Waveform Controlled Welding in ASME Section IX

Metallic pipe is produced to meet API, ISO or other industry specifications. When the manufacturing process involves welding of a longitudinal or spiral seam, the welding is typically done to the standards of ASME Section IX. Girth welding of pipe is often performed using ASME Section IX standards and pulsing waveforms. In 2006, a task group was set up in ASME Section IX to explore waveform controlled welding and recommend code changes. The recommendations were submitted for approval, and the resulting code changes were published in the 2010 edition of ASME Section IX. The changes deal with the way energy or power is measured and the resulting calculation of heat input. This paper will explore differences in the measurement and calculation methods when using waveform controlled welding and discuss why these occur. The code changes will be presented. Detailed explanations will be given of how to comply with the new standards using either new or existing procedure qualifications.