RESP - Robot for the External Servicing of Pipes
Description
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Cutting off service connected to a cast iron or steel main is one of the most common operations performed by gas distribution maintenance crews. This procedure involves squeezing off the steel service pipe in order to prevent significant gas leakage during the disconnection procedure, cutting the service pipe off, removing the service tee from the threaded hole in the main, and replacing it with a plug. A technician requires a minimum of a two-by-six foot excavation in order to perform such routine procedures on underground pipes. These operations are often performed in urban areas where the cost of pavement restoration is considerable.
The aforementioned construction and maintenance procedures can be accomplished at considerably lower costs using “keyhole technology”. This method uses a novel excavation procedure which improves operation efficiency by using a small circular hole for common service operations. Procedures, such as cutting off service to a cast iron or steel main, can be done with minimal labour and restoration costs by integrating remotely operated, keyhole compatible robotic systems into the operation.
Engineering Services Inc. (ESI) is dedicated to the development of various keyhole technology compatible tools including service cut-off and service connection tools. ESI has developed two remotely operated tools: a high performance squeeze-off tool and a vertical cutter. So far, three complete service cut-off sets have been developed: one for cast iron mains, one for steel mains, and one for plastic mains. The tools have been used in the field for routine, as well as emergency, cut-off. Limited production of a complete tool set is planned for the near future.
Another common operation is cutting off services and removal of service tees from medium pressure (approximately 60 PSI - 4 bar) steel mains. Due to higher gas pressure, a different procedure is required from that used on low pressure mains. The hole in the main has to be plugged and the top part of the tee has to be cut and removed so that only a short nipple remains attached to the main. The gas must not escape from the main during the disconnection procedure. A complete set of tools for this operation has recently been developed by ESI. The set includes a gripper, a sealing tool, a horizontal cutter and a cap applicator. Limited production of a complete tool set is planned.
A set of tools has been also developed for 1/2 inch plastic pipe cut-off and reinstatement operations. The set includes four tools: a gripper/squeeze-off tool, a cutting tool, a scraping tool, and an electro-fusion fitting holder.
Features
- Keyhole technology tools are operated through a 46 cm (18 inch) diameter circular hole
- Tools are remotely controlled from above ground to a depth of 1.8 metre (6 feet) below ground level
- Tools can be adapted to various diameters; they were manufactured to handle steel, iron and plastic pipes from a 1.5 cm to 10 cm (1/2 inch to 4 inch) diameter
- Standard 100 PSI (7 bar) compressed air is the only power source required
- Compressed air and high pressure hydraulics are used to activate the tools
- Tools are activated from the ground level by a single operator using foot switches
- Tool handles can be adjusted for different operators.