The total quantity of pipe ordered was 550 km allowing for 340 km of export pipeline with the balance for the collection header. The total tonnage was 207,690 t.
Why did QGC select Baosteel as the sole supplier?
Following a competitive tender and a careful technical bid evaluation process, the pipe order was placed with Howa Trading Co. Ltd, a wholly-owned subsidiary of Baoshan Iron & Steel Co Ltd (Baosteel) of the People’s Republic of China. This was the first major export of high-strength longitudinal seam submerged arc-welded (LSAW) pipe outside of China by any Chinese company, and is the largest order of line pipe by Baosteel for a single pipeline project.
Prior to the award of the project, QGC required the development of an agreed project- and contract-specific manufacturing procedure specification (MPS), covering steel making, plate rolling, pipe making, and coating and lining. This process allowed the purchaser to have confidence and certainty in the agreement rather than relying upon pre-production negotiations following the award of the contract, when the purchaser has reduced leverage.
Baosteel provided a detailed project-specific MPS at bid stage, and this document evolved further through pre-production and manufacturing procedure qualification. Together with highly detailed inspection and test plans, the MPS is central to the specification, inspection and quality-control processes of both parties. The development of the MPS was especially helpful in assisting mutual understanding in a new relationship involving different cultures.
Manufacturing procedure qualification testing (MPQT), including a range of special tests such as longitudinal tensile tests, fracture propagation and initiation transition temperature tests and full-scale burst tests were carried out on each of the three wall thicknesses in both the as-manufactured and as-coated condition before the commencement of production.
Key aspects of the specification that Baosteel agreed to meet included a low value of yield-to-tensile ratio on round bar (unflattened) tensile tests, the conduct of full-scale pressure tests to measure yield strength and burst pressure before and after coating to assess the degree of strain ageing caused in the fusion-bonded epoxy coating process, and the performance of field weldability tests.
The MPQT process demonstrated to QGC and other stakeholders that the Baosteel pipe is equal to or better than best practice in all respects and provided assurance that construction and operation risks were addressed and mitigated to low or negligible levels consistent with the requirements of AS2885.