Corrosion Monitoring
Problems resulting from inadequate water treatment often escape detection through routine monitoring. The consequences of corrosion are not immediate; however, corrosion is irreversible and uncontrolled corrosion can have a catastrophic effect on system reliability. AWTC’s water treatment professionals will work to ensure that the facility operators and the water treatment vendor work together to maximize the life of critical equipment.
The continual corrosion monitoring program includes:
- Tracking & Trending Corrosion Product Concentrations
- Internal Equipment Inspections
- Corrosion Coupon Evaluations
- Spool Piece Inspections & Analyses
- Destructive Pipe Sample Evaluations
- Corrosion Rate Determination via Ultrasonic Thickness (UT) Gauging
- Real-Time Corrosion Rate Monitoring via UT test templates
Ultrasonic Testing and Templates
Wall thickness measurements available from Ultrasonic thickness (UT) gauging can be used to determine corrosion rates more accurately than corrosion coupons when measurements are made at permanently installed UT test templates. When test templates are installed, actual wall loss is measured from the same site over time, allowing for more precise estimates of corrosion rates that approximate real-time rates. Test templates are an effective way to determine the remaining useful life (RUL) of system piping without the need for destructive analysis.
ltrasonic testing can be performed without the need to drain the system. It can cover a large portion of a piping system economically and can be used to determine the presence and extent of localized corrosion. However, UT does not provide information regarding the presence or composition of waterside deposits. Waterside deposits are best evaluated by visual inspection and destructive pipe sample analysis.
NON-DESTRUCTIVE PIPE ANALYSIS
Non-destructive techniques, including ultrasonic testing and borescopic inspections, are valuable tools for establishing existing conditions and estimating corrosion rates.
DESTRUCTIVE PIPE ANALYSIS
Destructive analysis involves removing a section of system piping for evaluation in AWTC’s in-house shop and laboratory. AWTC evaluates the pipe metallurgy and surface conditions using physical and chemical analytical techniques in order to identify modes of corrosion and estimate corrosion rates. AWTC has the experience to put the analytical findings in the context of the service history and operating conditions of the system. AWTC’s analysis includes photo-documentation of the samples in pre- and post-analysis conditions.
Destructive analysis provides the most comprehensive information regarding a pipe sample and is often used as part of a due-diligence and MEP reviews.
Forensic Pipe Analysis
Heat-transfer equipment and piping can fail for reasons that are not always obvious. In cases where corrosion or fouling is suspected, AWTC’s water treatment professionals can investigate the problem using forensic pipe analysis. Forensic pipe analysis is also used to determine existing conditions within a system and estimate the remaining useful life of system piping.
Using the results of the destructive and/or non-destructive tests, AWTC can work with the water treatment vendor and plant personnel to benchmark existing conditions, remedy conditions contributing to failures and/or accelerated corrosion and provide recommendations for continued protection of the system.
