Concrete pump with S-tube valve assembly with retainer ring for spring

摘要

A concrete pump includes a hopper having a plate with a pair of openings and an S-tube valve assembly which is movable between the two openings. The valve assembly includes an S-tube which is connected to a mounting plate which is pivotally mounted on the hopper. A wear ring is movably supported within an opening in the valve assembly and engages the hopper plate. A retainer ring is positioned within the opening of the valve assembly and engages a flange on the valve assembly. A resilient spring is positioned between the wear ring and the retainer ring and resiliently urges the wear ring against the hopper plate.