GE
Measurement & Control
Krautkramer Testing Machines
Submerged Arc Welded (SAW) Pipes
SNUP Testing Machine Series
Introduction
Longitudinally or helically SAW welded pipes are still the
major component for pipeline constructions around the
world. Within the manufacturing process, the pipes
have to be ultrasonically tested according to industryaccepted standards. As a result, ultrasonic testing of
the weld seam is well-established in production of both
types of pipes.
The ultrasonic test is performed after welding and/or
after the hydrotester resp. expander. While the test
after welding is usually for internal process control, the
inspection after the hydrotester/expander is normally
the final verification of quality before the pipe is finished
and approved for shipment to the customer.
SAW pipes are inspected to detect three main flaw
types that can occur during manufacturing:
Longitudinal defects along the weld axis, transverse
defects perpendicular to the weld axis; and laminations.