ILI Retrofit Design Project

GTS has extensive experience with in-line inspection projects through the entirety of the ILI retrofit and inspection process. In support of client’s retrofit programs, GTS engineers reviewed the pipeline system to:

• Evaluate hydraulic feasibility of runs
• Select launcher/receiver locations
• Perform detailed scoping to establish the work required to make a run piggable
• Create detailed upgrade design packages for replacements, hydrotests, regulator stations, valve lots, and launchers and receivers
• Provide construction and as-built support
• Coordinate with tool vendors for tool selection and risk mitigation
• Support inspection run execution
• Analyze ILI tool data

GTS provided the detailed scoping and engineering design for the ILI retrofit of over thirty miles of transmission pipeline. The run was designed to be completed in two sections. The scope included:

• Scoping and design of a 12” launcher and receiver
• Scoping and design of a 16” launcher and receiver
• Providing engineering and design services for the ILI upgrades required to run the selected ILI tools, as well as hydrostatically testing twenty-five miles of the pipeline due to lack of traceable, verifiable, and complete test records
• Collaborating with permitting (environmental and ministerial), land planning, construction contractors, gas system planning, owner’s engineers, and other project stakeholders to ensure that the project was executed efficiently and on time

During the scoping of the 12” run, GTS identified that it was common for construction to utilize miter bends during the 1950’s installation of the line. Unfortunately, the records did not confirm the quantity nor location of the miters installed on the line. GTS collaborated with the ILI tool vendor to determine that utilizing a 10”x12” multi-diameter tool would allow for the additional flexibility necessary to pass through the unknown miters. This approach resulted in eliminating at least six retrofit locations.