High Velocity Oxygen Fuel Spray (H.V.O.F.)

For High Velocity Oxygen (liquid) Fuel (HVOF) spraying, we use an oxygen-kerosene mixture. We axially feed the coating material, in powdered form, through the gun, generally using nitrogen as a carrier gas. The fuel is thoroughly mixed with oxygen within the gun and the mixture is then ejected from a nozzle and ignited outside the gun. The ignited gasses surround and uniformly heat the powdered spray material as it exits the gun and is propelled onto the workpiece surface.

Process basics

Schematic diagram of High Velocity Oxygen Fuel (HVOF) spray with liquid fuel.

Key characteristics

• Produces coatings that are very clean, hard, and dense with fine, homogeneous structures
• Coatings are tenaciously bonded to the substrate
• Has low compressive stress, which results in very thick coatings

Typical applications

• Gate valves
• Pelton turbines
• Ball valves