(19)

(11)

EP 0 530 303 A1

(12)

(43) Date of publication: 10.03.1993 Bulletin 1993/10 (21) Application number: 91910570.0 (22) Date of filing: 10.05.1991

(51) International Patent Classification (IPC):  F16L 21/ 02( . ) (86) International application number: PCT/US1991/003297 (87) International publication number: WO 1991/018232 (28.11.1991 Gazette 1991/27)

(84) Designated Contracting States: DE FR GB IT NL SE (30) Priority: 16.05.1990 US 19900524160 22.01.1991 US 19910643747 (71) Applicant: BURKIT, John W. Kempton, PA 19529 (US)	(72) Inventor: BURKIT, John W. Kempton, PA 19529 (US) (74) Representative: Warren, Keith Stanley, et al  BARON & WARREN 18 South End Kensington London W8 5BU London W8 5BU (GB)