As China continues to consolidate its position as a political, economic and industrial world power, many of its large cities are experiencing the same infrastructure problems as those in other areas of the world.
And as underground infrastructure requires repair and rehabilitation, Chinese utility providers are turning to the West for solutions that permit necessary construction without major disruptions of traffic and other surface activities.
The city of Guangzhou (formerly Canton) is a center of international trade in south China with a population of more than 12 million, the third largest city in China. About 30-years ago, a gas distribution system was constructed. Originally Guangzhou used mostly manufactured gas, but has completed a transition to natural gas delivered in liquid form from Australia via ships.
During recent overlying surveys, damage to pipe coating was detected, in most instances the result of damage to coating during the installation process. This caused the depletion of the cathodic protection system over time resulting in corrosion where leaks developed.
Excavation in streets to make repairs would be costly and extremely disruptive, so utility managers and planning engineers began to research other options.
Chinese firm Wuhan Engineering and Technology Co., Ltd. is designing plans for renovating the cathodic protection system for Guangzhou Gas. The company’s president, Robert Li, had previously visited a keyholing project in northern Indiana where Miller Pipeline Corp. crews were using vacuum excavation equipment to make small diameter, precisely controlled excavations to access repair points of underground pipe. Miller has been using the technology for this type of application for more than 30 years.
Li initiated conversations with personnel at Miller Pipeline headquarters in United States, and the discussions ultimately led to an invitation to Chris Schuler, general manager of Miller’s municipal services division, to come to China and demonstrate the keyhole process to Guangzhou Gas personnel and other interested parties.
That demonstration, held on June 11, is believed to be the first use of vacuum excavation technology in China, said Schuler. Specialty tools for anode installation were provided by Miller Pipeline. Wuhan Engineering provided equipment and assisted with installation, and Schuler conducted the demonstration.
“The installation went smoothly and was exceptionally well received,” he added.
In addition Schuler had a PowerPoint presentation of the technology showing typical installations using Miller Pipeline vacuum excavation and coring equipment. Presentations were given to representatives of the engineering department of Guangzhou Gas and members of the International Science and Technology Cooperation Department, an organization responsible for evaluating technologies and granting approval for their use.
“I believe the keyholing demonstration made clear two things,” said Schuler. The process would be extremely useful in repairing the gas system’s cathodic protection system and by limiting the size of excavation required, it would significantly reduce disruption compared to conventional excavation methods.”
Schuler said the next step will be for a delegation from China to meet with Miller Pipeline personnel in the U.S. to help further their knowledge of the technology.
Coring is a specialized pavement removal process allowing Miller Pipeline crews to cut and remove a clean, intact section of concrete or asphalt covering a utility. Diameters of holes can range from 8 inches for spot hole purposes to 18 inches for full maintenance operations. The cored section is set aside and after the task is performed, the hole is filled, the core is replaced and set with non shrinking grout.
Miller Pipeline manufactures its own vacuum excavation equipment. Using high pressure air, a vacuum excavator displaces soil and can dig around buried pipe and cable with reduced risk of damage.
Miller Pipeline operates one of the world’s largest fleets of vacuum excavators. Vacuum excavation technology also is used for making gas and water service terminations, potholing to expose locations of buried utility before directional drilling, and making cast iron bell joint repairs.
Founded in 1953, the Miller Pipeline Corporation is one of the nation’s largest natural gas distribution, transmission pipeline and utility contractors, providing a comprehensive range of pipeline contracting and rehabilitation services for natural gas, liquids, water and wastewater pipelines. Specialty products and services for the industrial and telecommunication industries also are offered.
The Miller Pipeline Corp. is headquartered in Indianapolis, IN, with offices nationwide. The company maintains hundreds of crews composed of skilled, professional, highly trained employees.
FOR MORE INFO:
Miller Pipeline Corp., (800) 428-3742, www.millerpipeline.com