A well-engineered PE piping system is not only dependent on good design. At Marley Pipe Systems, we strongly believe that strict adherence to quality standards is of critical importance throughout the value chain, from raw material selection through to the fabrication and installation of the pipelines that make up our country’s infrastructure.
In pursuit of the lowest possible cost, however, quality is often the first thing to be compromised by producers of plastic pipe products. This ‘quality compromise’ is apparent in the number of pipe failures that occur each year in South Africa.
Part of the problem is that there is little awareness of industry standards and specifications amongst buyers and specifiers of these products as well as the consequences of non-conformance to these quality control measures in relation to the overall life cycle cost of pipe systems.
As part of Marley’s “Quality Without Compromise” mandate, we’ve put together some of the trade-offs that are often made at the expense of quality in pipe production. By doing so, we hope to give the industry a better understanding of the contributing factors that put pipeline reliability at risk.
Compromise in the quality of raw materials
Manufacturers that compromise on quality over cost often source reworked material (regrind) from external suppliers. The use of regrind material of which the origin of the raw materials is unknown poses a risk of contamination and impurities, thereby lowering the overall quality of the pipe which could cost you in the long run.
Compromise in the quality of PE pipe fittings
Contractors often attribute failures to the poor quality of the fabricated fittings, when in reality it is a lack of understanding in the quality of what they were purchasing that is the problem. It is therefore essential for companies to be aware of and understand the design considerations and de-rating factors that affect the overall quality of fabricated fittings.
Compromise on quality specifications
SANS 4427 specifies the minimum requirements that PE piping system designers need to take into account in order to ensure the quality, safety and efficiency of the products that they produce. In an attempt to cut down on costs and materials, however, some manufacturers of pipes and fittings purposefully use less material or take shortcuts in the manufacturing process, resulting in irregularities in wall thickness along the pipe, also known as wall thickness fluctuation.
Compromise on quality process
Plastic pipes are generally subjected to many types of stress caused by different loads that could have potentially damaging effects to pipeline applications if not considered adequately. Consequently, manufacturers of pipe are required by stringent codes of practice to follow specific quality control processes which are put in place to ensure that the pipe design does not overstress any of the materials, thereby ensuring the safety of the piping system by verifying the structural integrity of the pipe against the expected loading conditions over the lifetime of the system.
Compromise on social and environmental responsibility
The plastic pipe manufacturing industry is characterised by modern manufacturing processes operating in a competitive and challenging environment. In addition to meeting a wide variety of exacting customer requirements, producers of pipe products must also respond to ongoing developments in the industry as a result of changing safety, health, environmental, quality and risk management issues.
For a detailed explanation of the topics covered above, click here download our full Quality Without Compromise booklet.