A swivel coupling element for use in sealingly coupling a tubular element to an annular coupling flange. The swivel coupling element includes an annular mounting flange having a leading end which defines a seating face for seating on the seating face of such an annular coupling flange, the annular mounting...http://www.google.es/patents/US4381871?utm_source=gb-gplus-sharePatente US4381871 - Swivel coupling element
