(19)

(11)

EP 0 042 398 A1

(12)

(43) Date of publication: 30.12.1981 Bulletin 1981/52 (21) Application number: 81900134.0 (22) Date of filing: 17.12.1980

(51) International Patent Classification (IPC):  B63C 11/ 40( . ) E21B 43/ 013( . ) F16L 1/ 26( . ) E21B 43/ 01( . ) F16L 1/ 16( . ) F16L 11/ 12( . ) (86) International application number: PCT/NL1980/000040 (87) International publication number: WO 1981/001735 (25.06.1981 Gazette 1981/15)

(84) Designated Contracting States: AT CH DE FR GB LI LU NL SE (30) Priority: 18.12.1979 NL 19790009107 (71) Applicants: DUYSTER, Hoite Cornelis NL-2597 NP The Haque (NL) WAVIN B.V. NL-7700 AD Dedemsvaart (NL) DUYSTER, Tjerk Hans NL-2597 JC The Haque (NL)	(72) Inventor: DUYSTER, Tjerk Hans NL-2597 JC The Haque (NL)