Page 393 - Pipelines and Risers

Use of High Strength Steel 36 1

These three projects have demonstrated that large diameter X80 pipe can be manufactured
consistently for long pipelines. Therefore, XSO strength pipe should not be considered to be
special or developmental for land pipelines at least.

The approach to the X80 projects was significantly different when the welding procedure and
consumables were selected. The PGMAW welding procedure had the highest weld metal
toughness properties, although the other procedures satisfied the requirements with a good
safety margin. However, the PGMAW procedure was less operator friendly than the GMAW
procedures. It is the opinion of NOVA that PGMAW is an acceptable alternative to GMAW.
Their research proved conventional procedures and consumables were acceptable for X80
Pipe.

The field welding of the X80 pipe did not present any difficulty for the Ruhrgas and
Mitzihwin projects. These projects demonstrated that conventional mechanized welding using
the GMAW process can produce consistent, high quality welds for onshore pipelines.

In Norway, EXPPE JIP was conducted by Statoil, together with linepipe manufacturers (e.g.
Europipe), design office (J P Kenny) and installation contractors, in order to qualify X80
linepipe for (offshore) export pipelines.