(19)

(11)

EP 0 861 400 A1

(12)

(43) Date of publication: 02.09.1998 Bulletin 1998/36 (21) Application number: 96925002.0 (22) Date of filing: 19.07.1996

(51) International Patent Classification (IPC):  F16L 55/ 165( . ) (86) International application number: PCT/GB1996/001735 (87) International publication number: WO 1997/004269 (06.02.1997 Gazette 1997/07)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 20.07.1995 GB 19950014883 (71) Applicant: Polytech Research & Development Limited Manchester M15 6SE (GB)	(72) Inventors: CONNOR, Raymond Buxton, Derbyshire SK17 9EH (GB) WILDE, Paul, Anthony Buxton, Derbyshire SK17 6SG (GB) (74) Representative: Middlemist, Ian Alastair, et al  Wilson Gunn M'Caw, 41-51 Royal Exchange, Cross Street Manchester, M2 7BD Manchester, M2 7BD (GB)