Issues arising from testing the integrity of existing pipelines often differ from those associated with new construction assets – from the reason for the commissioning of the test, to the effective loss of service time caused by the work.
The objective in all cases is to achieve the highest possible test-pressure-to-operating-pressure level; however, considerations, such as the anticipated number of test breaks, the types of defects expected, and the limits on downtime, may force compromises.
If you are planning to conduct a hydrostatic test of a new or existing pipeline, Applus RTD can assist in the selection of the most appropriate test pressure, which should be as high as feasible without causing excessive amounts of damage.
This usually involves testing to 100 percent of SMYS or more and monitoring by means of a pressure-volume plot.
Distribution of pipe yield strengths based on pipe mill data, pressure-volume plotting, and acceptable limits on strain, elevation differences and test section lengths, and the impact of the test on pipe-manufacturing imperfections that are too small to be revealed by the test are all considered.
Based on the anticipated service and operating conditions, Applus RTD can also work to establish service-life projections for the various choices of pressure levels.
Applus RTD's knowledge and experience will help in delivering hydrostatic testing in the safest, most efficient way. We can suggest means to minimize test breaks and downtime. Whatever the benefits of the test in terms of demonstrating an asset's remaining service life and in any test, it is important to examine recorded failures to determine their cause.