Williams developed an enhanced pipeline integrity management plan and began using it in January 2003 — even before new pipeline safety regulations were enacted.
Although the pipeline safety regulations focus on high consequence and/or high risk areas, Williams’ overall pipeline integrity plan covers rigorous inspections for our entire pipeline system.
Our plan complies with the protocol established in the American Society of Mechanical Engineers Regulation B31.8-s, which approves one of three inspection procedures: smart pig, hydrostatic or direct assessment. Our plan incorporates all three types depending on the location, length and threats associated with the pipe to be tested.
We build safety into our pipelines.
- Before a pipeline is built or expanded, Williams researches and plans to ensure the safe construction and operation of the system. When planning a pipeline project, Williams does its best to minimize the impact to communities by locating the pipeline along existing rights of way, roadways or other utility corridors.
- Williams’ pipelines are engineered according to strict industry design and construction standards (ASME code B31.8 and DOT 49 CFR Part 192).
- We build our pipelines with welded, high strength steel pipe. Pipeline representatives inspect the pipe at the mills during fabrication to ensure its quality meets or exceeds both federal and industry standards.
- Protective coatings are applied at the mill and on on-site to prevent moisture from coming into contact with the metal.
- Williams’ representatives inspect all aspects of the construction of the pipeline and related facilities. The welds linking the pipe joints are x-rayed to ensure integrity.
- Once the pipeline is in the ground, but before it is placed in service, it undergoes hydrostatic testing. This means the pipeline is tested with water at pressures higher than normal operating pressure to ensure the pipeline’s integrity.
- Williams buries its pipelines at least 36 inches underground.
- Automatic shut-off valves are installed for safety.
- After the pipeline is installed, we put in a low-voltage electrical system called cathodic protection that, along with the pipe’s coating, is designed to prevent corrosion of the steel pipeline.
General inspection procedures and preventing/assessing third party damage
- Aerial and ground inspection of pipeline rights of way: Heavily populated areas are inspected and patrolled more frequently. We strive to keep our pipeline rights of way clear of trees, fences, structures and debris to allow easy identification and monitoring of our facilities.
- Leak detection surveys: Leak surveys must be conducted at least once every calendar year. More frequent testing is done depending on the nature of operations and location of the pipeline.
- Line markers: Markers are posted along our rights of way to let you know there is a pipeline in your area. These markers are checked annually.
- 24-hour monitoring: Pipeline personnel monitor our systems 24 hours a day, 7 days a week. Our equipment can detect even a slight change in pressure or flow. Dispatchers can quickly activate emergency shutdown procedures if they detect a problem.
- Emergency response training: Pipeline personnel are trained once a year on emergency response procedures and plans. Williams’ representatives meet regularly with local emergency responders to review emergency response procedures.
- Public education: Written information about recognizing leaks and properly reporting pipeline emergencies is distributed annually to the public, appropriate government agencies and third party excavators. Williams actively participates in local One-Call programs in each of the states where we operate.
- Wheel load calculations: Before any third party vehicles or equipment are allowed to cross the pipeline, company engineers perform stress calculations to ensure the integrity of the pipe.
- Blast calculations: Before blasting is permitted near the pipeline right of way, company engineers perform stress calculations to insure the integrity of the pipeline.
Corrosion and Coating Inspection
- Cathodic protection: Low voltage, electrical systems, called cathodic protection systems, are installed on all pipeline facilities to prevent corrosion. Company personnel checks the voltage and amperage every two months as well as the pipe-to-soil potentials and rectifiers. In addition, annual surveys are completed.
- Coating inspection: Any time a pipeline is excavated, company personnel inspect the pipeline and coating for evidence of damage or corrosion.
- Smart pig program: Internal, electronic inspection devices, called smart pigs, are used to detect any anomalies. Portions of Williams have been smart pigging their pipeline systems since 1987.
Equipment and Control Systems Inspection and Maintenance
- Emergency shut down tests: Each compressor station along the pipeline route performs annual emergency shut down tests. Gas sensors are tested as well as remote control shut down devices.
- Mainline valves: Valves are maintained and partially operated at least once a year.
- Emergency pipe inspection: Each division along the pipeline route maintains a certain amount of emergency pipe. Company personnel inventory and inspect this pipe each year.