Millennium Projects
Technical Details
Millennium Project Number: M-2003-008
Project Title: Nondestructive Evaluation of Electofusion Lap Joints in Polyethylene Pipes Using Ultrasonic Phased-Array Technique
Project Start Date: 2003
Projected End Date: 2008
Technical Details:
Plastic pipe has been used successfully by the natual gas industry for more than three decades for applications ranging from low-pressure transmission pipelines to residential distribution lines. The standard methods for joining of polyethylene (PE) pipe brances and service tees are electrofusion (EF) and saddle fusion lap joints. While the number of saddle and EF joint failures is very low, the consequence of a gas pipeline failure can be severe. Current practice is to inspect plastic pipe joints by visual examination followed by pressure testing. Such methods are operator dependent and industry experience shows that they are subject to leaks associated mostly with joint contamination.
In Phase I, NYSEARCH requested that EWI conduct an initial evaluation of the ultrasonic phased-array (PA) technique for inspection of EF and saddle lap joints. In Phase II, EWI and NYSEARCH are continuing this program with funding from DOT/PHMSA. This two-year effort is designed to: 1) Define detection and SRE of defects, 2) Develop and optimize ultrasonic applications, and 3) Address detection limits and sizing accuracy.