Headford
# 1995 Edinburgh
A novel polyethylene stub flange adaptor is described which allows size-for-size connection, in terms of the respective bores, to iron pipes or fittings. The end load performance of this product is significantly superior to that achieved with conventional polyethylene flanges, especially at large pipe diameters, and the paper attempts to explain the reasons for this. Additionally there is evidence that the sealing performance of mechanical pipeline joints made using this component may be inherently superior, especially where pressure fluctuations occur. Referring to experimental evidence obtained with a slightly different embodiment of the device, it is argued that this potential for enhanced sealing could be fully realised in the case of the hoopreinforced flange by attention to design factors that would minimise stress relaxation effects within the clamped polyethylene shoulders.
Related papers
Author(s) : Shepherd, Headford, Jordan, Reeves, Walton
In Europe polyethylene (PE) has been chosen almost exclusively for gas mains for many years because of economic, technical and safety reasons but in the water industry a number of different materials are still used for pressure water mains. Indeed at sizes above 355mm (14 inch) most new large diameter water mains are...
Author(s) : Headford, Hill, Wilson
The United Kingdom is the most highly developed PE pressure pipe market in the world. Following pioneering work done in the USA and Germany, it was the UK that was first to adopt PE on a large scale for gas, and then for water distribution. The 100% PE policy of British Gas, and wide range of sizes used (at low...
Author(s) : MacKellar, Headford, Ingham
This paper provides an overview of the basic properties of plastic pipes, in the range 50mm to 400mm, and how these should be used in the design of above ground process pipe systems made of PE and PVC. It covers the basic properties of plastics, examples of the determination of load cases and describes the basic types...
Author(s) : Hill, Wilson, Headford
Butt fusion welding is the most reliable and unobtrusive method of joining PE pipes (and spigot fittings) of virtually any size-except perhaps the smallest where other methods are usually preferred. It is the dominant method of jointing both medium and large pipe sizes, but for different reasons. In medium pipe sizes...
Author(s) : Headford
Jointing Methods for Plastics Pipeline Systems AL Headford (Durapipe S & LP, UK) ee Introduction The basic requirements for pipe Jointing are common to all pipe systems made from any material (including traditional materials), whether they be for sealed pressure usage or non-pressure usage. These are a) minimal...
Author(s) : Boot, Headford
This paper summarises current design practices for buried thermoplastic pipelines subjected to combined gravity and internal pressure loadings. It suggests that accurate predictions of stabilised deformations are neither possible nor necessary, but that appropriate structural design methodologies should instead...
Author(s) : Beech, Headford, Hunt, Sandilands
The guldeUnes g h n in BS CP 312 :Pwt 2 : 1973 w e recommended to the UK toater industryfor the deslgn of polyethylene pfpeline systems to toke inin account the effects of tmnsient [surge) pressurejluctuatlons with respect to fatigue (ref.1). These guIdelInes we based on earlier experience wlth PVC-Usewer h i n g...
Members of the Association
