Evaluation of Aged Plastics Pipes Used in Natural Gas Distribution Systems [PE]
Duvall, Nylander, Broutman
# 1988 Bath
Thermoplastic gas distribution piping has been utilized in the United States for over 25 years. However, there is little data available on how such materials age in a service environment and how such aging might affect future performance. In this program, polyethylene pipe samples that were removed from actual gas service have been subjected to a number of physical and mechanical tests to assess aging effects. Aged pipe samples have also been tested for resistance to squeeze off; a commonly used emergency flow control procedure. This program was initiated by the Gas Research Institute (GRI) in 1984 to evaluate the condition of thermoplastic piping used for the distribution of natural gas in the United States. Over 200 individual samples of polyethylene pipe and a limited number of samples of PVC pipe were provided by gas utility companies.
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Author(s) : DALE B. EDWARDS, ANAND R. SHAH, DONALD E. DUVALL
Differential scanning calorimetry (DSC) has been used to study the processing of PVC pipes. This work has been largely embodied in ISO 18373-1-2007, Rigid PVC Pipes –differential scanning calorimetry (DSC) method – Part 1: Measurement of the processing temperature and Part 2: Measurement of the enthalpy of fusion for...
A novel Notched Ring Test (NRT) method for measuring slow crack growth (SCG) in plastics pipes and
fittings is developed and applied to determine its applicability as the standard test method. NRT specimen
in the form of a notched full ring, directly obtained from the extruded pipe or injection molded fitting...
The Alternate Methods Committee of the Plastics Pipe Institute’s Hydrostatic Stress Board (HSB) has completed development of an alternate method for determining the hydrostatic design basis (HDB) for plastic piping materials. The initial work was reported at Plastic Pipes X, in Sweden in 1998.1 An ASTM test method has...
Author(s) : Choi, Lee, Broutman, Edwards, Palermo, Cho, Choi, Park
In recently designated plane strain grooved tensile (PSGT) methodology of ASTM F2018
standard, a groove in the direction perpendicular to the loading axis allows biaxial stress
state to be generated under a uniaxial loading. The biaxial stress state produced very closely
approximates the internally pressurized pipes...
The Alternate Methods Committee of the Plastics Pipe Institute's Hydrostatic Stress Board (HSB) has initiated development of an alternate method for determining the hydrostatic design basis (HDB) for plastic piping materials. After reviewing several test methods, the plane-strain tensile method, developed by Choi and...