# 1988 Bath
Two of the pipe resins that are commonly used in the USA are compared with respect to their relative life times. The improvement in the performances of the currently used materials compared to the older material from the same producer have been measured. T h e 1ahoratoi-Y conditions for producing brittle failure in our notched specimens in the minimum time are presented.
Author(s) : Xiaoying Lu, Yujie Wang, Qiang Huang, Chunyan Xu, Guangyu Zhu, Aimin Xiang, Linmei Wu, Yanfang Wang
The determination method of metal elements for polyethylene pipes was reported in this paper, the difference in metal elements content between raw materials and recycled materials was analyzed. The results showed that raw and recycled materials in polyethylene pipes were effectively distinguished via metal element...
Author(s) : Troughton, Brown, Hessel, Piovano
As part of the Polytec Systems European-funded project, electrofusion (EF) joints in polyethylene (PE) pipe, containing different flaws, have been subjected to various standard and non-standard, long-term and short-term, coupon and whole pipe tests. The results were compared to determine which tests could discriminate...
Author(s) : N. Brown
The three major requirements for a gas pipe resin are (1) the MRS , (2) excellent resistance to slow crack growth[SCG] and (3) resistance to brittle fast fracture as exhibited by a low S4 critical temperature,[Tc]. In order to develop a new PE resin, it is necessary to investigate many variables involving the...
Author(s) : Lu, Burn, Whittle
For rubber ring joints to resist plant root penetration, it has been reported and promulgated into Australian Standards that a sufficiently high contact pressure between the rubber and the pipe must be maintained. The evaluation of the appropriate interfacial pressure to be used has been under discussion for some time...
Author(s) : Brown, Lu
The S4 critical temperature (CT) for 110 mm pipe was correlated with the plane stress impact energy for 13 resins. A plane stress impact (PSI) test is offered as an inexpensive way to control RCP by determining the lot to lot variations of the critical temperature of a resin. Details of the PSI test are presented.
Author(s) : Lu, Burn
One of the characteristic behaviours of plastics (or viscoelastics) materials is the creep phenomenon, which is defined as the continuing deformation under a constant load with time. Although research on creep of plastics pipes has been widely carried out in other plastics, little work has been reported for creep in...
Author(s) : Dear, Brown, Mason
The threshold load to just maintain crack propagation and conditions for catastrophic failure, should the material be loaded above this threshold, are two key evaluation requirements when assessing polymers for pipe applications. Often these assessments need to be made during material research and development and...
Author(s) : Lowdon, Chantre, Brown
The Water Distribution Technical Centre Lyonnaise des Eaux operates a network of three water distribution technical centres which serve the needs of the Lyonnaise des Eaux Group in the area of potable water distribution technology. The main centre, known as the Water Distribution Technical Centre (WDTC), is based at...
Author(s) : Brown
ASTM D2837 and ISO/TR 9080 for validating PE resins were analyzed. It was found that the difference between 11.3 yr. and 50 yr. as specified in D2837 and ISO/TR 9080, respectively, has very little effect on the determination of the Long Time Hydrostatic Strength (LTHS) at the service temperature, but this difference...
Author(s) : Brown, Lu
The test, called PENT, consists in measuring the resistance to slow crack growth of precisely notched specimens under constant load in air. The specimen geometry is designed and conditions are chosen so that failure is by slow crack growth as occurs under service in the field. The test conditions for producing failure...
Author(s) : Brown
Slow crack growth in polyethylene involves one of the most complex fracture processes in the field of fracture mechanics and especially; very little is known about the initiation mechanism. It is generally believed that there is a critical value of the stress intensity, K, below which crack growth does not occur in...
Author(s) : Brown
An early record of the use of a l'plastictl or flexible pipe is in 1733 when the Re\/. Stephen Hales wished to measure the blood pressure of a horse. He had a brass canula, to insert into an artery, and a long glass tube; but he had to find a flexible pipe to connect the two. His solution was to use the trachea, or...
