Flaws and defects in pipelines can result in significant problems. Fortunately, a new generation of tools are now available to detect circumferential crack-like features.

Once detected, pipeline operators have a few options to repair these flaws:

  • Replace the section of pipe;
  • Weld a metal sleeve over an extended area; or
  • Use any one of many possible non-welded repair technologies.

One main challenge for operators is choosing the right repair solution for their specific operating conditions.

Why not repair the flaw with traditional welding?

Welding a metal sleeve is the traditional approach, but it can also create problems. Welding can cause moisture to be absorbed, increasing the embrittlement of the repair.

There is also an increased risk of hydrogen-assisted and hydrogen-induced cracking as the metal cools. This embrittlement is impacted by:

  • the combined stress caused by shrinkage,
  • hydrogen molecules diffusing or spreading out from the weld,
  • and the formation of hard martensite.

For these reasons many operators are turning towards non-welding technologies.

Considering non-welding technologies

Novel composite or metal repair technologies are available that do not require welding to the carrier pipe. Some non-welding technologies have the potential to handle a large axial load. When selected and installed properly, these technologies can provide sufficient load-caring capacity.

There are also many non-welding technologies to choose from. No standardized testing has been completed at representative pipeline conditions to use as a reference.

This makes it very difficult for operators to know if a specific technology is acceptable for their pipeline. The consequences of picking the wrong technology for the wrong condition or flaw can be significant.

Evaluating non-welding pipeline technologies

C-FER Technologies is bringing the pipeline industry together in a joint industry project to scientifically evaluate the performance of these novel repair technologies.

This joint industry project is one of the first programs that can accurately replicate real pipeline conditions at pressure. Our work will impartially assess the performance and viability of multiple non-welding repair technologies.

In consultation with our JIP members, C-FER has compiled a large list of technologies to consider. Following a screening exercise, we created a test program to compare the performance of a selection of technologies under full-scale conditions.

Join the Joint Industry Project

This joint industry project is open to all pipeline operators interested in testing the new repair technologies. Members will learn what the best and safest technologies are for their operations and help direct testing.

For the first time, operators can conduct a side-by-side comparison of these non-welding repair technologies tested at pressure in an objective, non-biased, and highly instrumented laboratory environment.

Connect with Us:

If you are a pipeline operator interested in learning more about this JIP, contact us today.

Three types of full-scale testing

The project includes different types of full-scale testing using C-FER’s unique global research laboratory, such as:

Non-destructive tensile testing:

Different repair technologies were applied on a large diameter pipe and placed under pressure, like it would be in the field. They were then subjected to large axial tensions tests.

Many variables were monitored. The stiffness and effectiveness of load sharing between the pipe and repair collar was a key performance metric during these first tests.

Short-term destructive tensile testing:

This involves subjecting various non-welding technologies to a series of destructive tests with consistent flaw sizes. Specimens are subjected to destructive testing under constant pressure and displacement-controlled axial tension until they fail.

Upon completion of these tests, the repaired specimens will be evaluated against the results of the defect-free specimens.

Long-term destructive testing:

Adhesive and composite materials also have the potential to deteriorate over time. One of the purposes of the long-term testing is to address concerns with things like creep deformation in the repair.

During this type of testing, some non-welding repair technologies will be selected for long-term destructive testing using a custom apparatus.

The test will focus on things like the load capacity, overload capacity, maximum burst pressure, and failure mode of the technologies.

Solidworks rendering of C-FER's Tubular Testing System

Solidworks rendering of C-FER’s Tubular Testing System.

Interested in this Joint Industry Project?

If you want more information on this JIP or you are interested in joining, we want to connect with you.

Please complete the contact form and we will respond within 48 hours.

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