Online Monitoring of Corrosion and Creep

Remote and Online Monitoring of Corrosion and Creep

DEKRA offers individual solutions to monitor corrosion and creep, preventing downtime, increasing efficiency and saving costs. To continuously monitor specific areas of your installation, we offer remote and online solutions with customer specific digital solutions.

About Remote and Online Monitoring services

We advise you in how to best collect, transport and analyze the data monitoring corrosion and creep. In our online customer portal, a wide variety of process and service data can be integrated, providing you with a fast and easy overview of all connected assets from entire systems down to single components. DEKRA has built up a long and reliable reputation offering creep measurement services worldwide, primarily within the power industry, for use in high temperature steam pipelines.

Creep Monitoring – Speckle Pattern Image Correlation Analysis (SPICA)

Speckle Pattern Image Correlation Analysis (SPICA) is used in monitoring creep strain in critical components for safety and operational reliability at weld heat-affected-zones (HAZs) and bends. Creep is often caused at bad zones in welds and in areas where external forces are exerted, for example as a result of faulty pipe support systems.

Creep monitoring can be compulsory (Pressure Equipment Authority) for safety reasons, where creep monitoring can be prerequisite for running the plant, especially at bends and headers where failure before leakage may occur.

DEKRA has been involved in digital image processing for over 25 years. One of the first applications was measuring displacements near welds (before and after welding) in fuel assembly containers to transport or store the assemblies of nuclear power plants. Noticeable savings are realized through the life extension of your assets, with creep monitoring providing an accurate measurement instead of conservative estimates. Laser (speckle) interferometry was used to accurately measure the displacements (in plane) in the area of the weld. And digital image correlation was developed using UNIX processing.

DEKRA developed the method with a highly accurate re-placement of the camera with triple triangulated spotlight projection; later updated to use a fixed, stud-welded flange with a “keyhole” into which the camera fitted. Replacement of camera accuracy must be to within 50 microns.

For safety reasons, monitoring can be compulsory to allow the plant to run (especially at risk areas where failure before leakage occurs), which is a highly effective method. DEKRA helps our customers save considerable time and money, through the reduction of inspection work during an overhaul.

Extension of inspection intervals and highly accurate life prediction allow for a considerably extended lifetime compared to relying on conservative estimates for a material’s properties. SPICA is also superior to surface replicas; as replica interpretation is subjective and ambiguous. Furthermore, due to the large number of grain boundaries, replicas are not very trustworthy for martensitic steels.

Corrosion Monitoring – Online Ultrasonic Monitoring

Whether you need to predict the remaining lifetime of an asset or closely monitor a known or anticipated corrosion area, reliable and accurate numbers are a crucial factor. Online ultrasonic monitoring provides a non-intrusive tool to gather wall thickness data and increase the accuracy and flexibility of your corrosion or erosion management. In addition to accurately determining the remaining lifetime of an asset, the increased insight gained from online ultrasonic monitoring can be leveraged to deal with greater variations in operating conditions or medium.

There are a number of advantages in online ultrasonic monitoring, including:

• Non-intrusive tools and less staff in a hazardous environment
• Reduced cost for access and preparation
• Increased accuracy of degradation rate with highly reproducible readings
• Improved responsiveness to changes in degradation

A conventional or high temperature (up to 500°C) ultrasonic wall thickness probe is installed on the asset to monitor the entirety of the asset’s service life. Alternatively, it can be installed temporarily to monitor a known corrosion or pitting area until the next planned shutdown, maintenance interval or replacement.

With a user-defined time interval the wall thickness is measured and communicated, wired or wirelessly, to the central database. This can be on DEKRA’s easily accessible cloud-based platform or integrated in your company’s environment. DEKRA is also developing services for online monitoring areas with a high risk for corrosion under insulation (CUI), for those customers interested in other non-intrusive, online monitoring tools related to corrosion.

Our remote monitoring dashboard offers the following functions:

• Integration of inspection data and other information
• Real-time overview of all connected assets
• Documentation and analysis of national regulated liabilities (logbook)