# 1982 York
The influence of the incorporation of injection moulded fittings and the presence of mirror plate butt welded joints on the performance of polyethylene pipe systems has been assessed. Systems have been tested at 79.5OC under, predominantly, internal fatigue pressure loading. Both fittings and butt welded joints have been shown to be sites for premature failure under fatigue loading. The fall off in system performance for some systems can be substantial.
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) : 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) : Wood, Richards, Street, Muckle, Bowman
For the movement of fuel gas and water, plastics pipes are dominant in many markets, and this success has been based on single material solid wall pipes. There are now an expanding number of multi-layered plastics pipes, and described here for the first time is the performance of the second-generation of skinned 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...
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) : Allan, Hashemi, Faulkner, Bevis
A novel moulding process has been developed at the Wolfson Centre for Materials Processing, Bmnel University, for the production of curvilinear forms of thermoplastic materials. The process has been used with a gas pipe grade of medium density polyethylene to manufacture right-angled elbows of 63mm diameter SDR 11...
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) : 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) : 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) : Bevis
Europe has accepted that resources should be recycled to avoid waste and is incorporated in European Community stragegy for waste management : - The prevention and reduction of waste arisings at source.- The increased use of recycling and re-use of materials wherever possible.- The safe disposal of unavoidable...
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...
Author(s) : Parmar, Bowman
The performance of aligned and controlled misaligned butt welds in 63 and 90mm polyethylene pipe systems was determined under fatigue loading conditions designed to induce brittle failure. The results showed a significant reduction in fatigue lifetime for butt welds having fractional misalignments greater than 10% of...
Author(s) : Barker
Glass reinforced thermosetting plastic pipes share with thermoplastic pipes the advantages of corrosion resistance and lightness. They are currently finding increasing market acceptance, especially for large diameter water distribution and sewerage applications where the alternatives of concrete, steel...
Author(s) : Allan, Bevis, Chuah, Ma
