Introduction 3
The object under analysis is situated at the center of this technique, either on the
surface or in volume, in order to find disparities or anomalies. We use a transmitter
or source to “illuminate” the object, which for sonar may be the noise emitted by the
ship itself and a hydrophone receiver. In the simplest case, this being visual
examination, the source is light and the receiver the eye. Information resulting from
this examination provides an indicator that can be used for diagnosis.
1.2. Industrial development of NDE
1.2.1. Pressure equipment
Industries and railways have been developed with the use of steam engines ever
since the mid 19th Century. The increasing number of accidents related to the use of
steam, of which pressure, volume and temperature increase regularly, led States to
implement legislation in order to regulate pressurized steam equipment by any means
possible. In France, legislation was implemented in October 1907, before publication
of the ministerial circular of 26th January 1926, concerning “steam equipment for the
preparation of coffee and cooking food”, followed by the broader decree of April 2nd
1926. It included a deterministic approach based on the laws of physics (Gay Lussac)
and mechanics, more specifically resistance to rupture or fatigue, supported by
ten-year hydraulic testing during which a visual examination of all equipment was
carried out. It was in force until the European Directive 97/23-CE and decree 99-1046
of 13th December 1999 were transposed into French law. Since its implementation in
1926, the regulatory framework has become enriched by feedback accumulated over the
years, resulting in legislation such as the decree of January 18th 1943 for gas pressure
devices, for example. In practical terms, this concerned refineries, industrial chemical or
tire-making plants, steel-making, pipelines, etc.
The decree of 26th February 1974 dealt more specifically with “nuclear boilers”;
it was updated and replaced by the decree of November 10th 1999, after publication
of the European directive. Addendums relating to the roles of actors were introduced
via the Energy Transition for Green Growth Act on August 17th, 2015 (France). In
terms of pressure equipment monitoring, the most effective measures used to
examine all components (tanks and their welds, pipes, valve bodies, etc.) were
integrated into legal texts by Parliament. To meet these requirements, the industry
came together to develop codes and standards not only for the design, construction
and operation of steam or gas pressure equipment, but also for non-destructive
testing of this equipment prior to market entry, followed by monitoring of them
when in operation. More than 130 general standards [AFN 14a] were validated at the
end of 2014 at European level, relating to visual, ultrasonic, Eddy current, magnetic
particle inspection, bleedout, X-ray, gamma radiography, stress-strain measurement,
infrared thermography, acoustic emission, and sealing methods as well as those