Hydrostatic Testing

Hydrostatic pressure testing is a method of testing pipelines that have been used for decades in the pipeline industry. Sunoco Pipeline L.P. utilizes hydrostatic tests for a variety of applications, such as strength testing prior to commissioning a newly constructed pipeline, testing pipeline replacement sections before being tied into the main pipeline, as a periodic pipeline reassessment method after a pipeline has been in operation, or to establish a new maximum operating pressure.   The hydrostatic tests are used to ensure that the pipe in our pipeline systems is suitable for service. We are committed to ensuring the safe, efficient and reliable operation of our pipeline system focusing on public safety and environmental protection.

Hydrostatic testing involves removing petroleum products from a pipeline and filling the pipeline segment to be tested with water. The water is then pressurized to levels higher than the normal pipeline operating pressure in order to verify the strength of the pipe and to identify potentially detrimental defects. The pipeline pressure is continuously monitored for the duration of the test which is typically a minimum of 8 hours for buried pipelines.  Our personnel may be seen patrolling the pipeline right-of-way during the testing process.

In the event a leak is detected during a hydrostatic test, we have personnel standing by to respond. Several methods can be utilized to sectionalize the line and identify a leak location. In some cases, the test water is colored with an environmentally safe, biodegradable, colored dye to assist in identifying a defect location, in the event of a leak. Upon completion of repairs, the line is again hydrostatically tested until a successful test is achieved. After achieving a successful hydrostatic test, the water is flushed from the line, refilled with product, and the line returned to normal operation.