Hardfacing PTAW:

In some cases, where it is necessary to treat a little part of a component with some mm welding only, it is normally used the PTAW (plasma transferred arc welding) technology, which fuses a metallic coating to a substrate in order improve its resistance against wear and/or corrosion. The whole process is carried out by using a specific powders mixture and the plasma-arc. While the HVOF technology is used for deposits on large surfaces and however with parts of medium seize, the PTAW technology is suggested for parts of small seize, treated in the critical sections only (usually the wearing ones). The deposits must be grounded

Note: in the valves production field, these hardfacings are fully used on lots of components. In case of minor components (such as bushes or similar), where HVOF and PTAW technologies cannot be applied or they turn out to be uneconomical, we can consider the possibility to supply components which are not hardfaced, but “complete”, for instance bushes made of stellite (cobalt alloys) fully grounded or made of other wearproof/anti-galling materials.