(19)

(11)

EP 0 573 483 A1

(12)

(43) Date of publication: 15.12.1993 Bulletin 1993/50 (21) Application number: 92905269.0 (22) Date of filing: 27.02.1992

(51) International Patent Classification (IPC):  F16L 15/ 00( . ) E21B 17/ 042( . ) F16L 15/ 06( . ) (86) International application number: PCT/GB1992/000350 (87) International publication number: WO 1992/015815 (17.09.1992 Gazette 1992/24)

(84) Designated Contracting States: GB IT NL (30) Priority: 28.02.1991 GB 19910004271 (71) Applicant: HUNTING OILFIELD EQUIPMENT HOLDINGS LIMITED London SW1Y 5BQ (GB)	(72) Inventors: LUMSDEN, Norman Aberdeen AB1 6UJ (GB) PERRIE, Archibald Aberdeen AB1 6BG (GB) (74) Representative: Harrison, Philippa Dinah, et al  A. A. THORNTON & CO Northumberland House 303-306 High Holborn London WC1V 7LE London WC1V 7LE (GB)