The traditional method of inspecting boiler water wall tubes for loss of wall thickness is by taking many thousands of ultrasonic thickness readings spaced several feet apart in elevation. In order to do this the boiler must be scaffolded and the tubes usually cleaned to bare metal where the ultrasonic thickness readings are to be taken. Now we can offer a time and cost saving alternative with VertiScan. The Vertiscan is an inspection head used with a crawler, designed to allow inspection of fives tubes at the same time. Utilizing an adapted Remote Field Eddy Current Technology.
How it Works:
The inspection method is an adapted RFT (Remote Field Technology) method which is a low frequency AC (electromagnetic) technique similar to remote field eddy current. In this technique a signal is sent from an exciter coil(s) to 15 detector coils.
The signal passes through the tube wall at the crown of the tube near the exciter(s) and returns through the wall again near the detectors. The time of flight of this signal is directly related to the wall thickness of the tube near both the exciter(s) and detectors.
• Electromagnetic flaw detection for water wall tubes of boilers
• 2 parts: Tube Cat (crawler) and VertiScan (equipment)
• Uses adapted Remote Field Technology
• Detection of metal loss, pitting, fatigue cracks, hydrogen damage
• Allows for 5 tubes to be tested at the same time
• 1.5 up to 3m/min; 6000 point readings/ meter
• Detects defects from 5% wall loss
• 15 detector coils