Pilot-operated modulating valve system and flow stabilizer incorporated therein

Claim 2

A pilot-operated modulating valve system, which comprises: a main valve adapted to open and close in response to flow of fluid into and out of an operating chamber therein, a pilot valve adapted to open and close in response to fluid pressure conditions on at least one side of said main valve, conduit means to connect said pilot valve to the upstream and downstream sides of said main valve, said conduit means having a restrictor therein between said pilot valve and said upstream side of said main valve, second conduit means, one side of said second conduit means being connected to said operating chamber, the other side of said second conduit means being connected to said first-mentioned conduit means at a point between said restrictor and said pilot valve, and flow stabilizing and regulating means provided in said second conduit means to restrict greatly the flow of fluid in both directions therethrough at all times except when a pressure at said one side of said main valve changes rapidly to either a substantial amount above a predetermined pressure or a substantial amount below said predetermined pressure, said flow-stabilizing and regulating means including valve means automatically operable to reduce the degree of constriction in said second conduit means when said pressure at said one side of said main valve increases rapidly to at least said substantial amount above said predetermined pressure or decreases rapidly to at least said substantial amount below said predetermined pressure.

Claim 3

The invention as claimed in claim 1, in which said substantial amount is on the order of at least 1 p.s.i.

Claim 4

The invention as claimed in claim 1, in which said valve means included in said flow-stabilizing and regulating means is adapted to open and thereby reduce said degree of constriction in said second conduit means when the pressure differential across said flow stabilizing and regulating means is on the order of at least 1 p.s.i.

Claim 5

The invention as claimed in claim 1, in which said valve means included in said flow stabilizing and regulating means comprises first and second regulating and check valves which are in parallel to each other and are reverse oriented relative to each other.

Claim 6

The invention as claimed in claim 4, in which said flow-stabilizing and regulating means further comprises means to define a highly restricted flow passage extending between the opposite sides of said flow stabilizing and regulating means, said restricted flow passage being in parallel with both of said first and second regulating and check valves whereby fluid may always flow in either direction through said restrictEd flow passage.

Claim 7

The invention as claimed in claim 1, in which said flow-stabilizing and regulating means comprises a valve housing having a flow passage therethrough, a check plate formed across said flow passage and having a first port therethrough, a poppet seated on one side of said check plate to close said first port, a first spring seated on said poppet to bias the same toward seated position but to permit shifting thereof to open said first port, second port means extending through said check plate, valve head means seated on the other side of said check plate over said second port means to close the same, and a second spring seated on said valve head means to bias the same toward seated position but to permit shifting thereof to open said second port means.

Claim 8

The invention as claimed in claim 6, in which said poppet has a restricted flow passage therethrough to permit continuous flow of fluid in either direction through said first port.

Claim 9

The invention as claimed in claim 7, in which said first and second springs are sufficiently strong that the pressure differential across said first port required to unseat said poppet is a substantial number of pounds per square inch, and the pressure differential across said second port means required to unseat said valve head means is a substantial number of pounds per square inch.

Claim 10

A pilot-operated pressure-reducing valve system, which comprises: a main valve adapted to open and close in response to flow of fluid into and out of an operating chamber therein, the inlet of said main valve being connected to a source of fluid under relatively high pressure, the outlet of said main valve being connected to supply fluid at a predetermined substantially lower pressure, a pilot valve adapted to open and close in response to the fluid pressure on the downstream side of said main valve, conduit means to connect said pilot valve to the upstream and downstream sides of said main valve, said conduit means having a restrictor therein between said pilot valve and said upstream side of said main valve, second conduit means, one side of said second conduit means being connected to said operating chamber, the other side of said second conduit means being connected to said first-mentioned conduit means at a point between said restrictor and said pilot valve, and flow stabilizing and regulating means provided in said second conduit means to restrict greatly the flow of fluid in both directions therethrough at all times except when the pressure at said downstream side of said main valve changes rapidly to either a substantial amount above a predetermined pressure or a substantial amount below said predetermined pressure, said flow-stabilizing and regulating means including valve means automatically operable to reduce greatly the degree of constriction in said second conduit means when said pressure at said downstream side of said main valve increases rapidly to at least said substantial amount above said predetermined pressure or decreases rapidly to at least said substantial amount below said predetermined pressure.

Claim 11

A pilot-operated pressure-reducing valve system, which comprises: a main valve adapted to open and close in response to flow of fluid into and out of an operating chamber therein, the inlet of said main valve being connected to a source of fluid under relatively high pressure, the outlet of said main valve being connected to supply fluid at a predetermined substantially lower pressure, a pilot valve adapted to open and close in response to the fluid pressure on the downstream side of said main valve, conduit means to connect said pilot valve to the upstream and downstream sides of said main valve, said conduit means having a restrictor therein between said pilot valve and said upstream side of said main valve, second conduit means, one side of said second conduit means being connected to said operating chamber, the other side of said second conduit means being connected to said first-mentioned conduit means at a point between said restrictor and said pilot valve, and flow stabilizing and regulating means provided in said second conduit means to restrict greatly the flow of fluid in both directions therethrough at all times except when the pressure at said downstream side of said main valve changes rapidly to either a substantial amount above a predetermined pressure or a substantial amount below said predetermined pressure, said flow-stabilizing and regulating means including valve means automatically operable to reduce greatly the degree of constriction in said second conduit means when said pressure at said downstream side of said main valve increases rapidly to at least said substantial amount above said predetermined pressure or decreases rapidly to at least said substantial amount below said predetermined pressure.

