Intrinsically safe acoustic emission equipment opens the door to permanent monitoring applications in the oil and gas industry

摘要

The oil and gas industry is a very prospective target group for the permanent installation of acoustic emission (AE) instrumentation for monitoring various test objects for crack growth or active corrosion. According to directives and standards, electrical instrumentation installed in a potentially explosive atmosphere must be certified intrinsically safe. The development and certification process of intrinsically safe instrumentation needs great effort, which is not economical for the relatively small market for intrinsically safe AE instrumentation, nowadays. On the other hand, the non-availability of suitable intrinsically safe AE instrumentation could be a hindrance for the potential market growth. European Commission helps to overcome the problem: In the European research project titled "Cost effective corrosion and fatigue monitoring for transport products (CORFAT)" (www.corfat.eu), the German company Vallen Systeme GmbH is responsible for developing an intrinsically safe AE sensor system (ISAFE3). The ISAFE3 system is employed for detection of corrosion and fatigue crack of storage tanks used in surface transportation means like ships, mainly oil tankers, trucks and rail wagons. ISAFE3 is intended to be ATEX certified for use in most dangerous explosion zone 0 (where an explosive atmosphere can permanently be present) and for gas group IIC (where lowest spark energy can ignite an explosion). The sensor system must be sealed for immersion into oil at peak pressure up to 12 bar (caused by sloshing forces in an oil tanker ship). This paper presents basics about the requirements of the applicable standards and the applications and an overview of the realization of ISAFE3.