HVOF coating is based on the principle of burning a mixture of fuel gas (such as propane, hydrogen, or kerosene) and oxygen under high pressure, then expelling the combustion gases through a nozzle at supersonic speed. The coating powder is injected into this high-velocity gas stream and impacts the surface at speeds of 800–1000 m/s. As a result, a mechanically dense, high-surface-density coating with strong adhesion is applied to the component.