10 Year Anniversary of Integrity Management
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Over the course of the last ten years, society has come to depend on smart phones, computer tablets, 3D television and global positioning systems. The use of these devices and related technology has improved the quality of our lives as well as our safety. The same can be said for pipelines and integrity management programs.
The concept of pipeline integrity management has evolved over time as technology has improved and operators have sought new ways of examining and confirming the condition of their pipeline systems. Because pipelines are buried, such an examination poses a unique problem for operators as simply digging up even a single section of the buried steel may be difficult for a variety of reasons. Historically, the primary method of confirming a pipeline’s integrity has been to hydrostatically test the line. This process involves pumping a segment of the pipeline full of water and holding a specific pressure over a period of time. Such a procedure confirms the integrity of the system and the ability of the pipe to transport the liquid or gas up to a certain pressure.
As technology has improved, so has the pipeline industry’s ability to examine the internal and external condition of the pipe. Today, pipeline operators also use internal inspection devices as a way of inspecting the pipeline to locate and characterize flaws. Through this process, a device is inserted into the pipeline that uses a variety of sensors to capture data about the thickness of the steel and areas where potential anomalies are located.
The Pipeline and Hazardous Materials Safety Administration
(PHMSA) began adopting a series of regulations in 2001 that require operators to examine pipelines that meet specific criteria at regular intervals. Operators are required to prioritize risk, initiate preventative and mitigative measures, and inspect those pipelines determined to be of the highest risk first. The criteria used to determine whether a pipeline poses an increased risk are identified through an evaluation of specific conditions near the pipeline. Areas considered to be of higher risk are referred to as high consequence areas, or HCAs, and include locations that are environmentally sensitive, more densely populated or navigable waterways. Unusually sensitive areas, or USAs, include those locations where drinking water or ecological resources would be more unusually susceptible to environmental damage from a hazardous liquid pipeline release. USAs are considered to be a smaller subset of HCAs.
The first 10 years of this program has resulted in an overall increase in knowledge about the current condition of our nation’s pipeline infrastructure. The testing has also resulted in safer systems as problems identified through the assessments are either repaired or monitored more closely. While information is only available through 2010, more than 135,000 miles of transmission pipeline have now been tested and more than 40,000 repairs made. This represents 45 percent of the total mileage of transmission pipelines.
Integrity management is also being addressed by local distribution companies, or LDCs. PHMSA adopted rules requiring LDC operators to develop written distribution integrity management programs (DIMP) by August of 2011. The primary difference between integrity management programs for transmission pipelines and those of LDCs is usage of internal inspection devices. LDCs are not able to use internal inspection devices because of the relatively small diameter of some of their pipelines – some are as small as one-half inch in diameter. Like the requirements for transmission pipelines, each LDC operator will be required to demonstrate the knowledge of their system as well as create a plan to identify the threats and rank the potential risks to the pipeline. The operator must then implement processes to address those risks, measure performance and evaluate the overall program. Like the integrity management requirements for transmission pipelines, LDCs will review their program and implement improvements.