Understanding weld standards crucial to the welding industry

o ensure quality in the welding industry, pipes supplier Marley Pipe Systems product specialist Ian Venter says it is important to not only use the standards required in welding but also understand them. Delivering a keynote address at the Thermoplastic Welding Technology Day, hosted by industry body Plastics SA last month, Venter said common variables – including the working environment and environmental conditions, the condition of the product, product preparation, and health and safety – needed to be taken into consideration on a weld.

He explained that the working and external environments could drastically change the dynamic of a weld, as a weld done earlier in the morning amid cooler temperatures, and possibly moisture, would not be the same as a weld done at midday in warmer dryer conditions. “Other contributing factors which affect the dynamic of the weld include airflow in the pipe; foreign matter, such as water or sand; scars or scratches on the product; and other contaminants, such as oily fingerprints.”

The quality of products being supplied must also be high. Over time, polymers often suffer oxidisation and material degradation when left out in the elements. Venter said the duration of a project, especially if spanning over different seasons, and the time it would take to supply products, must also be taken into account.

“Product preparation is also becoming a factor when welds are assessed. Incorrect preparation, through lack of proper training or reluctance to go through the procedures required, can lead to a faulty weld.”

Moreover, Venter highlighted that each weld must be recorded to ensure quality and traceability. This includes the date, time, type of machine used, atmospheric conditions and the type of tests done on the weld.

“This is not necessarily used to find and fix failures, but more as a preventive process that will identify problems before they arise. A record should be made daily, which should be available to site managers and inspectors at any time so that if they note any deviations in weld information, they can address issues immediately.”

Independent consultant to the plastics industry Jacques van Eck added that to ensure a quality installation, a customer has to look at the ISO 9001 certificate, a certificate of analysis from the raw materials supplier and a certificate of conformance issued by the pipes manufacturer before a project starts.

Van Eck said companies that had Southern African Plastic Pipe Manufacturers Association, and Installation and Fabrication Pipes Association certifications strive to offer a higher standard product than non-affiliated pipes manufacturers, and are regularly audited to maintain their affiliate memberships.

“If you go through all the necessary welding processes and acquire all the product certification and documentation for your project, you will have not only peace of mind but also security in knowing your piping system complies with all the necessary standards,” he concluded.