The tungsten carbide coating, chromium carbide, stellite is widely used for metallic seats and balls with metallic seal.
This coating is carried out using the HVOF (Hight Velocity Oxygen Fuel) process, which, using high speed, projects carbide particles in the seals and achieves high adhesion strength, 1400 HV hardness, and low porosity.
The thicknesses that can be carried are mainly 150 μ, 200 μ, 400 μ, depending on the characteristics of the valves’ use.
After finishing coating, the seats and balls are subjected to a machining of the treated areas to obtain a high degree of finishing (0.2) to reach the degree of thickness required and then move to the seating of the seats with the ball.
Additional laboratory tests can be carried out according to the technical specifications of the projects.