Stress intensity effect on slow crack growth in scratched polyethylene pipe [PE]

Author(s) : Cheng Zhi, Mingyuan Hu, Kaige Duan, Chaoxi Zhou, Dongming Yu

The PE properties are obviously improved by crosslinking modified to TPEX, which can approach to that of PEX, while still remaining thermoplastic. It can be processed by the common forming method of thermoplastic; the products can be hot-melted and the scrap can be processed to be reused. The two-layer structure...

Author(s) : Zhang Wei, Wei Ruoqi, Zhou Minghong, Zhou Mingwei,

This article gives a brief introduction of plastic inspection chambers in China. It focuses on the formulation of China's national standard for plastic inspection chambers and conducts the theoretical analysis and data validation of the key technical metrics in the standard for the following three tests: the...

Author(s) : Zhou Minhong

Rainwater can be used not only for washing road and irrigation, but also for flushing toilet, washing clothes and industry use. Moreover, storm water regulation and storage facilities help reducing the burden of drainage piping system, cutting down the investment of storm water pipelines and lowering the possibility...

Author(s) : Zhang Wei, Wei Ruoqi, Zhou Minghong, Zhou Mingwei,

This article gives a brief introduction of plastic inspection chambers underground test, analyzes the stress borne by plastic inspection chambers from different angles combined with pressure sensors and strain gauges, sorts out some of the underground test data and analyzes the test data, and finally sums up the...

Author(s) : Dr. Z. Jimmy Zhou, Jim Johnston

Heat fusion joining method has been widely used for thermoplastic piping materials such as polyethylene to form the “one-material” pipeline system. No additional 3rd party materials such as an adhesive are needed. The fusion procedures to ensure the quality of the joints could be different for different materials and...

Author(s) : Dr. Gene Palermo, Dr. Dane Chang, Dr. Jimmy Zhou

The scope of this paper is to provide information for the plastic piping industry on a test methodology that could determine the design life of heat fusion fittings and joints at the end user field conditions of operating stress, operating temperature and desired design life. This methodology is useful not only for...

Author(s) : Dr. Z. Jimmy Zhou, Dr. Dane Chang

External flaw could be introduced into pipe wall during the transportation, installation and service processes of polyethylene pipe. The performance of non-flawed pipe is well addressed by both the standard stress extrapolation methods specified in ASTM D 2837 and ISO 9080. However, there are very limited data for...

Author(s) : Zhang Wei, Wei Ruoqi, Zhou Minghong, Zhou Mingwei, Lin Baoshu, Xiao Lingli

The plastic inspection chamber is one of the rapidly developing products in the field of drainage in China for the past few years. At present, plastic inspection chamber is mainly made of PP, PE, PVC and so on. The manufacturing technologies include injection molding, rotational molding, mechanical assembly and...

Author(s) : Z. Jimmy Zhou

(Keywords : Polyethylene pipe, ligament stress, regression, notch depth, lifetime.) Hydrostatic test was conducted on notched PE100/PE4710 black pipe specimens at various temperatures and stresses. Hoop stresses were normalized to ligament stresses by taking into consideration of the effect of wall thickness reduction...

Author(s) : Zhou Minhong

As the key component of underground piping network for drainage, plastic inspection chambers have many major advantages and are also being applied more and more widely instead of traditional brick-built ones. Users become familiar with this new technique gradually. However there are two major problems which have...

Author(s) : Zhou Minhong

The advanced bimodal PE4710 materials enable its applications in large diameter gas pipe to replace cast iron and steel pipe. Among the three key field performances, the pressure rating is independent of pipe diameters. However, the SCG and RCP properties are dependent of pipe diameters. As pipe diameters increases,...

Author(s) : Chang, Zhou, Michie

MTD Pipeline LLC is a joint venture between Martin Marietta Magnesia Specialties LLC and The Dow Chemical Company. A nearly 30 miles of high density polyethylene (HDPE) pipeline project in northern Michigan is serving as the latest example of technology evolution for polyethylene (PE) pipe used in underground pipe...

Author(s) : Zhou, Chang

High density polyethylene (HDPE) pressure pipe may be scratched during installation. The scratches reduce the wall thickness and therefore increase the dimension ratio (SDR pipe). 1” SDR 11 pipe samples extruded from bimodal PE100/PE4710 and unimodal PE80/PE3408 pipe materials were used to investigate the effect of...

Author(s) : Zhou, Palermo

ISO MRS and ASTM HDB rating systems have been successfully used for more than four decades in Europe and North America. MRS differentiates well the three generations of HDPE materials by classifying them as PE63, PE80 and PE100. However, HDB classifies all three generations of HDPE as only one PE 3408. When...

Author(s) : Gustaaf SUYS, MA ZHOU, Dave CORDEROY

A sector of the Beijing Natural Gas Company network was to be converted from town gas to natural gas. It was found that the existing steel pipeline installed in 1983 could not withstand the working pressure, as parts of the steel pipes were seriously corroded. The system consisted of about 2.7 and 0.2 km of...

Author(s) : Vibien, Couch, Oliphant, Zhou, Zhang, Chudnovsky

The chlorine present in potable water as a disinfectant has been reported to reduce the lifetime of some plumbing system components. In this study the nature of the failure mechanism of a commercial cross-linked polyethylene (PEX) pipe material exposed in the laboratory to chlorinated potable water is examined. The...

Author(s) : Jivraj, Sehanobish, Dun, Damen, Wu, Zhou, Chen, Shulkin, Chudnovsky

Analysis of polyethylene (PE) pipes ductile failure (ballooning) suggests that it is directly related to the delayed necking phenomena and time to ductile failure of PE pipe can be evaluated as the time to delayed necking. The necking in polyethylene (PE) is studied under displacement control (ramp test) and load...