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Transmission Pipeline & Gas Distribution
Alyeska
The Atigun Pass maintenance project was a monumental job... replacing 8.5 miles of 48" main line through the rugged Brooks Mountain Range. After extensive planning, the job had to be executed with the least environmental impact, at a reasonable cost, and with minimal impact on the pipeline's throughput.
TDW performed eight 48" hot taps for installation of STOPPLE® Plugging Machines, with an average cutting time of 6.5 hours each. After the eight STOPPLE® Plugging Machines were in place on both the permanent and abandoned sides of the tie-in areas, one of TDW's designed qualification programs included the use of ultrasonic proximity probes to verify positive contact of the STOPPLE® Plugging Head with the bottom of the 48" main line.
Completion of the massive tie-in project went like clockwork. In fact, the scheduled temporary line shutdown, restart and filling procedures were accomplished in less time than had been projected.
Gas Distribution
TDW Services works daily with gas utility companies worldwide. A typical assignment was with the utilities construction division of a large city in Arizona to plug a 4" gas distribution main for maintenance.
A retired rural service line, connected to the main by a bolt-on tapping tee, had to be removed. The main provided service to several major industrial customers and could not be shut down while the service line was being removed.
TDW's SHORTSTOPP® II Plugging System, with its folding head plugger and 150 psi MWP, was utilized successfully on the job. The plugging system helped reduce costs and time, and eliminated the need for heavy-duty support equipment. The system was transported by a standard pickup truck; 3" x 4" reduced branch fittings were used, saving money and resulting in less weight on the line; and finally, far less tapping time was required.
Line pressure never wavered at the utility company's customer meters, and the repairs were made to the system and full line service was restored in four hours, less than half the anticipated time. |
