TPT March 2007

I nspection, M easuring, T esting & M arking

The specimen has one or more artificial flaws introduced into it. These flaws are as simple as a hole or can be an intricate series of notches on both the inside diameter and outside diameter of the pipe. The specimen can be as small as a few inches of pipe cut from the production run to a full length pipe. The process that meets the requirements to make the artificial flaws is known as EDM (electric discharge machining), while the process is also referred to as metal erosion. Scan Systems Corporation (USA) has been making calibration standards for over 20 years. The company creates the standards at its Houston, Texas facility with EDM or conventional machining, and ships material worldwide. In addition, the company manufactures and market the EDM Notch Master used in pipe mills, the same unit used at its own facility.

Calibration specimens vital to all inspection processes

Now, more than ever, the inspection process is being included as a part of production rather than an added service. The end result is that mills provide pipe inspected to API (American Petroleum Institute) or ISO (International Standards Organization) published standards before shipping.

These pipe producers are investing millions of dollars in a variety of inspection techniques such as UT (ultrasonic testing), EMI (electromagnetic inspection), and EC (eddy current). Speed and accuracy are the important qualifications for the test equipment. The common

element in the three methods is the need to calibrate the inspection equipment. A requirement in the calibration process is nearly always the use of a calibration specimen. Also referred to as test blocks, cal blocks, coupons, and cal standards, the specimen is a sample of the same (or near same) metal as that being inspected.

fi A calibration specimen is used in all three main inspection techniques

Scan Systems – USA Fax : +1 281 219 2317

Email : davids@scansystems.com Website : www.scansystems.com

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