South Africa loses an estimated 1 580 million cubic metres of water each year to water leaks with more than 36% of the total municipal water supplied lost before it reaches customers, according to the Water Research Commission.
While plastic is often associated with negative connotations, the reality is that the plastics industry has done much to improve the quality of human existence and is playing an increasingly important role in ensuring food safety, light weighting of motor vehicles which leads to reduced fuel consumption, and packaging for the healthcare industry. Plastic is also used in pressure pipe applications for the transport of drinking water and waste to and from our homes as well as heating gas distribution systems.

High-density polyethylene (HDPE) – a thermoplastic polymer – has become an attractive material to produce piping given its durability, flexibility and ability to be moulded to any shape as well as its ability to resist corrosion. Introduced more than 60 years ago, HDPE pressure pipes are playing an important role in keeping utilities around the world intact and reducing maintenance and replacement costs. Amongst its many benefits are a lower leakage rate, particularly when compared to legacy materials.

High Density Polyethylene is resistant to soil movement and tends to lie intact after a major seismic event such as earthquake. Designed to last longer than 50 years, recent studies reveal that when correctly manufactured and installed, HDPE pressure pipes may last as long as 100 years.

Life cycle assessment studies conducted by The European Plastic Pipes and Fittings Association (TEPPFA) have established that the environmental impact of plastic pipes is much lower compared to non-plastic alternatives such as cast iron, ductile iron and concrete.

Safripol is the second largest polymer producer in Sub-Saharan Africa. Speaking at the company’s Pressure Pipes Conference in Johannesburg recently, CEO Nico van Niekerk explained that the company plans to exit single use plastic. Its campaign to use plastic responsibly has three pillars: enhancing the circular economy; reducing its environmental impact; and ensuring a positive social impact.

Nyambeni Luruli, Technical Services and Development Leader at Safripol, said the company’s strategy is to develop materials that are sufficiently durable for long-term applications, can be re-used and are easily recyclable. “HDPE pipes tick the box on all these requirements,” he said.

HDPE pipes can be used as conduits for water, wastewater, gas, hydrogen as well as electrical and communication systems. Manufacturers are required to undergo a stringent compliance process before the pipes are certified with the standards required for compliance differing depending on the intended end-use of the pipes. Certification marks need to be clearly visible on all HDPE pipes and pipes laid so that the markings are clearly visible. Although ensuring compliance during the manufacturing and installation process is time-consuming, it potentially alleviates costly remedial works.

Key to HDPE pipes achieving the longer than expected lifetime is that they are manufactured to the correct Standards and also correctly installed, pointed out George Diliyannis, Senior Application Engineer at Safripol. He said HDPE pressure piping offers huge advantages to South Africa, particularly given a looming water crisis. “In addition to helping to alleviate water loss due to leakages, it allows for quicker installation when compared to legacy materials and could help to reduce the country’s significant infrastructure maintenance bill.”

In Southern Africa, large diameter HDPE pressure pipes have been successfully installed at Hammanskraal and Maputo, the latter to supply drinking water to Maputo via a bridge crossing.

“The manufacture of pressure pipes has evolved significantly in recent decades. As an industry we now need to keep building on the quality foundations that have been established to ensure that what we build today remains in place for generations to come,” concluded Gert Claasen, Technology and Innovation Executive at Safripol.