Butt Fusion in Logistically Challenging Jobsites

Author(s) : Amanda Hawkins, Jason Lawrence, Xiangli Meng 2018 Las-Vegas

High Density Polyethylene pipes are used in various applications due to the material’s superior chemical resistance, pressure capability, and ductility. For the material to perform at the optimal design criteria, the connections and fabrications must be fused using repeatable procedures that specify proper fusion...

Author(s) : Robert Lawrence, Mohana Murali 2018 Las-Vegas

The paper covers the growth of the polyethylene pipe sector in the Middle East from the 90s to the present. The initial slow uptake was related to ignorance of the material properties from the end users through to designers and installers. Recently the Middle East has become a world leader in the use of ever larger...

Author(s) : Edward Alan Ambler, John Matthews, Lawrence Pultz, Ryan Stowe 2016 Berlin

This paper summarizes the design and implementation of the largest asbestos cement pipe bursting project performed to date within the United States. The paper also presents regulatory information required to properly track and document an asbestos cement pipe bursting project while meeting the National Emissions...

Author(s) : Robert J Lawrence 2014 Chicago

In the Middle East the environment is exceptionally aggressive for all pipe systems due to the high temperatures, the high groundwater table and the very saline soils. This obviously makes metallic pipes and cement based pipes high risk options but it also poses challenges for polyolefin (PO). In this paper the author...

Author(s) : A.C. Seibi, R. J. Lawrence, R. Jepson and Z. Tarik 2012 Barcelona

Design and fabrication of plastic pipe fittings have been governed by ISO 4427 where pressure derating factors of 0.8 and 0.5 have been used respectively for fabricated elbows and tees. However, laboratory data generally indicate that these derating factors are very conservative. Moreover, the design of distribution...

Author(s) : Lawrence, Rasbash, Potter, Teo 1998 Gothenburg

Structured wall plastic pipe has been in existence for many years, but there remains a need for an appropriate method for assessing the durability of their comparatively thin walls in actual service. In normal operation this has not manifest itself as a problem, but the fact that damage can be sustained during...

Author(s) : Lawrence, Potter, Teo 1998 Gothenburg

The short term testing of any plastic pipe for its prospective longevity in service is extremely difficult because it requires some accelerated technique which needs to work within or verv close to the normal operatin? strains if extensive creep processes are to be avoided. The problem has now been exacerbated by the...

Author(s) : Lawrence, Teo, Potter 1998 Gothenburg

There is increasing evidence that dynamic testing is a most powerful. if not the only practical, method of evaluating whole plastic pipe for its long term service potential. Indeed in some instances this method is used as the primary indicator of performance in the researcNdevelopmentaI process of these...

Author(s) : Lawrence, Potter, Teo 1998 Gothenburg

When butt welds fail in servicc it is normal to find that the initiation site of the fracture occurs at the point where the roll bead attaches to the main body of the pipe. The ratio of hoop stress to longitudinal stress for 'thin walled' pipe is approximately 2 : 1 and so it is more likely that these transverse...

Author(s) : Ansell, Lawrence 1998 Gothenburg

Recent years have seen the steadily increasing use of thermoplastics for pipes and fittings for domestic hot and cold water supply and heating installations. Plastic pipe systems, in particular those that incorporate a push-in design offer considerable advantages over conventional pipe systems. However, manufacturers...