Kiefner and Associates
, our engineering consultancy business in the US, together with the Applus+ Pipeline Integrity Group, were approached by a large pipeline operator on the West Coast of the US to develop a non-destructing testing (NDT)
and engineering programme to eliminate costly and time-consuming hydrostatic testing from its compressor stations. Hydrostatic testing was required by regulatory processes, given the lack of traceable records on much of the equipment and associated piping at the compressor stations.
The pilot project identified a suitable station, whose piping and equipment had been significantly upgraded and whose material records were adequate for the project. This station proved the ideal location to perform the NDT on-site, as well as the follow-up engineering analysis. The results were then studied and compared with the existing records to validate both the NDT process and the subsequent engineering assessments.
The pipeline system for this particular project presented several unique challenges. The station is in an environmentally sensitive area, with an endangered tortoise species whose presence severely limits the amount of heavy equipment that can be used. The vast majority of the work to excavate the underground piping was thus performed either by hydrovac or by hand. The proposed NDT techniques require significant amounts of clearance to attach the various tools. In addition, gas flow requirements meant that the work was delayed until the onset of summer, when temperatures were routinely higher than 37°C for most of the working day.
A multidisciplinary approach was developed between the engineers at Kiefner and Associates and Applus+, employing overlapping data sets. A suite of testing techniques involving Frontics AIS 2000 indenters, an Oxford OES Mass Spectrometer, and ultrasonic hardness testing were used to confirm the material properties. The second phase of the project involved more traditional NDT approaches, with the long seams and girth welds inspected using IWEX and multi-group encoded Phased Array.
More traditional methods, such as Magnetic Particle Inspection
and Gamma Radiography, were employed to provide additional information on surface conditions and the integrity of pipe to fitting welds.
The client was satisfied with the outcome, with additional sites now being assessed for their feasibility to employ these cost-saving methods. Being able to perform this work without taking piping and equipment out of service is highly advantageous for clients, who can schedule such evaluations around their gas flow schedules, secure in the knowledge that their systems remain compliant with federal regulations.
Through its advanced NDT solutions and diverse skills and capabilities, Applus+ can deliver technical support that minimises the level of risk to assets and maintains productivity, while simultaneously reassuring clients that their assets comply with all applicable standards.