# US 2019/0316696 A1 · Damped check valve having multi-pressure operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0316696 A1 - Document ID: US20190316696A1 - Status: Published application - Kind: A1 - Application number: 15/951,991 - Filed: 2018-04-12 - Published: 2019-10-17 - Earliest claimed: 2018-04-12 - Assignees: Woodward, Inc. - Inventors: Jimroy Arner McCormack - Web page: https://patentgrep.com/patent/US20190316696A1 ## CPC - F02C 7/22: Fuel supply systems - F16K 17/025: {and remaining open after return of the normal pressure} - F16K 1/54: Arrangements for modifying the way in which the rate of flow varies during the actuation of the valve - F16K 15/065: {spring pulling the closure member against the seat} - F16K 17/0413: {in the form of closure plates} - G05D 7/014: {using sliding elements} - Y10T 137/7925: Piston-type valves - Y10T 137/7929: Spring coaxial with valve - Y10T 137/7932: Valve stem extends through fixed spring abutment - Y10T 137/7933: Yoke or cage-type support for valve stem - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A damped check valve having multi-pressure operation is provided. The check valve includes a liner with a poppet movable within the liner. The liner defines a flow passage aligned along a longitudinal axis defined by the liner. A biasing element is operably coupled between the poppet and the liner to bias a first flow face of the poppet against an annular seat. The first flow face is configured such that a first fluid pressure is required to move the poppet from the closed position to an open position wherein the poppet is unseated from the annular seat and a second fluid pressure is required to hold the poppet in the open position, the second pressure being less than the first pressure. There is a sufficient diametrical clearance between the poppet and the liner which allows for flow control at pressures which are less than the initial opening pressure. ## Claims ### Claim 1 A check valve, comprising: a liner, the liner defining a flow passage aligned along a longitudinal axis defined by the liner; a poppet, the poppet having a first flow face and a second flow face; a biasing element operably coupled between the poppet and the liner to bias the first flow face against an annular seat defined by the liner in a closed position; and wherein the first flow face is configured such that a first fluid pressure is required to move the poppet from the closed position to an open position wherein the poppet is unseated from the annular seat and a second fluid pressure is required to hold the poppet in the open position, the second pressure being less than the first pressure. ### Claim 2 (depends on 1) The check valve of claim 1, wherein a first portion having a first area of the first flow face is arranged such that fluid will contact said first portion in the closed position, and wherein a second portion of the first flow face having a second area greater than the first area is arranged such that fluid will contact said second portion when the poppet is unseated from the annular seat in an open position. ### Claim 3 (depends on 1) The check valve of claim 1, wherein the flow passage has an inlet portion and an outlet portion downstream from the inlet portion relative to a direction of the flow of fluid through the flow passage, and wherein an axially extending sidewall of the poppet is interposed between the first and second flow faces. ### Claim 4 (depends on 3) The check valve of claim 3, wherein the poppet is movable from the closed position to an open position wherein the poppet is unseated from the annular seat and from the open position to a full open position, wherein in the full open position an entirety of the axially extending sidewall is downstream relative to the direction of fluid flow through the flow passage from a downstream edge of the outlet portion. ### Claim 5 (depends on 4) The check valve of claim 4, wherein a radial clearance is formed between the axially extending sidewall and the outlet portion of the flow passage such that a leakage flow is permitted from the inlet portion through the outlet portion in the open position. ### Claim 6 (depends on 1) The check valve of claim 1, further comprising a seal, the seal situated in the poppet such that a portion of the seal is exposed on the first flow face. ### Claim 7 A check valve, comprising: a liner, the liner defining a flow passage aligned along a longitudinal axis defined by the liner; a poppet, the poppet having a first flow face and a second flow face; a biasing element operably coupled between the poppet and the liner to bias the first flow face against an annular seat defined by the liner in a closed position; and wherein a first portion having a first area of the first flow face is arranged such that fluid will contact said first portion in the closed position, and wherein a second portion of the first flow face having a second area greater than the first area is arranged such that fluid will contact said second portion when the poppet is unseated from the annular seat