VertiScan

Boilers suffer from many forms of degradation while in service. Water Wall tubes can suffer from Hydrogen Damage, pitting, ash and soot-blower erosion, graphitization, under-deposit corrosion, thermal fatigue cracking and creep damage. All of these defects can be detected by use of a fast robotic system known as VertiScan

The VertiScan System is used to rapidly scan the water walls of a boiler during an outage so that repair decisions can be made proactively.

Up to five tubes are scanned at once, at speeds up to 5 m (15′)/min The robotic (TubeCAT) crawler can climb 100′ up/down the water wall and handle up to 1/4″ of scale between the tubes.

Results are presented immediately on a colour map showing areas of degradation. The cost to scan all four walls of a boiler is generally far below the cost of an emergency shut-down due to a tube failure.

All indications found are checked with visual and ultrasonic techniques where tubes are accessible.

• Hydrogen Damage
• Fishmouth failure cause by Hydrogen damage
• Blisters and pinhole leaks
• Local Ash erosion
• Thermal Fatigue Cracking
• Internal Graphitization (under-scale pitting)
• Internal pitting at weld