Second Generation Skinned Pipes with Enhanced Fracture Resistance [PE]

Author(s) : Derek Muckle

It has long been the case that plastic pipes have been subject of folding operations in a factory and then supplied to site for use in pipeline renovation applications. The same cannot be said for pipes subject to diameter reduction as they have, as a principle, relied on being diameter reduced at site in a forming...

Author(s) : Derek Muckle

Polyethylene pipe is being routinely used for the close fit lining of large diameter water trunk mains, with the twin objectives of improving water quality and reducing losses due to leakage. Trunk mains serve large urban areas and by definition are large diameter pipes; examples of real lining schemes in the past 12...

Author(s) : J.Bowman

Polyethylene (PE) resins are known to be sensitive to both sunlight and high ambient temperatures, such that excessive exposure can degrade the material. The inclusion of stabiliser packages into the polymer controls this potential for damage from outdoor aging. Reported in this paper are results on the stability and...

Author(s) : Derek Muckle

Polyethylene pipes are widely used across the utilities sector for the safe, reliable, transportation of gas or water under pressure. The success of the material in being adopted is partly due to the ability to treat it as an engineering polymer whose properties and failure modes are well understood, predictable, and...

Author(s) : Christodoulou, Wilson, Hunter, Bowman

Polyethylene (PE) based and metallic pipe systems have been assessed for their ability to stop petrol migrating through the pipe wall, fitting or joint and into water contained within the pipe. A quantitative test was devised that is capable of distinguishing between the different pipe systems. Plain PE pipe...

Author(s) : Hunter, Christodoulou, Greaves, Bowman, Bott

The development of a pipe system designed to transport potable water through contaminated ‘brown-field land’ is described. The system is based around a multi-layer, aluminium reinforced PE pipe, and includes a full range of specially designed mechanical fittings to provide the end user with a total system solution. We...

Author(s) : Muckle

In 1999 the Health & Safety Executive agreed to the introduction of a new risk based methodology to be used for prioritising iron mains replacement. The introduction of this methodology combined with the results of major incident investigations has led the Health & Safety Executive to conclude that the potential risk...

Author(s) : Stokes, Potter, Metcalfe, Bowman, Graham

The response of three different forms of polyvinyl chloride (PVC) pipe has been explored when the pipes had attached to them ferrule straps. Pipes were subjected to fluctuating internal pressure (fatigue) loading at 20°C, and the lifetimes, location of any failures and the types of failures recorded. Tests were made...

Author(s) : Morgan, Muckle, Scott

A three way partnership has resulted in the development of a new solution to the refurbishment of old iron and steel gas service pipes. The solution which has been developed allows a flexible polyethylene replacement pipe to be inserted into the old pipe system. This avoids the need for the costly excavations or...

Author(s) : Muckle, Wood, Reed

Developed to address the practical problems experienced on site with the preparation of the surface of polyethylene (PE) pipes for electrofusion jointing, skinned PE pipe also offers the secondary benefit of general pipe protection against gouging and other forms of abrasion damage. This paper discilsses the concept...

Author(s) : Bowman

The many technologies associated with the production, installation and uses of plastics pipes systems increase in their sophistication and diversity This paper selects and reviews changes that have and are taking place with polyvinyl chloride (PVC) and polyethylene (PE) pressure pipe systems designed for canying...

Author(s) : Burn, Richards

Fracture toughness tests have been used with uPVC pipe for more than a decade. Standard methods of testing are described in British and ASTM Standards and in an I S 0 draft. Analysis of the British methods associated with the introduction of a fracture toughness test into joint Ausmlia/New Zealand Standards for...

Author(s) : Cartwright, Troughton, Hinchcliff, Bowman, Jenkins

For the butt fusion joining of PE80 polyethylene pipes on site, long heat soak and cooling times predominate in the United Kingdom and other countries. The literature is reviewed to propose that these heat soak and cooling times can be significantly reduced via the use of machines with verifiable, reduced short...

Author(s) : Dib, Day, Benkreira, Wood

A computer program for the prediction and optimisation of process parameters for the butt fusion welding of polymer pipes is described. At the core of the program a mathematical model predicts bead size, melt layer thickness,pipe displacement and temperature : time history during each stage of the process for...

Author(s) : Wood, Moore

The erosion of pipe materials in slurry flow streams occurs through a variety of wear processes. As a result, the comparative wear resistance of materials is extremely difficult to predict from a knowledge of basic physical and engineering properties. Design and selection criteria must hence be based on empirical...

Author(s) : Bowman,Medhurst, Portas

For two sample shapes different procedures have been examined as methods to quickly and quantitatively assess the strength of electrofusion joints. It is shown that the peel test, specified in BS7336, can be added to in order to obtain a quantitative measure of joint strength either using the % ductility on the...

Author(s) : Bowman

The influence of time and temperature on the long term strength of a multilayer pressure pipe has been investigated. The pipe consists of five layers, one of which is an aluminium foil while the other four layers are polyethylene based and form the significant ( > 8 5 % ) part of the pipe wall. In respect of strength...

Author(s) : Aboutorabi, Bowman

A rwte for the marufaoture of large diameter polyethylene pipe fittings, based on a unique combination of mtommld- ing and irradiation, is pmposed. The method requires a low investment in twling but can give rise to pressure rated, mulded fittings, capable of being fusion jointed to polyethylene pipe. This...

Author(s) : Wright, Bowman

Studies are reported on the performance of pipes produced fmm selected blends of polyethylene materials. The pipes were tested at a single temperature of 80°C and at irternal pressures designed to induce slit-mode failure. It is shown that blending the wrong polyethylene resins can substantially reduce performance of...

Author(s) : Bowman

Elevated teqerature fatigue of MDPE pipe system showed socket and electrofusion fittings had similar fatigue lifetimes, while butt jointed pipes failed at repmducibly lower lifetimes. Extrapolatims to 2O'C preserved the raking in joint performance, although combined creep ad fatigre tests showed pure fatigue...