure escapes at the safety valve the spindle J should be unscrewed
raising the block G in the guide formed by the hollow nut F and allowing an
equilibrium to be established in the whole of the chamber A both above and below
the diaphragm E. Any surplus gas or air below the diaphragm E passes through the
valve H until such equilibrium is established at a pressure below that at which the
safety valve (not shown) at M has been set to lift, the balance weight or the spring by
means of which the safety valve is loaded being capable of adjustment for varying
pressures in the usual way. At this stage the pressure reducing valve is ready for
acting automatically.
Directly the outlet at N is opened the pressure in the chamber A below the
diaphragm E falls in proportion as the gas or air is withdrawn; the valve H imme-
diately closes preventing the passage of gas or air from above the diaphragm E to
establish an equilibrium. The pressure above the diaphragm exceeds the pressure
below and as soon as the excess of pressure above becomes great enough to drive the
valve C from its seating the pressure in the lower part of the chamber A is restored
and the apparatus continues to deliver gas or air at the desired pressure. If the
desired pressure is exceeded the valve H is opened, the pressure above the diaphragm E
increases until the safety valve lifts and the upper part of the diaphragm losing the
portion of the casing to react upon, represented by the area of the opening effected by
the raising of the safety valve; the air or gas passes through the valve faster than
it can pass through the valve H the equilibrium is for the time disturbed and the

page_text: valve C closes to its seating and remains there until the pressure beneath the
liaphragm E is again diminished, then the valve C again leaves its seating and so on
automatically.
The block G (Fig. 1) may be fitted at its upper part with an elastic seating such as
vulcanised india rubber as shown at T and an abutinent U so that when the spindle J
is unscrewed an air tight joint is made independently of the packing in the gland.
When the pressure reducing valve is allowed to stand for a length of time in
readiness for working as required; if any leakage takes place from that part of the
chamber A above the corrugated diaphragm E the valve H will lift and restore the
equilibrium within the chamber A above and below the corrugated diaphragm E and
provided the pressure is not reduced beyond the point at which sufficient pressure is
retained to drive the valve from its seating the pressure reducing valve will work
and as soon as the valve C is driven from its seating the normal pressure in the upper
part of the chamber A above the corrugated diaphragm E will be restored and the
pressure reducing valve will work at a pressure determined by the extent to which the
safety valve has been loaded.
When it is necessary to keep a reducing valve always in readiness for immediate
action the air cushion may conveniently be supplied to the chamber A above the
diaphragm E from the high pressure store admitting the gas or air by a jamb valve 3
shown in Fig. 4 which being closed shuts off all exterior communication with the part
of the chamber A above the diaphragm.
The diaphragm in this case is not to be fitted with any valve but hermetically
separates the upper and lower portions of the chamber A so as to provide for the
instantaneous action of the reducing valve after long standing inoperative, there being
no possibility of leakage.
Such a reducing valve may be made to work within a very close range of pressure
that is to say that the pressure at which the valve delivers when working and the
pressure at which it closes or shuts off may be made to approach the same point very
closely without unduly increasing the area of the diaphragm in proportion to the area
of the controlling valve, but by increasing the sensitiveness of the diaphragm.
Such a result is attained by the arrangement shown in Fig. 4 in which 4 is a
perforated support for arresting the movement of an india rubber diaphragm 5 in an
upward direction and 6 is a plate with guides or guide band 7 fitting freely in the
lower part of the chamber A leading the plate 6 into a position in which its further
descent is arrested by the sides of the chamber A thus forming a support for the
india rubber diaphragm 5 in a downward direction.
Below the valve seating for the valve C is a guide for the valve stem, with a
spring 8 by which in its normal position, before admitting the air cushion above the
diaphragm the valve C is brought to its seating and the plate 6 with the india rubber
diaphragm are partly lifted. The plate 6 is detached from the stem of the valve C
upon which it rests freely so as to allow the diaphragm to rise a short distance after
the valve C has reached its seating. The hereinbefore described arrangements are all
that are necessary for dealing with a reduced pressure bearing some reasonable
proportion to the high pressure retained by the storage vessel from which the supply
is derived but when the ratio of the pressure at the source of supply, to the pressure
required is great then it is more convenient to couple two pressure reducing valves
together attaching the inlet of the second to the outlet of the first and setting them at
different pressures so as to reduce the pressure by stages. Fig. 2 shows such an
arrangement carried to the extreme to deliver at a pressure slightly above atmospheric
pressure or even to feed below the piston of a pump at a pressure below atmospheric
pressure.
It (Fig. 2) represents the lower part of Fig. 1 the corrugated diaphragm E being
exposed on one side to the atmosphere and the spindle D being solid instead of
being fitted with a valve. The tension of the corrugated diaphragm E is arranged to
take the weight of the spindle D when required to deliver at very low pressure and
weights S. Š¹ 8" are to be added as required for pressures above atmospheric
pressure.

page_text: Instead of employing the weights S. S₁ S" the reducing valve may be fitted with
a bridge piece extending over the diaphragm E with a set screw and coiled spring
bearing at the centre of the diaphragm and by regulating the set screw any required
pressure may be applied to the diaphragm without employing the weights S. S'S".
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
1. A reducing valve having a single valve H or double ended valve 1 forming a
communication between the spaces below and above the diaphragm with spindle J for
driving the main valve C from its seating when required substantially as hereinbefore
described and illustrated by Figs. 1 and 3.
2. The employment of a spring or weight regulating valve commonly called a safety
valve in combination with a diaphragm having a valve through which air or gases are
admitted to form the necessary air cushion above the diaphragm substantially as
hereinbefore described.
3. A reducing valve employing an air cushion above the diaphragm derived from
the source of supply of air or gases at high pressure either periodically as illustrated
by Fig. 4 or automatically as illustrated by Fig. 1 substantially as herein before
described.
4. The combination of two reducing valves the outlet of the first communicating
with the inlet of the second for dealing with a great range of pressure between the
high pressure source and the low pressure supply required substantially as described
and illustrated by Figs. 1 or 4 and Fig. 2.