New Keyhole Pipeline Inspection Camera Available: System for Small-Hole Use in ‘Live’ Conditions

A new camera system that accesses pipes through 18-inch-diameter surface "keyholes" is capable of examining pipe conditions while gas is flowing and conducting inspections without interrupting service to customers.

Now available from ULC Robotics as the PRX250K Keyhole Camera, the system enhances gas-infrastructure safety by providing a lower-cost option to internally inspect gas pipes. It is small and flexible, making it easily maneuverable through tight bends, allowing utilities to examine pipe segments without the need to drill additional access holes for hard-to-reach locations.

The system provides visual pipe inspections, measures distance of travel, and allows the operator to map the precise locations of joints and fittings observed on the monitor. In the field, the camera can capture footage in three different ways—on the hard drive of the unit, on magnetic tape, or on a CD.

The technology was developed under the sponsorship of Operations Technology Development (OTD), a not-for-profit company that supports a wide variety of gas-operations-related research and development activities for the benefit of the gas industry and its customers. Gas Technology Institute (GTI) managed the project and coordinated field-demonstration activities in 2006 in Consolidated Edison Company’s service territory in New York City.

"Because of the reduced excavation and restoration needs, most maintenance activities conducted through keyholes can be completed at half the cost of those conducted with conventional excavations and trenches," explains Dennis Jarnecke, who manages keyhole-related research at GTI. "While there have been pipe-inspection cameras available for years, the industry saw the need for a camera that could be used through keyholes—and used without having to shut off services or build a bypass."

The key part of the project involved linking a commercial camera system from ULC Robotics with a specially designed vertical pipe-access system from AHL Systems, Inc. The camera is lowered through a vertical launch tube, and then negotiates a 90-degree angle to proceed horizontally through the pipe.

The keyhole camera is rated for use up to 60 psig and can be used to inspect 4-inch- to 12-inch-diameter cast-iron, steel, or polyethylene (PE) pipe. In cast-iron and steel pipe, the camera travels an average of 150 feet travel in each direction from the launch point, providing 300 feet of pipe inspected from one pit. In PE pipe, travel distances average approximately 250 feet in each direction (500 feet total pipe inspected from one pit). Travel distances will vary based on pipe size, pipe material, condition/cleanliness, and the pitch of the pipe.

ULC Robotics (Deer Park, NY) provides an inspection service that uses the camera and also offers the camera system for purchase. PECO Energy in Philadelphia was the first company to purchase the new keyhole pipeline inspection robotic camera system from ULC Robotics.

"We followed the project all along its development, and we were especially impressed with the field demonstration," says PECO's Mark Andraka, Senior Engineer. "At PECO, we feel that being able to cost effectively inspect inside our live gas mains will not only enhance the investigation of water intrusion and rehabilitation issues, but efficiently help expand the keyhole process. This camera system can help aid in the precise location of critical areas. We see this camera system joining a host of new technologies to help in our efforts to maintain the safety, reliability, and cost effectiveness of our infrastructure."