COMPRESSION APPARATUS

A compression apparatus (10) for compressing a tubular structure (12) which is ultimately formed into a hollow structure (20) such as a pipe (20). The compression apparatus (10) comprises contact elements (60) arranged in two sets, being an upper set (61) and a lower set (62). The contact elements (60) in the two sets (61, 62) are adapted to move along a compression section (41) in a coordinated sequence, whereby a portion (12a) of the tubular structure (12) within the compression section (41) is compressed between pairs (63) of opposed contact elements (60). The compression apparatus (10) further comprises registration means (110) for causing respective pairs (63) of opposed contact elements (60) to be maintained in registration with each other while moving along the compression section (41). The registration means (110) may comprise counterpart registration elements (113) on the respective pairs (63) of opposed contact elements (60). The counterpart registration elements (113) may comprise registration pins (117), and registration slots (119). In one arrangement, the contact elements (60) are adapted to provide rigid contact with the tubular structure (12). In another arrangement, at least some of the contact elements (60) may be adapted to provide compliant contact with the tubular structure (12).