FIBER GLASS REINFORCEMENT WRAP GETS DOT NOD FOR GAS-LINE USE

Panhandle Eastern Corp.'s Texas Eastern Transmission Corp. has become the first U.S. natural-gas pipeline company to install, under federal waiver, a fiber glass reinforcement on an in-service gas pipeline. The Clock Spring repair system was installed in August on six segments of Texas Eastern's 20-in. gas pipeline in Fayette County, Ohio, after the company had received a U.S. Department of Transportation (DOT) waiver to use the system in place of conventional DOT-mandated repair

Dec. 13, 1993

2 min read

The Clock Spring repair system was installed in August on six segments of Texas Eastern's 20-in. gas pipeline in Fayette County, Ohio, after the company had received a U.S. Department of Transportation (DOT) waiver to use the system in place of conventional DOT-mandated repair methods.

CONVENTIONAL METHODS

DOT is the federal agency responsible for the overall safety of interstate natural-gas pipelines.

The two DOT-mandated methods of transmission-pipeline repair are replacement of pipeline segments or welding of steel sleeves over suspicious areas.

A DOT waiver of these conventional methods was necessary to demonstrate the in-service performance of this reinforcement technology.

Texas Eastern will report performance results to DOT in 2 years with follow-up examinations after 4 and 8 years. The company has stated that existing research indicates that this reinforcement technology fully restores the pipeline's originally designed margin of safety.

The first 2 years' results will provide additional information which could support an industry waiver or a petition to change the current DOT rule (49 CFR 192.713 (a)) permitting the use of composites as a permanent repair method.

Panhandle Eastern and the Gas Research Institute (GRI), Chicago, are providing support funding for installation of Clock Spring technology, and the GRI is monitoring the results.

LESS COSTLY

Once the necessary excavation is completed, repairs using the reinforcement material can be made in a few hours by two people without the need for welding, cutting, or special handling equipment.

Texas Eastern says the cost is significantly less than for conventional replacement methods.

The 12-in. wide reinforcement wraps consist of glass fibers impregnated with a polymer-based resin that, when treated with a special adhesive and wrapped around the weakened area of a steel pipe, restore the pipe's integrity (Fig. 1).

The reinforcement technology has been used to repair steel pipelines transporting liquid products since 1992.

Clock Spring is manufactured by Clock Spring Co. L.P., Long Beach, and is delivered to the installation site wound as a cylinder, much like a clock's spring. It can be unwound for application while retaining its original shape.