Steel bellows for reinforced concrete propulsion pipes, has coatings applied on carrying side of steel flange, and on circulation protection device and stay bolts with quartz sand spray

摘要

A steel bellows has coatings (a) applied on the carrying side of the steel flange of a propulsion pipe, on the circulation protection device and stay bolts with quartz sand spray, and on the bellows upper surface. The coating on the device and the stay bolts blocks their contact with metallic parts of the pipe.