English Abstract

Long-term Reliability Evaluation of the Diaphragm for Gas Meters

Yoshinori OZAWA *1
Hideki YAMAGUCHI *1
Akiharu ASADA *1
Hiroyuki NISHIMURA *2
*1:OSAKA GAS CO., LTD., Konohana-ku, Osaka, Japan
*2:Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan
Nippon Gomu Kyokaishi,(2013),86(7),227-233 Original Paper in Japanese

To establish a technique for reproducible instrumental error variation on the plus side of diaphragm gas meters, diaphragms collected from the field were examined so as to determine the major cause of instrumental error variation on the plus side. The authors then carried out tests to reproduce instrumental error variation on the plus side, studying the conditions for a test of accelerated degradation equivalent to 20-year use. As a result, the authors found that the major cause of instrumental error variation on the plus side is diaphragm thermal degradation. The authors also confirmed that the accelerated heat aging conditions that replicate the state of a diaphragm after 20-years' use are 2000 hours at 70ºC and 6000 hours at 60ºC.

Keywords: Gas meter, diaphragm, rubber, reliability, accelerated degradation test, Arrhenius plot