Plastic Pipes in Plumbing Historical Development Modern day plumbing can trace its origins back to around 3000 BC. Whether you cite the early irrigation systems used in Babylon, or the Minoan palaces of Crete, early designs and installations of plumbing existed, including main sewers, ventilation ducts, even flushing toilets! In the last 5000 years, humankind has sought better and better

materials to use for this basic function. Early plumbing used materials such as stone, cement and manufactured earthenware pipes. Other materials have also been used, pitch fibre, iron, steel, lead, copper, even wood. But it is only in the last half century that the development of the plastic pipe revolutionized the industry. Post War Plastics First making its mark in the 1950’s when the technique of extruding PVC into

pipe first became available, this technical innovation resulted in the rapid replacement by PVC pipe of materials such as copper for pressurised water supplies and drainage. PVC’s resistance to corrosion and its higher strength made it infinitely superior. Its smooth walls however also made it resistant to the build up of bacteria, and recent spikes in the price of copper, with its consequent

susceptibility to theft, has made Plastic or Polymer Pipe the material of choice in most applications. For main water supply lines, PVC pipes are still the dominant choice, but High Density Polyethylene, Polypropylene, Glass Re-inforced Polyester, and the latest innovation Bi-axially oriented PVC pipe are also available.

For drainage applications PVC, HDPE and polypropylene are also the most popular selections, if for no other reason that the wide range of fittings that are available to form a designed solution. Some like it hot Where material choice has become a more contentious issue however, is when hot water is used, and for this there is literally a host of options from which to choose. Polybutylene (PB) was one of the early polymers, popular in the US, Britain and Australia.

Polypropylene (PP) and its later development into Polypropylene Random Copolymer (PPR) is also much used. Though not used in South Africa Chlorinated PVC (C-PVC) is also a material used overseas. But Polyethylene and its derivatives are fast becoming the new materials of choice for elevated temperatures. Polyethylene with resistance to Raised Temperatures (Pe-RT) and cross-linked Polyethylene (PEX) are quickly assuming a dominant role globally, and with these materials now being used in multi-layer systems where inner and outer layers enclose a middle ‘barrier’ layer, the

choice of systems becomes quite confusing. New Applications With new applications being investigated continuously, the use of polymer pipes for aggressive chemicals, oxygen supply lines, LP gas lines, compressed air systems and more is growing by the day. Underfloor heating, wall heating and cooling, even road heating and cooling - all these are applications currently utilizing polymer piping systems around the globe. Solar water heating is the latest growth market in construction. Whether the resultant hot water is used for pool heating or household hot water requirements. Polymer pipes can be used from the hot water storage cylinder (geyser) onwards, but NOT between the solar panel and the cylinder (See SANS 10254 part 2). Polymer pipes are far more efficient in these applications, having better insulation characteristics, and therefore

sacrificing less energy in terms of heat loss. Environmental Concerns This is a widely misunderstood topic, with plastic pipe often being slated as being environmentally unfriendly. The opposite is actually the case. Professor Käufer at the University in Berlin conducted an extensive study of the environmental impact of different pipe systems (VENOB study at TU Berlin, SHT article Sonderdruck 1995). Based on realistic installation examples, PE-X, PP-R, PB, PE-RT, copper and galvanized steel were evaluated by life cycle analyses. Evaluation criteria were emissions into the ground (VENOB method), waterborne and airborne emissions, and total energy consumption.

Environmental Impact of different Plumbing systems

The results of the study also show that the total energy consumption of Polymer piping systems is 30-50% lower than for metal pipes. All emission values calculated for the polyolefin systems were also considerably lower. Conclusion Though it seems to have taken 5 millennia, man has finally evolved from stone based, and subsequently metal based systems to the new range of polymer pipes. Efficiencies in manufacturing, heightened performance criteria and improved affordability have seen the growth of these plastic pipes across the world. Southern Africa is showing the same industry pattern, with widespread adoption of these materials and systems. Though there will always be specific applications, or resistance to change on the part of the contractor, those installations taking advantage of the new systems show improved productivity, increased life expectancy, lower maintenance and lower capital cost. It really is an unavoidably convincing argument! About the author: Ken Patrick is a marketing consultant operating in the construction industry. With extensive experience at one of South Africa’s largest plastic pipe

manufacturing companies, he is also the current chairman of PHACT (Polymer Hot And Cold Technology association), and serves on the relevant Technical Subcommittees of the SABS.