Estimation of surface void initiation of polyethylene pipes immersed in chlorinated water [PE]

Author(s) : Mitsuaki TOKIYOSHI, Gentaro TAKAHARA, Joji HINOBAYASHI, Toshinori KAWABATA, Takashi KURIYAMA

Glass fiber reinforced polyethylene pipes and fittings are controlled for bending characteristics (Strength and stiffness) for vertical and axial directions of pipe by spiral cross winding method. Generally, to use this method, it takes much stronger for vertical strength than axials cause of extruded direction,...

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

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

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

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

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

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) : Mitsuaki Tokiyoshi, Philippe Vanspeybroeck, Kensei Inoue, Stephan Fullgrabe, Takashi Kuriyama, Toshinori Kawabata, Joji Hinobayashi

Big diameter polyethylene pipes used an important role due to superior performance (Flexibility, light weight, long lifetime and tighten joint) for water and industrial supply to several countries. However according to standard concerned Polyethylene pipes as like ISO4427 we are being used solid wall pipe with too...

Author(s) : Tomoyuki Kobayashi, Shigeru Ogasawara, Satoshi Nishijima, Hiroki Ohzeki, Shinichi Nishiyama

In this paper, it is reported the development and product design of CIPP with Biomass resin, “Furan resin”. To satisfy the both properties of Long Pot-life and enough curing speed of resin as the application of CIPP, latest hardener of acid catalyst was very effective to achieve the both properties shown above....

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

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

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

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

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

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...

Author(s) : Asami Nakai, Yoshitaka Tanaka, Akio Ohtani, Shigeyoshi Matsubara, Louis Laberge Lebel, Hiroyuki Hamada

Pultrusion process is one of the composite production methods that have been used for mass production of uniform profiles. However, there are two problems that are commonly found in pultrusion products; one of which is its anisotropic mechanical properties. This anisotropicity stems from the alignment...

Author(s) : Takashi KURIYAMA and Norio HIMUKAI

In order to make clear the reliability of PVC-U recycled pipes in relation to the three-layer structure, we described the deformation and fracture mechanism of wall of pipes based on non-destructive techniques of scanning acoustic microscopy (SAM). The results showed that the multiple necking deformation occurred...

Author(s) : Takashi Kuriyama, Kenji Mizukawa, Hiroyuki Kurio, Hiroaki Sakamoto

The Great Hanshin Earthquake that occurred on January 17, 1995, caused devastating damages to a large number of architectural structures such as high-rise apartment houses, and civil structures such as roads and bridges. This earthquake triggered the review of the quake-resistance standards of buildings and civil...

Author(s) : Akiyama, Higuchi, Nose, Toyoda, Kitano, Kuriyama

Since the year 2001, the Japan Gas Association has started the development of new renewal methods capable of cost reduction for modification work by inserting a new double-layered corrugated plastic pipe into the old gas pipe to encourage the modification of aged house pipes and upgrade the level of safety. The...

Author(s) : Akiyama, Kuriyama

The technical study group established by the Japan Gas Association examined the general design coefficient factor (C) to use polyethylene pipe to transport gas in Japan up to 0.3MPa. Because there are no results of the use of polyethylene pipe for gas in this high pressure range in Japan, we conducted a study...

Author(s) : Tsunaga, Matsunami, Sato, Nakata

By applying the cross-linked EF to the cross-linked PE(PEX) pipe \vhicli has a composite structure, the reliability of hot water piping system under severe environment lias significantly increased. A continuous use for approsimately 30 years under severe conditions such as 80 "C. and I MPa becomes possible. In this...

Author(s) : Kuriyama, Narisawa, Shiina, Kotaki

Unplasticized polyvinylchloride (PVC-U) is extensively used in the pressure pipe applications. These pipes are usually designed to have 50 year lifetime. Although their service performance is generally very satisfactory , there has been a number of cases where the pipes fail at unexpectedly short times. One of the...