Delivery Reliability for Natural Gas--Inspection Technologies

Abstract

The Remote Field Eddy Current (RFEC) technique is ideal for inspecting unpiggable pipelines because all of its components can be made smaller than the diameter of the pipe to be inspected. For these reasons, RFEC was selected as a technology to be integrated with the Explorer II robotic platform for unpiggable pipeline inspections. The research work is a continuation of a prior DOE-NETL project but is now directed towards a seamless integration with the robot. The laboratory set-up has been improved and data collection is nearly autonomous. With the improved collections speeds, GTI has been able to test more variables. Tests have been run on 6-inch and 12-inch seamless and seam-welded pipes. Testing on the 6-inch pipes have included using five exciter coils, each of a different geometry. Two types of sensor coils have been tested. With a focus on preparing the technology for use on the Explorer II, improvements in power consumption have proved successful. Tests with metal components have been performed to check for interference with the electromagnetic field. The results of these tests indicate RFEC will produce quality inspections while on the robot. GTI has also been testing manufactured detection boards currently used for boiler tube inspections. These boards are appropriately compact for use on the Explorer II robot and are able to detect defects at the speed of robot travel. In addition to advanced sensor development, GTI has participated in sensor/platform definition and module design activities. Mechanical constraints, power requirements, limited control and communication protocols, and potential busses and connectors have been addressed. GTI has conducted a proper design process to produce a sound design for the RFEC components to fit into two modules. The remaining work to be performed in the design of the sensor module is packaging and strengthening.