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.
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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...
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...
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...
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...
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
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...
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...