METHOD OF HYDRAULIC CONTROL VALVE REPAIR Russian patent published in 2010 - IPC B23P6/00 B23H5/00 

FIELD: process engineering.

SUBSTANCE: invention relates to repair of machine assembly units and parts and can be used at repair shops etc. Proposed method comprises machining spool bores by diamond broach bit to remove wear traces from work surfaces, applying a layer of low- or medium-carbon steel on said work surfaces by electric-arc processing in automated mode, subsequent grinding and lapping of said work surfaces, applying brass film thereon by finishing antifriction nonabrasive method, grinding valve seat to produce bore sharp edge, removing wear traces from the valve sealing taper surface, seat grinding till luster on ground surfaces. Sealing taper surface of the machined valve is hardened by hard-alloy electrode by electric-spark method with discharge power of 0.13 to 1.66 J.

EFFECT: increased MTBR thanks to improved properties of valve taper sealing surface.

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