Xiamen Dervos Valves Industry Co., Ltd

Extraordinary Suppliers of Forged Valves in China

Home > News > Content
Special Ball Valve Need To Improve The Two Major Performance
- Jul 06, 2017 -

For metal hard sealed ball valve, it is necessary to improve its wear resistance and sealing.

Spherical and seat surface hardening treatment

As the special ball valve used in high temperature, high pressure, the media contains solid particles of the working conditions, therefore, must use metal hard sealed ball valve. General ball valve matrix is generally carbon steel, stainless steel or duplex steel and other metal materials, this metal material itself does not have wear resistance, must be sprayed on the entire surface of a coating, the material for the tungsten carbide, tungsten carbide cobalt chromium , Nickel-based alloy, chromium carbide, etc., after spraying the hardness of the sealing surface can reach HRC60 ~ HRC70.

In addition, the coating material and the matrix material of the binding force is very good, or use a period of time the coating may fall off, by improving the spraying technology, wear-resistant powder layer and the matrix material can get a higher binding force and higher density So that it also has better wear resistance and corrosion resistance, so as to ensure the service life.


For the special ball valve, the sealing performance is directly related to the service life of the valve, especially in the high pressure differential conditions, if the valve there is a certain amount of leakage in the valve leakage site is easy to high-speed flow of media scouring, resulting in greater Leakage, and ultimately cause the valve failure. Sphere and valve seat and the seal between the valve seat and the valve body is essential, the sealing material is generally graphite, graphite compression range and the required compression force is generally larger, while the spring is also very critical. Like coal chemical, coal slurry delivery, can not let the slurry into the valve seat and the valve cover of the sealed area, otherwise it will cause the hardening of graphite, reducing the sealing effect, if the impurities into the spring card inside, the spring can not be effective stretching, Provide the necessary preload, thus affecting the sealing performance. Now the ball valve application of the various parameters (such as temperature, pressure, etc.) is getting higher and higher, like the application of coal chemical ball valve can reach 900LB the highest level, temperature 300 ℃ ~ 400 ℃, in this high temperature and pressure, And the packing area of the sealing requirements are relatively high.

Hard sealing ball valve main technical difficulties in wear, life, sealing, torque control and other aspects. Wear-resistant in the ball valve seat sealing surface, bearings and so on. In addition to spraying process, other aspects such as different parts of the material selection, hard seal ball valve bearings also require wear.