What are the main reasons for the damage of the sealing surface of the high-pressure ball valve during its use? Let Dervos introduce it to you!

1.  Mechanical Damage

During the opening and closing process, the sealing surface will be scratched, bumped, squeezed and other damages. The atoms between the two sealing surfaces penetrate each other under the action of high pressure, resulting in adhesion. When the two sealing surfaces move with each other, the adhesion is easily torn. The higher the surface roughness of the sealing surface, the easier this phenomenon occurs. During the opening and closing process of high pressure ball valve, the ball is in close contact with the valve seat, which will bruise the sealing surface, causing local wear or indentation on the sealing surface.

2.  Medium Erosion

When the medium moves at a high speed, it will directly flush the sealing surface, and the floating fine particles in the medium will collide with the sealing surface, causing local damage. When the medium is mixed and partially vaporized, bubble explosion will occur, which will impact the sealing surface and cause local damage. The alternating action of medium erosion and chemical erosion will strongly erode the sealing surface.

3.  Electrochemical Erosion

The potential difference will be caused by the contact between the sealing surfaces, the contact between the sealing surface and the enclosure and the valve body, as well as the concentration difference and oxygen concentration difference of the medium, resulting in the erosion of the sealing surface on the anode side.

4. Poor Sealing Surface Quality

(1) Improper selection of built-up welding and heat treatment specifications and poor operation during built-up welding and heat treatment lead to cracks, pores and slag inclusion on the sealing surface (For hard seal ball valve);

(2) Improper or wrong material selection leads to too high or too low hardness of sealing surface;

(3) The alloy composition of the sealing surface is diluted during the built-up welding of the valve seat or ball, it leads to not resistant to erosion and uneven hardness of the sealing surface.