in an open position. ### Claim 8 (depends on 7) The check valve of claim 7, wherein the first flow face is configured such that a first fluid pressure is required to move the poppet from the closed position to an open position wherein the poppet is unseated from the annular seat and a second fluid pressure is required to hold the poppet in the open position, the second pressure being less than the first pressure. ### Claim 9 (depends on 7) The check valve of claim 7, wherein the flow passage has an inlet portion and an outlet portion downstream from the inlet portion relative to a direction of the flow of fluid through the flow passage, and wherein an axially extending sidewall of the poppet is interposed between the first and second flow faces. ### Claim 10 (depends on 9) The check valve of claim 9, wherein the poppet is movable from the closed position to an open position wherein the poppet is unseated from the annular seat and from the open position to a full open position, wherein the in the full open position an entirety of the axially extending sidewall is downstream relative to the direction of fluid flow through the flow passage from a downstream edge of the outlet portion. ### Claim 11 (depends on 10) The check valve of claim 10, wherein a radial clearance is formed between the axially extending sidewall and the outlet portion of the flow passage such that a leakage flow is permitted from the inlet portion through the outlet portion in the open position. ### Claim 12 (depends on 7) The check valve of claim 7, further comprising a retainer affixed to the poppet, the biasing element trapped between the retainer and the liner. ### Claim 13 (depends on 7) The check valve of claim 7, wherein a plurality of inlet ports are formed through the liner such that fluid surrounding an exterior of the liner is in communication with the flow passage via the plurality of inlet ports. ### Claim 14 (depends on 9) The check valve of claim 9, wherein the inlet portion of the flow passage has a first diameter and the outlet portion of the flow passage has a second diameter greater than the first diameter. ### Claim 15 A check valve, comprising: a liner, the liner defining a flow passage aligned along a longitudinal axis defined by the liner, the flow passage having an inlet portion and an outlet portion downstream from the inlet portion relative to the direction of the flow of fluid through the flow passage; a poppet, the poppet having a first flow face and a second flow face, wherein an axially extending sidewall of the poppet is interposed between the first and second flow faces; a biasing element operably coupled between the poppet and the liner to bias the first flow face against an annular seat defined by the liner in a closed position of the check valve; wherein the poppet is movable from the closed position to an open position wherein the poppet is unseated from the annular seat and from the open position to a full open position, wherein the in the full open position an entirety of the axially extending sidewall is downstream relative to the direction of fluid flow through the flow passage from a downstream edge of the outlet portion; and wherein a radial clearance is formed between the axially extending sidewall and the outlet portion of the flow passage such that a leakage flow is permitted from the inlet portion through the outlet portion in the open position. ### Claim 16 (depends on 15) The check valve of claim 15, wherein the first flow face is configured such that a first fluid pressure is required to move the poppet from the closed position to an open position wherein the poppet is unseated from the annular seat and a second fluid pressure is required to hold the poppet in the open position, the second pressure being less than the first pressure. ### Claim 17 (depends on 15) The check valve of claim 15, wherein a first portion having a first area of the first flow face is arranged such that fluid will contact said first portion in the closed position, and wherein a second portion having a second area greater than the first area is arranged such that fluid will contact said second portion when the poppet is unseated from the annular seat in the open position. ### Claim 18 (depends on 15) The check valve of claim 15, wherein a portion of the inlet portion of the flow passage is a variable volume damping cavity formed between a first damping face of the poppet and a second damping face of the liner, wherein a volume of the damping cavity varies based on a position of the poppet within the liner. ### Claim 19 (depends on 18) The check valve of claim 18, wherein a radial clearance is formed between the first damping face and the inlet portion of the flow passage such that a leakage flow is permitted from the damping cavity to the remainder of the inlet portion of the flow passage. ### Claim 20 (depends on 15) The check valve of claim 15, wherein the inlet portion of the flow passage has a first diameter and the outlet portion of the flow passage has a second diameter greater than the first diameter.