Our site uses cookies necessary for its proper functioning. To improve your experience, other cookies may be used: you can choose to disable them. This can be changed at any time via the Cookies link at the bottom of the page.


The protection provided by skinned polyethylene pipes in high ambient temperature and high ultraviolet (UV) regions [PE]

 

Plastic Pipes Conference Association # 2010 Vancouver

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 jointability of PE pressure pipes extruded with and without an integral and protective outer polypropylene (PP) skin, in the as-extruded form and after outdoor exposure in the Arizona desert to 3 GJ.m2 and 10 GJ.m2 of total radiation.
The stability of the resin trom the outer wall of the PE pipe was assessed after aging by measuring the oxidation induction time (OIT). The PP skin, even at 0.4mm thickness, provided protection for pipes receiving 10 GJ.m” of total radiation, as the OIT of the surface of the PE core pipe immediately below the skin was similar in value to the as-extruded and un-aged PE pipe. In contrast the OIT drops to close to zero for PE pipes without a protective skin when outdoor exposed to 3 GJ.m* of total radiation. Studies on the quality of electrofusion (EF) joints formed onto pipes after aging showed plain pipes (with no protective skin), prepared for EF joining by the use only of a cleaning cloth, had poor quality EF joints for 3 GJ.m* of total radiation, the de-cohesion tests being brittle in nature. In contrast, the skinned pipe subjected to 10 GJ.m” of total radiation prior to the peeling off of the PP skin, yielded high quality EF joints when the EF coupler was joined to the core PE pipe after removal of PP skin. The skin preserved the potential for high quality EF joints.
With ProFuse pipes the PP skin provides real protection from the effects of UV radiation and hign ambient temperatures, which then benefits the jointability of the core PE pipe, when joined by electrofusion. Utility companies in regions of high ambient temperatures and high UV radiation levels have much to gain from the use of skinned pipes of the correct structure, the skin protecting the core PE pipe to preserve or raise the integrity of water and gas distribution networks

Please note that the whole article content is available on PPCA website only :

Related papers

2006 Washington DC : An Effective Barrier Pipe System for Contaminated Land

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...

2006 Washington DC : Second Generation Skinned Pipes with Enhanced Fracture Resistance

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...

2004 Milan : A multilayer plastics and metals pipeline system for the conveyance of water through contaminated land; design and field experience

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...

2001 Munich : Optimising the Performance of Ferrule Straps with PVC Pipes

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...

1995 Edinburgh : Enhancing the performance of Plastics Pipes, Fittings & Joints

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...

1995 Edinburgh : High productivity butt fusion jointing of PE pipes

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...

1992 Eindhoven : Procedures of Quantifying the Strength of Electrofusion Joints

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...

1992 Eindhoven : The Influence of Time and Temperature on the Strength of a Multilayer Pressure Pipe

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...

1988 Bath : A new Manufacturing Technology for Large Diameter Polyethylene Pipe Fittings

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...

1988 Bath : Factors Controlling the Lifetimes of Polyethylene Pipes in the Slit Mode Failure Regime

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...

1988 Bath : The Fatigue Behaviour of Medium Density Polyethylene Pipe Systems

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...

1985 York : The Failure of Butt Fusion Joints in Polyethylene Pipe Systems

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...

1982 York : The Performance of Polyethylene Pipe Systems under Internal Fatigue Pressure Loadings

Author(s) : Barker, Bowman, Bevis

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...

Members of the Association

BOREALISBOROUGEFormosa Plastics CorporationHanwha TotalEnergiesINEOS O&PIRPCKorea Petrochemical IND. Co., LTD (KPIC)LyondellBasellPetroChina Dushanzi Petrochemical CompanyPRIME POLYMERSABICSCG Chemicals & Thai PolyethyleneSinopecTASNEE
TOP