Regulators require minimum federal safety standards for pressure uprating as described in 49 CFR Part 192 Subpart K. Pipeline uprating to a pressure that will produce a hoop stress of 30% or more of SMYS in steel pipelines require a series of documented integrity assessments to ensure the pressure uprating will not adversely affect the safe operation. The objective of this paper is to disseminate a process that operators can use to develop an effective integrity assessment guide for pressure uprating. This guide exceeds the requirements established in §192.555. The combination of External Corrosion Direct Assessment (ECDA), In-Line Inspection (ILI), and hydrostatic testing is used in conjunction to identify a variety of time dependent and time independent threats. A systematic approach for chronological implementation of assessment types for pressure uprating has been validated through a successful case study.
The annual natural gas demand in the United States surpassed 31 trillion cubic feet in 2019. This is over a 500% increase from demand in the 1950's (5.7 trillion cubic feet) [1]. As gas demand continues to rise, pipeline operators have limited options to meet demand requirements. Pressure uprating is one option that can be leveraged for certain pipelines to meet the increased demand economically. The pipeline pressure is increased to create a larger pressure differential from one end to the other which in turn increases the flow rate of the natural gas.
Pipeline pressure is a critical operational variable that must be determined and continuously monitored by the pipeline operator to ensure the natural gas can safely travel appropriate distances and meet the market demand. Pipeline pressure is also heavily scrutinized by the Pipeline and Hazardous Materials Safety Administration (PHMSA) to ensure compliance with Title 49 Code of Federal Regulations (CFR) Part 192 - Transportation of Natural and Other Gas by Pipeline: Minimum Federal Safety Standards.
