The Abrasion Resistance of Polymers in Slurry Environments

Author(s) : Ian Aldridge, Declan Robinson, Dave Smart, Chris Reed, Martyn, Greig, Trevor Stafford, David Christie-Lowe, Alec Erskine

For the UK polyethylene (PE) gas pipe network, the first installations now exceed 40 years in the ground, with an original design life of 50 years. It was thus timely to review the current condition and performance history of these first generation PE materials. A major 4 year project was started in 2010 to examine...

Author(s) : David Chrystie-Lowe

The many benefits of PE100 pipe materials include flexibility and toughness in addition to being relatively light products that are not subject to corrosion and expected to last well beyond the design lifetime [1]. It is also a distinct advantage that end-load resistant joints can be made using butt fusion (BF) and...

Author(s) : Sonya Pemberton, David Chrystie-Lowe, Sabah Rafiq, Karolina Modelska, Edward Ingham

A room temperature tensile test using thin films taken from the outside and inside surface of polymer pipes has been developed to study the slow crack growth resistance of ageing PE pipelines via analysis of their strain hardening behaviour. A range of PE materials in service since the early 1970s and 80s are studied,...

Author(s) : Dr. Dane Chang, Dr. David Marshall, Chris Cox

Plastic pipe applications often require polymers to have adequate abrasion resistance during usage. Although typical polyethylene resins have reasonably good resistance to abrasion and can be broadly used with a variety of chemicals, there are some demanding applications that require a resin with enhanced abrasion and...

Author(s) : Ken Murphy, David Lowe

Exova is continuing in the long tradition of Pipeline Developments Limited (PDL) in the UK with research, development, testing, quality assurance (QA) and failure analysis of modern plastic pipe materials and joints. Along with this ongoing work Exova has assessed various non destructive testing (NDT) techniques in an...

Author(s) : Lowe, Starkey, Powell

With the increasing success of PE100 and usage of pipes of increasingly large diameter, concerns have been raised about the quality of weld performance with relatively thick walled pipes (>50mm), which has led to the current investigation. In addition to the consideration of welding conditions adopted in the UK,...

Author(s) : MacKellar, Lowe, Ingham, Ashdown

Polyethylene (PE) is the preferred material for 90% of all water mains laid in the UK. The pace of renovation of dilapidated cast iron water networks has led to the increasing demand for coils of flexible PE pipe, driven by the efficiency of using less joints and taking up considerably less space in the congested...

Author(s) : Marshall, Brogden, Shepher

Many early brittle failures in PVC water and sewerage pipelines, where repeated surge events are thought likely to induce embrittlement, were attributed to fatigue. The concerns of pipeline engineers led to the adoption of the British Standard Code of Practice CP 312 (ref. 1) by the UK water industry, which gives...

Author(s) : Marshall, Morley, Pearson

The Water Industry in England and Wales has responsibility for an approximate length of 300,000km of water main, ~nuchof which was laid over 70 years ago using cast iron.Subsequently, asbestos cement, PVCu and cement lined ductile iron have been used. The old iron pipe systems that were installed in many of the...

Author(s) : Marshall, Hepburn, Netherwood

The adoption of polyethylene as a pipe material by both the gas and water indusmes has undoubtedly led to several sigruf~cant economic and operational advantages. The development of narrow trenching techniques and insertion refurbishment methods only became viable once a complete fusion jointed polyethylene system was...

Author(s) : Marshall, Ingham, Brogden

When clients purchase plastics pressure pipes, they have frequently made that decision because they know that plastics do not corrode and they assume that if they do not exceed the pressure rating then a long lifetime should be assured. (Low cost has also been known to be a factor). It is thus of concern for the...

Author(s) : Marshall, Birch, Morley

Many UK Water Companies are now using PE pipe systems because it 1s believed that use of an all-welded pipe will minimise the number of mechanical fittings employed and therefore will reduce potential sources of leakage. With pipes such as ductile iron and PVCu, which are joined in short lengths, it is often...

Author(s) : Lowe, Marshall

A Rotating Pipe Drum Test has been developed to assess the abrasion performance of plastics pipes to an extpnt where most test variables are understood. The procedure involves the rotation of relatively short pipe lcngths containing slurry on a conventional bail mlll. In the rest, the pipe surface repeatedly passes...

Author(s) : Marshall, Birch-Kisbenyi, Youd

A complete analysis of the Charpy impact system has been made to relate measurements of impact toughness to the geometry of samples. Using data obtained on pipe grade polyethylenes, Gc values at 20°C and 3°C have been found to correlate wel! with measurements of resistance to fast fracture in pressurised pipe...

Author(s) : Young, Thomas, Marshall

Within the Water Industry in England and Wales, there is an estimated length of 295,000 km of water main, much of which was laid in unlined cast iron prior to 1940. Subsequently, asbestos cement, UPVC and cement lined cast/ductile iron has been uscd. It is kn-that a substantial number of...

Author(s) : Marshall, Birch

It is proposed that present Specifications for PE Pressure pipes are essentially undemanding and tests do not simulate service conditions. Perfect pipes are assessed rather than pipes which have sustained handling and installation ‘damage’.Flaws and defects have caused many problems with other thermoplastics pipes and...

Author(s) : Marshall, Taylor, Dickinson

A study has been carried out which has sought to establish the influence of processing conditions on the properties of medium and high density polyethylene. Residual stress and fracture toughness measurements have been carried out on hdpe pipe, from which predications of the influence of diameterlwall thickness on the...

Author(s) : Birch, Marshall

The mechanics of failure of uPVC pipe materials have been investigated using fracture mechanics test methods to induce brittle failure. It has been found that brittle failure can be quantified and test procedures have been developed which are capable of being used as quality control methods for classifying pipe. High...

Author(s) : Birch, Howarth, Marshall

The paper is a brief resum of a large project which has sought to investigate the use of fracture mechanics in evaluating the failure properties of a number of common thermoplastics pressure pipe materials. In this outline, the results of tests made on uPVC and YDPE pipes are described. Pre-notched pipes have been...

Author(s) : Marshall, Williams

During the last ten years, it has often been predicted that plastics will be used in increasing quantities as true engineering materials, Whilst there has been an increased acceptance of GRP as a positive alternative to metals in many applications, the use of thermoplastics for major load bearing structures has been...