Claim 12

The invention as claimed in claim 9, in which said substantial amount is on the order of at least several p.s.i.

Claim 13

The invention as claimed in claim 9, in which said valve means included in said flow stabilizing and regulating means is adapted to open and thereby reduce said degree of constriction in said second conduit means when the pressure differential across said flow stabilizing and regulating means is on the order of at least several p.s.i.

Claim 14

The invention as claimed in claim 9, in which said valve means included in said flow stabilizing and regulating means comprises first and second regulating and check valves which are in parallel to each other and are reverse oriented relative to each other.

Claim 15

The invention as claimed in claim 12, in which said flow-stabilizing and regulating means further comprises means to define a highly restrictEd flow passage extending between the inlet and outlet sides of said flow stabilizing and regulating means, said restricted flow passage being in parallel with both of said first and second regulating and check valves whereby fluid may always flow in either direction through said restricted flow passage.

Claim 16

The invention as claimed in claim 9, in which said flow-stabilizing and regulating means comprises a valve housing having a flow passage therethrough, a check plate formed across said flow passage and having a first port therethrough, a poppet seated on one side of said check plate to close said first port, a first spring seated on said poppet to bias the same toward seated position but to permit shifting thereof to open said first port, second port means extending through said check plate, valve head means seated on the other side of said check plate over said second port means to close the same, and a second spring seated on said valve head means to bias the same toward seated position but to permit shifting thereof to open said second port means.

Claim 17

The invention as claimed in claim 14, in which said poppet has a restricted flow passage therethrough to permit continuous flow of fluid through said first port, said restricted flow passage having a wire loosely mounted therein.

Claim 18

The invention as claimed in claim 14, in which said poppet is seated on the side of said check plate remote from said operating chamber, and in which said valve head means is seated on the side of said check plate adjacent said operating chamber.

Claim 19

The invention as claimed in claim 16, in which said poppet has a throttling portion extending into said first port, said throttling portion tapering convergently in a direction toward said operating chamber.

Claim 20

The invention as claimed in claim 9, in which said main valve is adapted to close in response to flow of fluid into said operating chamber, and to open in response to flow of fluid out of said operating chamber.

Claim 21

A modulating valve combination, which comprises: a main valve adapted to control the flow of a liquid, said main valve incorporating operating means adapted when liquid is injected therein to effect shifting of said main valve toward one position, and when liquid is drained therefrom to effect shifting of said main valve toward the opposite position, means responsive to a liquid pressure on at least one side of said main valve to inject liquid through a conduit means into said operating means when said liquid pressure is on one side of a predetermined set point, and to drain liquid through said conduit means from said operating means when said liquid pressure is on the opposite side of such set point, and flow-stabilizing and regulating means provided in said conduit means to restrict greatly the rate of flow of liquid therethrough both into and out of said operating means when the liquid pressure on said one side of said main valve is near said predetermined set point, said flow stabilizing and regulating means being adapted automatically when said liquid pressure is a substantial amount above said predetermined set point to increase greatly the rate of flow of liquid in one direction through said conduit means, said flow-stabilizing and regulating means being adapted automatically when said liquid pressure is a substantial amount below said predetermined set point to increase greatly the rate of flow of liquid in the opposite direction through said conduit means.

Claim 22

A modulating valve combination, which comprises: a main valve adapted to control the flow of a liquid, said main valve incorporating operating means adapted when liquid is injected therein to effect shifting of said main valve toward one position, and when liquid is drained therefrom to effect shifting of said main valve toward the opposite position, means responsive to a liquid pressure on at least one side of said main valve to inject liquid through a conduit means into said operating means when said liquid pressure is on one side of a predetermined set point, and to drain liquid through said conduit means from said operating means when said liquid pressure is on the opposite side of such set point, and flow-stabilizing and regulating means provided in said conduit means to restrict greatly the rate of flow of liquid therethrough both into and out of said operating means when the liquid pressure on said one side of said main valve is near said predetermined set point, said flow stabilizing and regulating means being adapted automatically when said liquid pressure is a substantial amount above said predetermined set point to increase greatly the rate of flow of liquid in one direction through said conduit means, said flow-stabilizing and regulating means being adapted automatically when said liquid pressure is a substantial amount below said predetermined set point to increase greatly the rate of flow of liquid in the opposite direction through said conduit means.

Claim 23

The invention as claimed in claim 19, in which said main valve is connected as a pressure-reducing valve, in which said one side of said main valve is the downstream side thereof, in which said main valve is adapted to close in response to injection of liquid into said operating means and to open in response to drainage of liquid out of said operating means, in which said one side of said predetermined set point is a pressure above that of said set point, and in which said opposite side of said predetermiNed set point is a pressure below that of said set point.