The Gas Research Institute, Chicago, and Gaz de France, Paris, are cosponsoring a $580,000 program to adapt magnetic flux leakage (MFL) technology for inspection of in-service gas distribution mains.
The organizations lead natural-gas research and development in the U.S. and France, respectively. They plan to field test a prototype MFL inspection system in 1997, with commercial product and service introduction in 1998.
Tubescope Vetco International Inc. and Guided Boring Systems Inc., both of Houston, will design, fabricate, and test the system. Previously, Vetco has supplied MFL systems for large-diameter, high-pressure pipelines.
GRI says there are nearly 600,000 miles of small-diameter, steel gas mains operating in the U.S. alone. Adapting MFL in-line inspection systems will enable gas-distribution companies to benefit from a technology widely used by larger-diameter transmission pipelines to detect metal loss
GRI says that a new MFL tool inspecting in-service mains increases pipe safety and reliability, lowers operating costs, and minimizes service disruptions.
MFL technology employs magnets and sensors to travel through a pipe while gas is flowing. The magnets produce a magnetic flux (or field) in the pipe wall, and sensors measure the leakage (changes in the magnetic field) at zones where the pipe wall thickness is not uniform.
Data analysis of leakage strength determines the severity of metal loss.
Among the features of the MFL system being developed are the following:
Gaz de France is a fully integrated company that stores, transports, and distributes natural gas in France. GRI manages a cooperative research, development, and commercialization program for the mutual benefit of the natural gas industry and its customers. GRI works with research organizations and manufacturers to develop gas technologies and to transfer new
products and information to the marketplace.
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