Electric forged steel ball valve has been more and more widely used in various industrial control systems due to their high control accuracy and convenient installation and debugging. However, in the process of use, there are also some problems that plague the on-site installation and debugging personnel, that is, the problem of internal leakage of the valve. Here we will discuss the common internal leakage causes and solutions of electric forged steel ball valves, hoping to help the on-site maintenance personnel of the factory.
Ⅰ. The inaccurate zero position setting of the electric forged steel ball valve actuator
Adjustment method:
- 1. Manually close the valve (it must be confirmed that it has been completely closed);
- 2. Manually close the valve again with a little force, whichever is the case;
- 3. Screw it back (in the direction of valve opening) for half a turn;
- 4. Then adjust the limit;
Ⅱ. Selection of stroke mode of electric forged steel ball valve
The valve is opened and closed by rotating 90°. The torque of the actuator is not large enough, so it is easy to reach the full closed position when commissioning without pressure. When there is a rotating force, it cannot overcome the thrust pushed by the liquid, so the closing is not in place.
Solution: Replace the actuator with high thrust, or replace it with a balanced spool to reduce the unbalanced force of the medium.
Ⅲ. Internal leakage caused by the manufacturing quality of electric forged steel ball valve
Forged steel valve manufacturers do not strictly control valve material, processing technology, assembly technology, etc. in the production process, resulting in unqualified sealing surface grinding, and the products with defects such as pitting and trachoma are not completely eliminated, resulting in the electric forged steel ball valve. leak.
Solution: Rework the sealing surface.
Ⅳ. The control part of the electric forged steel ball valve affects the internal leakage of the valve
The traditional control method of electric forged steel ball valve is through the valve limit switch, over-torque switch and other mechanical control methods. Because these control components are affected by the ambient temperature, pressure and humidity, it will cause valve positioning inaccuracy, spring fatigue, thermal expansion coefficient unevenness and other objective factors, then cause internal leakage of the electric forged steel ball valve.
Solution: Readjust the limit.
Ⅴ. Internal leakage caused by debugging problems of electric forged steel ball valve
Affected by the processing and assembly process, the electric forged steel ball valve generally has the phenomenon that the electric forged steel ball valve cannot be opened electrically after being closed manually. If the stroke of the electric control valve is adjusted smaller by the action position of the upper and lower limit switches, the electric control valve will not be closed tightly or the valve will not be opened. Adjusting the stroke of the electric forged steel ball valve larger will cause the over-torque switch protection action. If the action value of the over-torque switch is adjusted to be larger, there will be accidents such as hitting the deceleration transmission mechanism or hitting the valve, or even burning the motor.
In order to solve this problem, you can manually shake the electric control valve to the end when debugging the electric control valve, then shake it to the lower limit switch position of the fixed electric door in the opening direction, and then open the electric forged steel ball valve to the fully open position to set the upper limit switch location. In this way, the electric forged steel ball valve will not have the phenomenon that the electric forged steel ball valve cannot be opened by the electric power after being manually closed, so that the electric forged steel ball valve can be opened and closed freely, but it will cause the electric forged steel ball valve to leak.
Since the action position of the limit switch is relatively fixed, the continuous scouring and wear of the valve by the medium controlled by the valve during operation will also cause internal leakage caused by the valve being closed loosely, even if the electric control valve is adjusted ideally .
Solution: Readjust the limit.
