# US 11,079,032 B2 · Regulating overtravel in bi-furcated plugs for use in valve assemblies > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,032 B2 - Document ID: US11079032B2 - Status: Granted - Kind: B2 - Application number: 16/369,906 - Filed: 2019-03-29 - Published: 2019-07-25 - Granted: 2021-08-03 - Earliest claimed: 2017-09-25 - Assignees: Dresser, Inc. - Applicants: Dresser, LLC - Inventors: Thomas Henry Cunningham - Web page: https://patentgrep.com/patent/US11079032B2 ## CPC - F16K 27/02: of lift valves (for reducing the flow resistance of screw-spindle lift-valves F16K1/06) - F16K 1/12: with streamlined valve member around which the fluid flows when the valve is opened - F16K 1/42: Valve seats (for double-seat valves F16K1/44) - F16K 3/24: with cylindrical valve members - F16K 39/022: {using balancing surfaces} - Y10T 137/1624: Destructible or deformable element controlled - 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)} - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A gap control device that works with a plug on a valve assembly for use in high-temperature applications. The plug may include two parts and a compressible seal that, when compressed, engages with an adjacent wall of a cylinder or “cage” typical of a trim assembly. In one embodiment, the gap control device forms a hard stop that expands in response to high temperatures. This feature prevents excess over-travel between the two parts of the plug in the high-temperature applications so as to limit stress and wear on the compressible seal. ## Claims ### Claim 1 A valve assembly, comprising: a trim assembly with a closure member comprising two pieces that are moveable in a first direction relative to one another under load, each of the pieces having a surface that is perpendicular to the first direction; and a gap control device disposed in proximity to the two pieces of the closure member, the gap control device comprising a hard stop that resides between the surface of the two pieces and that prevents relative movement between the two pieces, wherein the hard stop comprises a thermally-active member disposed in one of the two pieces of the closure member and comprised of material that expands and contracts in the first direction between the two pieces in response to different temperatures, and wherein the material of the thermally-active member expands under temperature at a rate that is different from material of at least one of the two pieces of the closure member. ### Claim 2 (depends on 1) The valve assembly of claim 1, wherein the hard stop forms a core that extends into one of the two pieces of the closure member. ### Claim 3 (depends on 1) The valve assembly of claim 1, further comprising: a compressible seal disposed between the two pieces of the closure member. ### Claim 4 (depends on 1) The valve assembly of claim 1, further comprising: an annular ring comprising resilient material disposed between the two pieces of the closure member. ### Claim 5 (depends on 1) The valve assembly of claim 1, wherein the hard stop is cylindrical. ### Claim 6 (depends on 1) The valve assembly of claim 1, wherein the hard stop has a material composition that is homogenous. ### Claim 7 A valve assembly, comprising: a cylinder; a plug disposed inside of the cylinder, the plug comprising a first part and a second part that are moveable in a first direction relative to one another in the cylinder, each of the first part and the second part having a surface that is perpendicular to the first direction; and a gap control device that resides between the surface of first part and the second part and that prevents relative movement between the first part and the second part, wherein the gap control device comprises a thermally-active member having an end that changes position in the first direction relative to the first part and the second part in response to temperature differential of material that flows proximate the plug, and wherein the material of the thermally-active member expands under temperature at a rate that is different from material of at least one of the first part and the second part of the plug. ### Claim 8 (depends on 7) The valve assembly of claim 7, wherein the thermally-active member comprises a cylindrical plug in one of the first part or the second part. ### Claim 9 (depends on 7) The valve assembly of claim 7, wherein the thermally-active member has a material composition that is homogenous. ### Claim 10 (depends on 7) The valve assembly of claim 7, further comprising: a resilient seal member disposed between the first part and the second part. ### Claim 11 (depends on 7) The valve assembly of claim 7, further comprising: a valve stem extending through the first part and the second part; and a coil spring disposed on an end of the valve stem. ### Claim 12 A valve assembly, comprising: a two-part plug with a first part and a second part, each with a surface that is perpendicular to a direction of travel of the two-part plug; and a hard stop integrated into the two-part plug between the surface on the first part and the second part, the hard stop comprising thermally-active material that expands under temperature at a rate that is different from either the first part or the second part, wherein the hardstop has an end that changes position in the direction of travel relative to the first part and the second part in response to temperature differential of material that flows proximate the plug. ### Claim 13 (depends on 12) The valve assembly of claim 12, wherein the hard stop is cylindrical. ### Claim 14 (depends on 12) The valve assembly of claim 12, wherein the hard stop has a material composition that is homogenous. ### Claim 15 (depends on 12) The valve assembly of claim 12, wherein the hard stop forms a stopping surface disposed in space formed in the two-part plug. ### Claim 16 (depends on 12) The valve assembly of claim 12, further comprising: resilient seal member integrated into the two-part plug that circumscribes the hard stop. ### Claim 17 (depends on 12) The valve assembly of claim 12, further comprising: a Belleville washer integrated into the two-part plug. ### Claim 18 (depends on 12) The valve assembly of claim 12, further comprising: an annular ring that circumscribes the two-part plug. ### Claim 19 (depends on 12) The valve assembly of claim 12, wherein the two-part plug comprises openings to allow upstream or downstream pressure to act on both sides.