An Alternate Method for Determining the Hydrostatic Design Basis for Plastic

Author(s) : Jörg Wermelinger, Sunwoong Choi

In the development of an international standard on non-destructive test for polyethylene electrofusion socket (EF) joints, the inspection capability of the phased array ultrasonic test (PAUT) in assessing flaws in the joints was needed to establish procedure qualification of the test method. For this, a worldwide...

Author(s) : Sunwoong Choi, Tom Marti

Small scale, steady state (S4) testing per ISO 13477 is a lab-based procedure to determine the critical pressure at which a fracture will propagate following initiation in a given pipe material filled with a given test medium. The S4 test was originally developed for the natural gas industry using air as the test...

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...

Author(s) : Sooho Pyo, Junghyun Nam, Yoonsang Kim and Sunwoong Choi

The Notched Ring Test (NRT) has been recently developed to measure slow crack growth (SCG) in plastics pipes and fittings. The NRT specimen in the form of a notched full ring is directly obtained from the extruded pipe or injection molded fitting and has demonstrated its effectiveness in generating slow crack growth...

Author(s) : Pyo, Seo, Mutter, Broutman, Choi

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...

Author(s) : Newport, Wijeyesekara, Edwards

Research work undertaken at the University of East London has produced new forms of sustainable manufactured aggregate, which gives a backfill material which has many advantages over natural materials. The unique geotechnical properties of the aggregate make it an idea material for the laying of plastic pipes allowing...

Author(s) : Fairfield, Reid, Hounsome, Edwards, Sibbald

This paper provides estimates of the draw force needed to pull sub-ducts or cables through a series of typical ducted utility networks. Variables such as : coefficient of friction between the outside of the cable and inside of the duct, the main duct’s vertical diameter, the cable bundle or sub-duct’s external...

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...

Author(s) : Broutman, Edwards, Shah, Palermo

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...

Author(s) : Stokes, Edwards

The paper examines the business and regulatory background to the infrastructure investments anticipated in the next few years, from the point of view of a major UK Water Company. Past performance of the use of plastic pipes for sewers and water mains are examined. Shortcomings of the products are identified and...

Author(s) : Choi

A plane strain specimen has been developed which creates a biaxial stress state when loaded in uniaxial tension. A detailed stress analysis of this specimen is presented. The stress state was generated though the use of a groove across the width of the specimen. Both theoretical and experimental results are presented....

Author(s) : Duvall, Nylander, Broutman

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...

Author(s) : Edwards,Ellis, Georghiades,Smith

A model is presented for the prediction of cooling rates and temperature profiles during the cooling and solidification of M.D.P.E. pipes. Experimental measurements from an industrial production line are reported and these confirm the predictions of the model. Finally, the model is used to determine the most important...

Author(s) : Choi