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Priority claimed from GB838330662Aexternal-prioritypatent/GB8330662D0/en
Priority claimed from GB838330663Aexternal-prioritypatent/GB8330663D0/en
Application filed by Dresser IndfiledCriticalDresser Ind
Priority claimed from EP84307927Aexternal-prioritypatent/EP0142377B1/en
Application grantedgrantedCritical
Publication of ATE39856T1publicationCriticalpatent/ATE39856T1/en