Tack welding jig for large dia pipe - made by bending metal plate into pipe with longitudinal slot, where Jig presses slot edges together for tack welding

摘要

The jig includes a ring frame carrying a circular row of supports (1) which can be adjusted radially w.r.t. the longitudinal axis of the pipe to be tack welded. The radial adjustment is achieved via a motor, and each support (1) ends in a pivot shaft on which a plate (6) is mounted; and the angle of plate (6) can be adjusted clockwise or anticlockwise via two variable limit stops. Each plate (6) carries a longitudinal row of rolls, which are driven radially inwards against the outside surface of a pipe bent from metal plate and possessing a longitudinal slot. The edges of the slot are thus pressed together ready for tack welding. The pipes may have widely different dias. but can still be aligned for tack welding by the jig.