Oil pipeline riser coupling for offshore platform - has inner sleeves held inside internally threaded coupling piece by top flange

摘要

Coupling for riser of oil pipeline, used e.g. on offshore platform, has rotating coupling member (I) and inner sleeve both connected by flange on top. Lower sleeve part is secured by screw thread inside coupling member and butts against inner sleeve, partly projecting inside it. This tread is interrupted, consisting of radial portions with clearance cut units between. Top flange includes two guide sleeves, projecting downwards, to receive securing pin, whose nose passes through projections on inside of the top coupling parts. Coupling member and lower sleeve each have stops to limit rotation.