Remote monitoring systems for CP
Remote monitoring systems for CP
Keywords Cathodic protection, Gas, Pipes, Tanks
The US Army Corps of Engineers operates and maintains underground gas, water, and heat distribution pipelines; underground storage tanks; and water storage tanks across the USA. Much of this work involves monitoring the cathodic protection (CP) systems that protect these facilities against corrosion. Over the years, Army Directorates of Public Works (DPWs) have employed traditional, labour-intensive CP evaluations,which require the technicians to travel to each structure and perform a series of measurements with a portable multimeter. A lack of manpower and the high expense of these time-consuming evaluations have made it increasingly difficult for the DPWs to conduct regular, periodic tests to maintain the CP systems effectively.
The Army Construction Engineering Research Laboratories (CERL) is now testing several automated devices currently on the market that can eliminate or greatly reduce the need for manual CP testing. These devices allow technicians to monitor and control CP equipment remotely via a central computer. When a problem is detected at a rectifier or a structure-to-soil potential test station, the system alerts maintenance personnel so they can make the required repairs.
The project involves installing remote monitoring devices in the field and comparing their output with measurements conducted by traditional methods. So far, CERL has tested equipment from three manufacturers on a CP system that protects a high-temperature hot-water distribution system in Fort Drum, New York. Remote monitoring equipment from three more manufacturers will be tested before the end of the year.
CERL researchers expect the demonstrations to show that the cost and manpower required for proper CP system testing can be reduced significantly. Using traditional methods, an annual potential survey on an average mile of pipe costs about $600 to $1,000. In addition, each rectifier must be checked monthly. Computerized equipment cannot only reduce inspection costs, but can continuously monitor CP systems to ensure proper operation. According to CERL, it costs $1.3 to $1.6 million to replace one mile of the type of underground heat distribution piping being used in this study. This does not include the cost of energy losses that occur when an unprotected system is leaking.
For further details contact Vicki Van Blaricum, CERL, Attn: CECER-FL-M, PO. Box 9005, Champaign,Illinois 61826-9005, USA. Phone: +1 217 373 6771.
