A study of rapid crack propagation in gas-pressurized PE pipes [PE]

Author(s) : Hirofumi Kyutoku, Kazuhisa Igawa, Hidekazu Honma, Sakiko Fukunishi, Hiroyuki Nishimura 2018 Las-Vegas

There are mainly two grades of polyethylene pipes for hot water supply and heating. The excellent molecular structure polyethylene resins having resistance to stress crack growth are used because hot water is flowed for a long time in both polyethylene pipes. Furthermore, various additives are mixed to prevent the...

Author(s) : Takehiro Fujii, Kazuhisa Igawa, Hidekazu Honma, Kazushi Yamada, Hiroyuki Nishimura 2016 Berlin

The hydrostatic stress rupture test has been conventionally conducted as a good method of the lifetime evaluation. The hot water circulation test which is reflected to the actual operating condition is also useful method. The correlations and differences between the two tests were examined. Compared with the...

Author(s) : Yuji Higuchi, Rei Hyuga, Kazushi Yamada, Hiroyuki Nishimura 2016 Berlin

Recently, thermoplastic-based composite pipes have been developed in order to satisfy the higher requirements for gas and water distribution. Although the stress rupture test is now the major test method used to evaluate the long-term performance of these pipes, developing a new, convenient test method making it...

Author(s) : Yuichiro Goto, Hiroyuki Nishimura 2016 Berlin

The damage of PVC pipes caused by the great earthquakes was investigated in Japan by various organizations including public and private institutions. As a result of these investigations it is found that high-impact modified PVC pipes with the long insertion length have the least failures. Moreover it is also reported...

Author(s) : Takehiro Fujii, Hideo Hirabayashi, Kazushi Yamada, Hiroyuki Nishimura 2016 Berlin

It is important to stabilize the scraped surface of the polyethylene pipe, even if some operator scrape the surface of the polyethylene pipe. In Japan this automatic saddle scraper is widely used for improving workability and plumbing quality The newly developed “Automatic saddle scraper” consists of the casing...

Author(s) : Kazuhisa Igawa, Yuji Higuchi, Daisuke Tanemura, Kazushi Yamada, Hiroyuki Nishimura, Sakiko Fukunishi, Kazufumi Kohno, Hidekazu Honma, Hidekazu Sugimori 2014 Chicago

Recently, as awareness about energy-saving is increasing, high-efficiency energy systems have been developed and introduced. In addition, public and private sectors have simultaneously been implementing various efforts aiming to improve their prevalence rates. These initiatives are represented by the Cogeneration Gas...

Author(s) : Yuji Higuchi, Tomohiro Tanishita, Kazushi Yamada, Hiroyuki Nishimura 2014 Chicago

Recently, PE resin-back composite pipes have been developed in order to satisfy the higher requirements for gas and water distribution. Although the stress rupture test is now the major test method used to evaluate the long-term performance of these pipes, developing a new, convenient test method making it possible to...

Author(s) : Kazuhisa Igawa, Yuji Higuchi, Akio Kamatani, Kazushi Yamada, Hiroyuki Nishimura 2014 Chicago

The polymer electrolyte fuel cells (PEFC) cogeneration system has been commercialized in Japan. The number of commercialized PEFC residential cogeneration systems have reached 100, 000 in total at the end of last year. The waste heat can be used for hot water supply and central heating. Hot water distribution pipes...

Author(s) : Nishimura Hiroyuki 2012 Barcelona

The effect of antioxidants of polyethylene of raised temperature resistance (PE-RT) pipes for a long lifetime for hot water supply and for space heating was evaluated in this paper. Some polyethylene specimens mixed with different amount of antioxidants such as hindered phenol and hindered amine were prepared by...

Author(s) : Yuji Higuchi, Masaaki Ishikawa, Toshiaki Furuno, Eiji Okamura, Masahiro Mutoh, Hiroyuki Nishimura, Asami Nakai, Hiroyuki Hamada 2012 Barcelona

Pipe materials that are resistant to damage by thirty-party works were investigated with attention to materials already used for other purposes. Pipes for underwater cables, water service and agricultural use, both multiple-layer and single-layer types, were selected for the test. Protective materials were also...