Hawkeye-2000 vs Magnetic Particle & Dye Penetrant Methods
A major Pulp and Paper Mill in the Southern Michigan area needed a Deaerator Tank inspected during their summer outage per insurance company requirements. Because of manpower and budget constraints, the mill sought to avoid the grit blast surface preparation that was necessary for Magnetic Particle and Dye Penetrant Inspections.
The customer’s goal was to have the seam and attachment welds in the tank inspected in one shift with minimal cleaning. Plant personnel wanted the inspection crew to stay onsite while identified defects were repaired, and then retest these repaired areas during the same shift.
The tank specifications were 7.5’ Diameter x 18’ in Length, 0.375” thick Carbon Steel.
TesTex, Inc. has developed the HAWK-EYE 2000 weld scanning system for crack detection. The system is based on the principles of electromagnetics and can replace the old laborious techniques such as vacuum box, dye penetrant or magnetic particle inspection. Unlike UT, MT, or DP, the system does not require a bare metal surface and is forgiving to scale, corrosion products, etc. With scanning speeds up to 1 ft./second, the system is fast, accurate and cost effective for the evaluation of cracks in welds.
After the tank had been drained and dried, only some light wire brushing in a couple of areas was required. The test consisted of approximately 400 linear feet of seam and attachment welds. All accessible welds were tested with the Hawkeye and UT readings for shell thickness were taken to round out the inspection and satisfy the insurance requirements.
During the test, 6 areas of cracking were identified. The areas were repaired and then reinspected. The Hawkeye 2000 Inspection was completed in one shift. This allowed the plant to focus on other pressing issues during the outage.