Juseok OHa, Youngjin Ohb, Seunggun Leeb, Jongsung Kimc, and Sunwoong Choia
Papers # 2012 Barcelona
Butt fusion welding is a method of joining often practiced in structural plastic pipes used in pressure applications, where joint integrity is a strict requirement for design lifetime of fifty or more years. The fusion process encompasses melt flow and rheology as well as diffusion and solidification sciences in which they all work toward in producing a safe and reliable joint. Different joining conditions were prepared to investigate welding property. Among several welding conditions, this paper focuses on the effect of pressure and temperature of welding process to slow crack growth. From short term test, it was revealed that welding pressure and temperature exert considerable effect to the joint strength. Besides short term test we designed and conducted long term integrity tests, and these experiments will reveal more profound effect of welding conditions.
Author(s) : Jörg Wermelinger, Sunwoong Choi
In the development of an international standard on non-destructive test for polyethylene electrofusion socket (EF) joints, the inspection capability of the phased array ultrasonic test (PAUT) in assessing flaws in the joints was needed to establish procedure qualification of the test method. For this, a worldwide...
Author(s) : Sunwoong Choi, Tom Marti
Small scale, steady state (S4) testing per ISO 13477 is a lab-based procedure to determine the critical pressure at which a fracture will propagate following initiation in a given pipe material filled with a given test medium. The S4 test was originally developed for the natural gas industry using air as the test...
Author(s) : Sooho Pyo, Junghyun Nam, Yoonsang Kim and Sunwoong Choi
The Notched Ring Test (NRT) has been recently developed to measure slow crack growth (SCG) in plastics pipes and fittings. The NRT specimen in the form of a notched full ring is directly obtained from the extruded pipe or injection molded fitting and has demonstrated its effectiveness in generating slow crack growth...