High Velocity Oxy-fuel (HVOF) Coating

The High Velocity Oxygen Fuel (HVOF) coating process is basically the same as the combustion powder spray process (LVOF) except that this process has been developed to produce extremely high spray velocity.

There are a number of HVOF guns which use different methods to achieve high velocity spraying. 

• One method is basically a high pressure water cooled combustion chamber and long nozzle. Fuel (kerosene, acetylene, propylene and hydrogen) and oxygen are fed into the chamber; combustion produces a hot high pressure flame which is forced down a nozzle increasing its velocity. Powder may be fed axially into the combustion chamber under high pressure or fed through the side of laval type nozzle where the pressure is lower.