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Hydrostatic Pipeline Testing

Rodney Vasquez | July 24, 2023

Overcoming Risk with Third Party Support

Hydrostatic testing a pipeline is a necessary part of the commissioning process during new construction to verify structural integrity and to meet OT requirement for defining a Maximum Operating Pressure. Tests can also re-certify the pipeline after modifications or changes in service. Hydrotests can be used as an alternative or enhancement to In-Line Inspection techniques, especially for crack-like defects.

Each mainline test has unique challenges that should be planned for prior to executing the test. A few of the primary concerns include water fill without entraining air, temperature stabilization and accurate temperature measurement. Working with an expert testing partner you can trust saves time and money and ensures proper compliance and certification in support of efficient project start up and operation.

History of Testing: Changing Complexity and New Requirements

Higher testing pressure and higher % SMYS (Specified Minimum Yield Strength) requirements started in the 1960s. ASME B31.1.8 was the first standard to require post-construction testing. Modern tests occur at high % SMYS levels and can employ a “spike” test interval (short time duration) as an assessment of narrow, crack-like defects that may be present.

While Maximum Operating Pressure (MOP) testing has not significantly changed over the past several decades, there have been a few newer applications that have been added to the testing approaches, such as “spike” testing at high % SMYS of the pipe. Precise and detailed planning and thorough documentation of the plan will improve the probably of a successful hydrostatic test. In addition to all the planning, clear communication of expectations and testing requirements is essential for success throughout all phases of the planning and execution of the test.

Benefits of Third-Party Hydrostatic Testing Support

Working with a third part testing partner is more efficient and cost effective when it comes to proper pipeline certification. To leverage the full benefits of third-party testing, it is important to seek a highly qualified and experienced team who understands your goals.

Specialized Equipment

Pipeline operators often do not own the specialized equipment required for mainline hydrostatic testing, including high flow rate and high-pressure pumps that are used for the displacement of product with water. Many hydrostatic testing evolutions require external resources with equipment and experience to increase the probably of a successful test. A testing partner will have access to modern hydrostatic testing equipment that complies with the U.S. Department of Transportation (DOT) standards and should have experience with implementing testing processes in accordance with DOT requirements.

Engineering Data and Documentation

A successful hydrostatic test will produce the engineering data necessary for the MOP of the pipeline. Successfully completing the hydrostatic test and providing the necessary documentation is essential when the pipeline operations are audited by State or Federal officials. Without a properly conducted hydrostatic test and the documentation to justify the MOP of the pipeline, issues could become a regulator’s audit findings. A good third-party testing partner understands the pitfalls related to poor documentation and incomplete test data records. By managing this process from start to finish with full attention to detail and proper procedure, a third party ensures the continued smooth operation of your project.

Compliance and Certification

Certifying the results of hydrostatic testing requires support from a qualified individual or team of experts. Independent contractors can attest that the test was completed successfully and will provide the required compliance and engineering reports associated with the test. Repeating a test because of a planning mistake, failure in communication or an issue with the pipeline can be very expensive. Third party certification can prevent the risk, cost and inefficiency of having to shut a pipeline down to repeat a test.

Cost Savings and Operational Efficiencies

A trusted third-party tester can help you focus your internal resources on the larger scope of executing the pipeline project successfully rather than be caught up in the details of properly executing the hydrostatic test. An experienced testing team will be able to make final determinations of a “good” test per ROPI calculations.

Third-party testers also help eliminate the qualification and training costs associated with tasking in-house staff with managing the hydrostatic test and associated recordkeeping. With an independent view of lessons learned and improvement opportunities, an outside testing group can help advance and achieve operational efficiencies for future testing.

Next Steps for Successful Hydrostatic Testing: TRC Can Help

Partnering with a third-party hydrostatic testing organization as early as the project planning phase is helpful. A qualified team should review your company’s assets and test plan to ensure that the tests will meet the appropriate standards and codes prior to the hydrostatic test date. Having the testers onsite to examine the details of the test set-up, testing equipment and P-V plot preparation and to witness the test firsthand is essential. After the test has been completed, written documentation, forms and a report ensure all findings are appropriately documented.

As a trusted third-party tester, TRC’s engineers plan, design, QA/QC, witness and certify hydrostatic tests and provide the associated required documentation to support successful pipeline projects. Our pipeline experts leverage ensures our nationwide experience and expertise to meet your specific testing challenges and to provide the best solutions to protect your assets.

We are also skilled in training pipeline operators in the skills necessary to successfully oversee hydrostatic testing, ensuring that your employees know what questions to ask and follow critical steps so that the test is appropriately executed.

For more information about our solutions or to discuss your unique project needs, contact Rodney Vasques at

Rodney M. Vasquez

Rodney currently supports Pipeline Integrity Project efforts at TRC, bringing his experience in pipeline design, construction, operations and integrity management. In his role, he oversees projects supporting gas and liquids pipelines throughout North America with capabilities in risk analysis and management, integrity assessments (ILI, hydrotesting or ECDA), regulatory compliance, corrosion mitigation, pipeline design and construction, repairs, leak detection, P&M Measures, EFRDs, Active Corrosion Studies and cathodic protection. Prior to TRC, he has spent several years in engineering roles supporting Exxon Mobil’s pipeline integrity efforts. Rodney has a BS in Aerospace Engineering from The University of Texas at Austin. He has taken dozens of graduate courses in Mechanical Engineering and project management. Rodney can be contacted at

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