# 2012 Barcelona
In order to evaluate the deformability of the whole polyethylene (PE) piping system for city-gas supply, tensile tests were conducted at the various tensile-velocities and environmental temperatures for the test specimens. They consist of commercial PE pipes and a socket-type of an electro-fusion (EF) fitting having an outer diameter of 60 mm and the SDR value of 11, which their axial fusion-bonded lengths were intentionally controlled at the target values using a masking tape. The critical fusion-bonded length in axial not to break at the fitting was calculated using the equilibrium of force based on the test results. As a result, the critical length tended to become longer as increasing tensile-velocity and as decreasing environmental temperature. It was also concluded that the PE piping system in Japan has a sufficient deformability against a typical earthquake by comparing the minimum fusion-bonded length specified in corresponding Japan industrial standard (JIS) K 6775-3 with the experimental results in this study.
Author(s) : Toshiki SHIMURA, Shinobu KAWAGUCHI Kazumi NAKAYAMA, Tomoko WATANABE, Yoshito OHTAKE
To clarify the appropriate acceleration test method and the evaluation index for it, a series of acceleration tests was conducted on commercial poly-propylene (PP) pipe for outside use. Various tests and analyses were carried out on degraded PP pipes and these results were compared with PP pipe that had actually been...
Author(s) : Nishimura, Kawaguchi, Igawa
This paper describes test methods for crosslinked polyethylene (PEX) pipes to evaluate long-term performance such as the resistance to chemical degradation due to residual chlorine at high temperature by the formation of crosslinked molecular structure and the addition of suitable antioxidants. As the methods of...
Author(s) : Nishimura, Kawaguchi
The required performance of polyethylene pipes for gas distribution is firstly described. As an evaluation method for slow crack growth, the relation between crack growth length and time under test was obtained to investigate the stress crack resistance of polyethylene pipes for gas distribution after conducting...