Corrosion-restistant pipe coupling structures.

摘要

A corrosion-resistant pipe coupling (2) made of carbon steel has on its inner surface an intermediate annular projection (8) directed radially inward. At least an innermost part of the annular projection (8) is formed of corrosion-resistant material such as stainless steel. The annular projection (8) is covered by a corrosion-resistant annular member (12), (21) or (29) which is secured by friction welding, electron beam welding, an adhesive or mechanical engagement. The annular member prevents corrosion of the coupling by corrosive fluids flowing in pipes (1).