# US 10,119,636 B2 · Trapezoidal thread form having a wear indicator and high pressure connection fitting comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,636 B2 - Document ID: US10119636B2 - Status: Granted - Kind: B2 - Application number: 13/853,152 - Filed: 2013-03-29 - Published: 2013-10-03 - Granted: 2018-11-06 - Earliest claimed: 2012-03-30 - Assignees: Emerson Process Management Regulator Technologies, Inc. - Applicants: Emerson Process Management Regulator Technologies, Inc. - Inventors: Khashayar A. Nashery; Douglas J. Scheffler - Web page: https://patentgrep.com/patent/US10119636B2 ## CPC - F16L 15/06: characterised by the shape of the screw-thread - F16L 15/08: with supplementary elements (F16L15/04 takes precedence) - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL ## Abstract A trapezoidal thread form includes a thread having a trapezoidal cross-sectional shape, the thread including an apex surface, two side surfaces, and a valley; and a thread wear indicator formed in one of the apex surface and one of the side surfaces. The thread wear indicator may include a v-shaped channel formed in one of the apex surface and one of the side surfaces or the thread wear indicator may include a series of material layers, each layer having a physical characteristic that is different from an adjacent material layer. The thread wear indicator indicates excessive or unsafe thread wear when the v-shaped channel is indistinguishable from the apex surface or the side surface, or when a first layer wears sufficiently to show a second layer. ## Claims ### Claim 1 A trapezoidal thread form comprising: a thread having a trapezoidal cross-sectional shape, the thread including an apex surface and two side surfaces; and a spiral groove thread wear indicator formed in one of the apex surface and one of the side surfaces, the spiral groove running parallel to a top edge of the thread that is formed by an intersection of the apex surface and one of the side surfaces, wherein the thread wear indicator is a v-shaped channel having a depth that is between 5% and 25% of a thickness or height of the trapezoidal thread form. ### Claim 2 (depends on 1) The trapezoidal thread form of claim 1, wherein the v-shaped channel is formed in one of the side surfaces. ### Claim 3 (depends on 1) The trapezoidal thread form of claim 1, wherein the side surfaces are angled with respect to one another. ### Claim 4 (depends on 3) The trapezoidal thread form of claim 3, wherein the side surfaces are angled between 15° and 45°. ### Claim 5 A trapezoidal thread form comprising: a thread having a trapezoidal cross-sectional shape, the thread including an apex surface and two side surfaces; and a thread wear indicator formed in one of the side surfaces, wherein the thread wear indicator is a v-shaped channel having a depth that is between 5% and 25% of a thickness of the trapezoidal thread form, and wherein the v-shaped channel extends radially outward from a valley, a bottom of the v-shaped channel being substantially perpendicular to a top edge of the thread form. ### Claim 6 A trapezoidal thread form comprising: a thread having a trapezoidal cross-sectional shape, the thread including an apex surface and two side surfaces; and a thread wear indicator formed in one of the apex surface and one of the side surfaces, wherein the thread wear indicator is a layered surface that includes three layers. ### Claim 7 (depends on 6) The trapezoidal thread form of claim 6, wherein each layer has a different physical characteristic. ### Claim 8 (depends on 7) The trapezoidal thread form of claim 7, wherein the physical characteristic is color. ### Claim 9 (depends on 7) The trapezoidal thread form of claim 7, wherein the physical characteristic is texture. ### Claim 10 (depends on 7) The trapezoidal thread form of claim 7, wherein the physical characteristic is electrical conductivity. ### Claim 11 A threaded connection comprising: a male part having an outer thread form; a female part having an inner thread form; and a spiral groove thread wear indicator disposed on at least one of the outer thread form and the inner thread form, the spiral groove running parallel to a top edge of the outer thread form or of the inner thread form, the top edge being formed by an intersection of an apex surface and a side surface of the outer thread form or of the inner thread form, the thread wear indicator providing a visual indication of excessive thread wear, wherein the thread wear indicator is a v-shaped channel having a depth that is between 5% and 25% of a thickness or height of the thread form. ### Claim 12 (depends on 11) The threaded connection of claim 11, wherein one of the outer thread form and the inner thread form is a trapezoidal thread form. ### Claim 13 A threaded connection comprising: a male part having an outer thread form; a female part having an inner thread form; and a thread wear indicator disposed on at least one of the outer thread form and the inner thread form, the thread wear indicator providing a visual indication of excessive thread wear, wherein the thread wear indicator is a v-shaped channel having a depth that is between 5% and 25% of a thickness or height of the thread form, and wherein the v-shaped channel is formed in a side surface of one of the outer thread form and the inner thread form and the v-shaped channel extends radially outward from a valley, a bottom of the v-shaped channel being oriented substantially perpendicular to a top edge of the thread form. ### Claim 14 A threaded connection comprising: a male part having an outer thread form; female part having an inner thread form; and a thread wear indicator disposed on at least one of the outer thread form and the inner thread form, the thread wear indicator providing a visual indication of excessive thread wear, wherein the thread wear indicator includes at least three layers. ### Claim 15 (depends on 14) The threaded connection of claim 14, wherein each layer has a different physical characteristic.