Collection of corrosion data from hostile and remote locations
Collection of corrosion data from hostile and remote locations
Keywords Corrosion,Monitoring, Rightrax
By combining their M1 flexible ultrasonic transducer array with a novel method of data transmission,using the cathodic protection regime of a pipeline for power, Rightrax Systems Ltd, of Warrington, reports that it can now offer a totally integrated system for monitoring and collecting corrosion data from hostile or remote locations,such as subterranean pipelines.
The M1 flexible transducer array operates at temperatures up to 110°C and comprises a thin strip of piezoelectric film, which is configured to provide 14 individual transducers per strip. Multiple M1 strips, or mats, can be easily attached to high risk quadrants of a pipeline, allowing up to 140 discrete inspection locations. It is stated that this greatly reduces inspection costs and meets requirements for accurate measurement of corrosion rates over large areas of pipework, without the need for human intervention.
Data from each of the individual ultrasonic sensors can now be transmitted to a remote, central processing location by means of an electronics module, which uses the metal structure of the pipeline as a transmission path for an electromagnetic signal. The module, the DTS 2000, allows best use to be made of the electromagnetic spectrum available on the pipeline. It uses extremely low frequency signals,with peak-to-peak voltages which sum to zero over time.
Each DTS 2000 mounted on a pipeline can monitor its local transducer array either on request from a data gathering station or against a user-defined schedule. The data packets are then transmitted to the data gathering station, where a PC, with a network interface,provides remote access, to any required location.
The power supply for the system is very small and is provided by a battery, which is recharged between transmissions by drawing a small current from the local cathodic protection (CP)potential. Consequently, all components of the system can be buried with the pipeline and there is no need for extraneous power supplies and alternative power generation facilities, such as solar panels and wind generators.
According to Rightrax the system has already been extensively proven in the field and a continuously welded, CP-coated pipeline has been shown to be a robust signal path, which will provide 100 per cent availability for the data link. For example, successful tests have been carried out using British Gas pipelines that are 30 to 40 years old, demonstrating that the technique has an expected life of the projected life of the pipeline.
The new Rightrax system,which is marketed, employed and supported worldwide by Rabco Industrial Inspection Ltd, of Poole, has application throughout the process industries and especially in the oil and gas sector, for process pipework and buried pipelines.
Further details are available from Rabco Industrial Inspection Ltd. Tel: +44(0) 1202 681971.
