Flexible pipes are made up of several different layers specifically designed to meet the requirements of our clients and API17J / ISO13628-2. In the pursuit of ever more efficient and reliable solutions, even in the world’s harshest and deepest offshore environments, TECHNIP’s R&D activity is focused on extending its product range by introducing new products and materials. As part of this innovation program, new polymers are constantly being investigated to assess their potential as a pressure sheath.
The pressure sheath is the most critical thermoplastic sheath within the structure. Its role is to contain internal fluid and transfer internal pressure to the pressure vault layer outside it. To fulfill that mission, this polymer must be leakproof and perform over wide temperature and pressure range. In operation condition, the presence of small flaws within the pressure sheath could propagate leading to failure and significant environmental and operational damages. Therefore, the manufacturing of such a polymer layer must conform with ever-higher levels of reliability and quality. This is the reason why a visual inspection of pressure sheath according to API17J / ISO13628-2 standards is mandatory.
As a leitmotiv, TECHNIP dedicates a lot of effort, not only to extend the limits of the possible by introducing new materials, but also to take inspection further beyond standard requirements by developing dedicated on-line NDT control systems able to ensure layer high quality. Many people are familiar with the medical applications of ultrasonic imaging in which ultrasonic waves are used to create highly detailed cross-sectional pictures of internal organ. Medical echography is commonly performed with specialized multielement probe known as phased-array and their accompanying hardware and software. The applications of ultrasonic phased-array technology are not limited to medical diagnosis and in recent years, increasing use of these systems can be observed in industrial environment. Nevertheless, although phased-array systems on the market can provide new levels of information and visualization, they are manually and locally operated and are inappropriate to control polymer sheath over several kilometers during manufacturing.
This paper presents a specific and automated ultrasonic system dedicated to manufacturing control of thermoplastics such as the pressure sheath. Developed by TECHNIP, and based on cutting edge ultrasonic technology used in aerospace and medicine, OPUS is a world-class NDT system able to prove that our pressure sheaths meet design criteria and achieve the highest quality level.
