Sealing element, particularly for shut-off and regulating valves, and process for its production

US5927727A · kind A · utility

Assignee

• Friedrich Grohe AG · DE

Inventors

• Friedrich Wagner · Balingen, DE
• Hans-Peter Strelow · Glückstadt, DE

Key dates

• Filing date: May 20, 1997
• Grant date: Jul 27, 1999
• Expiry date: May 20, 2017

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16K25/005
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A sealing element, particularly for shut-off and regulating valves, comprising a tabular, piston-shaped or spherical shut-off body of a ceramic material having a hard material layer containing carbon and silicon applied to a sealing surface of the shut-off body by plasma chemical vapor deposition or plasma polymerization, in a coating chamber. The hard material layer comprises a bonding layer component applied to the sealing surface of the shut-off body and a subsequent sliding layer component. The carbon-containing bonding layer component has a first silicon content favoring adhesion to the sealing surface of the shut-off body and the subsequent carbon-containing sliding layer component having a second silicon content lower than that of the bonding layer component to achieve low coefficients of sliding friction and static friction. The sliding layer component is selected so as to be essentially thin and the bonding layer component is selected so as to be comparatively thick to take up the residual stresses of the sliding layer component. The hard metal layer is heat treated.