TPi October 2010

pipes PVC, PE & XLPE

heated wires embedded in a moulded coupling.

into the GPS peelable pipe, Secura- Line. This was quickly followed by a multi-layer barrier pipe for petrol and the first barrier pipes for potable water in contaminated land, Protecta-Line. From very early beginnings pipe systems have diversified in terms of their materials and design, undergoing rapid development in recent decades. In the water and gas industries, this has culminated in HDPE pipe systems that offer an extremely long service life, high performance and installation benefits. There are currently no better alternatives to take their place. On this basis innovative manufacturers, such as GPS PE Pipe Systems, continually seek to offer new solutions in water and gas distribution using this versatile material.

In the following year the PushFast spigot and socket system was introduced, and by the end of the 1980s the group had brought in the ‘Rolldown’ trenchless pipe installation technique, high strength PE100 pipe and had manufactured the UK’s largest diameter PE pipe. This was a 630mm pipe installed by Thames Water at Blake’s Lock, Reading. Over the next decade GPS was responsible for taking the application of PE pipe systems in a number of new directions. In 1994 the group produced the first skinned PE pipe, for the Severn Trent Water Authority. Providing protection for the pipe surface during installation and enabling a clean surface to be presented for electrofusion jointing, this innovation was developed

Stewarts and Lloyds was formed in 1895, by the merger of A&J Stewart and Menzies Ltd and Lloyd and Lloyd Ltd

began life in 1919 when Lt Ernest Tribe of the Royal Engineers founded the Victory Pipe Joint Company. His Victaulic joint was invented in 1922 and was the basis of what is still today an extremely robust and reliable jointing method for pressure pipe. This was also the branch of the group that in 1930 gave birth to the Viking Johnson high tolerance pipe coupling, suitable for joining dissimilar pipes. This was also a critical period in the development of plastic pipe systems. Polyvinyl chloride pipe was in production between the wars, although it was largely reliant on fabrication of relatively short pipe lengths. The way forward lay in producing plastic pipes by continuous extrusion, and by the time extrusion technology was maturing in the 1950s, high density polyethylene (HDPE) had appeared on the scene. The arrival of HDPE offered a superior material to PVC for piping pressurised water. The inherent strength of HDPE was significant in its suitability for water and gas pipes but above all its ductility – resistance to brittle failure – was key. Coincidentally, ductile iron was also introduced in the UK as a pipe material in the 1950s and has remained a competitor to PE since then. As PE pipe systems began to be accepted and installed by the water and gas utilities, the Glynwed companies (the antecedents of today’s UK manufacturer GPS PE Pipe Systems) were prominent in developing new products and manufacturing methods. These included, in 1979, the UK’s first electrofusion joint, with electrically

GPS PE Pipe Systems – UK www.gpsuk.com

A stack of modern plastic pipes

SF PVC (thermo plastic PVC) duct from Novaflex features a special molecularly bonded construction, for reduced turbulence and increased flow efficiency. The duct is suitable for many industrial applications, including the transport of particles and gaseous media. The duct is constructed from premium clear polyvinyl chloride, allowing for continuous visual monitoring, and is manufactured with FDA approved materials. It is suitable for light duty Clear PVC duct

material handling, and has good resistance to oil, alkali and acids, as well as being very flexible, with good abrasion resistance. The duct is available in sizes from 1.5" to 24", in 25 and 50ft lengths (up to 8" diameter) or 20ft lengths (10" diameter and greater). The temperature range is 20°F to 165°F.

Novaflex Group – Canada sales@novaflex.com www.novaflex.com

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October 2010 Tube Products International