Pipes and valves

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Taking a look at piping systems that are leak free and durable for long term use

pipes and valves industry has been fairly quiet because of the economic slowdown in South Africa and some parts of the world, however the potential for growth is great since the Minister of Water Affairs and Forest promised that the government intends to spend billions of rands over the next ten years on infrastructural expansion and renovations in the areas of water and sewer related projects, says Bevan Richardson, Product Specialist, Marley Pipe Systems.

Pipes, whether plastic, concrete or steel, play an integral part of the infrastructure development, mainly to convey substances which can flow such as liquids and gases, slurries, powders, masses of small solids and, also for structural applications.

But before embarking on a decision on which pipe to buy, remember that each pipe whether plastic, steel or concrete has its unique properties, and it is therefore very important that the best material for a specific application be considered.

Some of the most important considerations if you are to get the most out of the pipe is its application, cost, strength, reliability, service life and joint integrity, installation and inspection, sustainability, material competition and engineer’s knowledge of materials.

Plastic Pipes
South Africa is waking up to the fact that water is fast becoming a critical problem. Quantity and quality are under severe pressure aggravated by fast increasing demand and huge loses in distribution. The focus is sharply on piping systems that are leak free and durable for long-term use and also on the rehabilitation of old mines. HDPE and PVC pipes answer these calls with distinction, commented SAPPMA Chairman, Jan Venter.

Polyvinylchloride (PVC) and Polyethylene, especially in the form of PVC-U, PVC-M, PVC-O and PE100 are some of the common plastic pipe materials used in South Africa. Pipes sizes currently range from 16 mm to 1000mm for pressure pipes and up 1 800 mm for non-pressure pipes.

The advantages of used plastics pipes stems from properties such as; Outstanding corrosion resistance; High flexibility and toughness; Energy efficiency; Increased resistance against many chemicals;  Low frictional resistance, with properties remaining in virtually unchanged over all of the pipe’s life; Light weight and ease of handling; Ease of jointing and Availability in a wide range of sizes and pressure ratings.

According to SAPPMA the plastic pipes industry is dynamic, and this is due to high-level of research and development by polymer manufacturers, the properties of pipe are continually being improved. Plastic pipe in South Africa is regulated by National Standards which are completely in line with international standards, and thus limiting deviations and short cuts in terms of pipe design, performance and mass of material used.

Steel Pipes
The advantages of steel piping systems set it apart from other competitor materials and it offers resistance to ultraviolet rays, thermal expansion and contraction, high pressures and stresses, mechanical damage and veld or forest fires.

Marley Pipe Systems: A True Value Partner
Marley Pipe Systems a member of the Aliaxis International, is a leading manufacturer and distributor of plastic pipes and fittings for reticulation systems, serving the key market segments of plumbing and building industries as well as the infrastructure sector through sub-Saharan Africa.
Marley supplies a comprehensive range of PVC, HDPE and PE pipes and fittings for a wide range of applications in the plumbing and building as well as civils, mining, irrigation and industrial sectors of Sub-Saharan Africa.

Marley Infrastructure has continued to grow with a number of success stories in South Africa and Africa. Recently the company successfully supplied over 98 km of 630mm PN6 HDPE pipes as well as about 2km of 630mm PN10 HDPE for the Angola Cunene Water Project, supplied pipes to Zambia and DRC especially in the Copperbelt region for irrigation, irrigation pipes to the Mozambican government, supplied pipes and fittings to the Leadwood Big Game Estate, Hoedspruit area, South Africa, successfully replaced the old existing water mains infrastructure with new HDPE pipelines in Woodstock, Cape Town and the rehabilitation process involved Trenchless technology, a technique that eliminates the need for conventional open trenches.

After the acquisition of Bates Torkers, Marley now supplies the Weholite HDPE pipes, utilizing a unique, profiled-wall pipe structure that makes it possible to manufacture pipes in diameters up to 1.8m for stormwater and culverts. It provides all the advantages of solid wall polyethylene pipe with substantial savings in weight for increased ease installation and cost effectiveness, Says Richardson.

DPI Plastics
DPI Plastics- a leading manufacturer of water reticulation, drainage and pipefitting systems in South Africa has begun the production of its new 630 mm bore PVC pipes following the installation of a new Krauss Maffei extrusion line.

According to DPI Plastics technical and product manager Renier Snyman, the new extrusion line will open up new avenues of growth for PVC as a competitor in the bulk water, stormwater and sewerage industries, which are currently dominated by materials such as steel and concrete. “PVC is more cost effective and boasts a longer life expectancy, when compared to industry standard steel and concrete”.

Synman explains that steel and concrete are often prone to significant corrosion damage over extended periods. “In addition to having superior corrosion resistance properties, PVC is highly durable, with low frictional resistance and low wave celerity, thereby ensuring resistance to surges”, he adds.

DPI Plastics will be manufacturing a total of three 630 mm PVC piping products using the new krauss Maffei extrusion line, namely: a SANS 966 approved uPVC with pressure ratings up to 9 Bar, a SANS 966 approved mPVC pipe with pressure ratings up to 12 Bar and a SANS 791 approved underground sewerage and drainage pipe, which is available in both standard duty and heavy duty options.

In addition to be readily available in South Africa, Synman indicates that the entire new 630 mm PVC piping will be exported into Africa too. Our clients in Africa have shown considerable amount of interest in the 630 mm PVC piping range. With continued infrastructural development taking place across the continent, I am confident that the new range can obtain measurable market share within a relatively short period of time”.

At the end of the day different types of pipes are suitable for different conditions and remember poor installation, adverse conditions such as flooding, drought, changing soil conditions, heavy traffic, and veld fires have negative effects on the life of a pipe. Using the right pipe for the correct purpose, trench design, and choice of backfill, quality of compaction and methods of joining are paramount to the performance of pipes.