Coating of water pipes and fittings
The main objective of this project is to showcase a new technology to the water industry, for the coating of water pipes and fittings.
The coating will greatly improve corrosion protection and subsequent longevity of coated pipe network, in an economical manner.
With the proposed technology, the water authority will stand to maximise the expected lifespan of the water distribution network by ensuring that water pipes and fittings are given the best possible corrosion protection, with excellent adhesion to the metal without the need for a primer.
The water authority can also be safe in the knowledge that the coating does not leach any harmful chemicals in the water or the surrounding environment.
PPA 571 Aqua is a thermoplastic material. Contrary to Fusion Bonded Epoxy or any other thermoset material, PPA 571 thermoplastic coatings do not polymerize, they only fuse and bond to the metal when heated up. Thermoplastic materials are intrinsically very flexible and elastic, which confers very good impact and abrasion resistance to the coating.
Because the material does not need to polymerize, there is no risk of incomplete curing, which can often happen with FBE, leading to an impairment of the physical properties and resulting performances. PPA 571 Aqua can also be repaired using the same material: Plascoat supplies strands of PPA 571 material to allow repair of the coating in case any imperfection or defect arise during the coating process. PPA 571 Aqua also presents other advantages compared to Epoxy: they are fully UV resistant and Bisphenol A free.
In South Africa, Polyamide (Nylon) powder coating are quite popular, it has been widely specified by the Water Companies and just like PPA 571 Aqua, is based on thermoplastic technology.
However, PPA 571 Aqua differs from Nylon in the fact that it does not require the application of a primer to activate adhesion between the coating and the metal. This allows manufacturers to eliminate one production step, therefore saving on processing cost.
From a commercial point of view, PPA 571 Aqua is much more economical to use compared to Nylon. Nylon, FBE, sleeve, galvanised steel and bitumen are all used to coat the outside of Water Pipes and Fittings and PPA 571 Aqua presents numerous advantages against all these systems.
Simon Scruton Pr. Eng. MSc. Eng (Civil) MSAICE
Senior Manager: Non-Revenue Water Branch eThekwini Water and Sanitation
Tel: +27 (0) 31 311 8744
Preliminary results of the showcase will be based on application trials results: can the coating be applied easily by the coater, and does it give the expected level of performance: adhesion, integrity, thickness control + any other long term performance testing that the water authority may want to have performed.