pta hardfacing

The recently installed Robotic PTA welding systems puts MES in a unique position, making it the first company in South Africa to have a completely integrated, robotically controlled PTA welding system. PTA (Plasma Transferred Arc) is an advanced technological method of depositing super-alloys metallurgically to the substrate material. The technology allows the company to apply Cobalt, Nickel and Tungsten hardfacing materials to wood chipping components such bedblocks and knife clamps. Other applications are in the repair ship valve and  is also suitable for hardfacing high-wearing components like wear rings, valve seats, paddles and extruder screws to name a few. Using a robotic control together with PTA welder produces tougher more wear resistant deposits resulting in smooth, consistent downlays reducing post machining and grinding time and associated costs. Robotic automation together with the PTA welding PLC system allows for easy storage of job parameters.


Pump rings  are coated with Stellite 6 using the PTA Process. The advantages of the coatings are for anti-galling and abrasion resistance. The coatings also stand up well to chemical corrosion due to the dense smooth surface with very little cracking. Rings of this type can be coated in a variety of materials from Nickel and cobalt based powders to Tungsten coatings. Due to the even lay down of the coating by the robotic welder machining and grinding times are greatly reduced making it cost effective.


The company has an in-house thermal spray facility performing extensive work in the coating of gland packing sleeves for pumps. Sleeves are coated with nickel-based and tungsten alloys as well as ceramic. MES thermal coating achieves high levels of wear resistance and its processes have made it the preferred supplier to Mondi Merebank, SAPREF Refinery and Sappi Saiccor for many years. MES has been an approved Stellite applicator for the last five years. All coating powders applied can be traced back to batch numbers and supplier certification guaranteeing that only genuine materials stipulated by the customer are used.