Electric control valve has been widely used in various industrial control systems because of its high control precision, convenient installation and debugging. However, during use, there are also some problems that plague the on-site instrument personnel, which is the internal leakage problem of the valve. Here, we will discuss the common causes of leakage and solutions to the electric control valve, hoping to help the factory site maintenance personnel.
1. The zero setting of the actuator is inaccurate and does not reach the fully closed position of the valve. Adjustment method: 1) Manually close the valve (must confirm that it has been completely closed); 2) Manually close the valve again, and use a slight pressure to stop it; 3) Twist again (open the valve) half a turn; 4) Then adjust the limit.
2, the valve is pushed down to close the type, the thrust of the actuator is not large enough, when there is no pressure, the debugging is very easy to reach the fully closed position, and when there is a lower thrust, the thrust of the liquid cannot be overcome, so the shutoff is not in place. Solution: Replace the high-thrust actuator or the balanced spool to reduce the media imbalance force.
3, the internal control valve manufacturing quality caused by internal leakage valve manufacturers in the production process of the valve material, processing technology, assembly process and other strict control, resulting in unqualified sealing surface grinding, pitting, trachoma and other defects of the product is not complete Excluding, caused the inner leakage of the electric control valve. Solution: Rework the sealing surface.
4, the electric control valve control part affects the internal leakage of the valve The traditional control method of the electric control valve is through the valve limit switch, over torque switch and other mechanical control methods, because these control elements are affected by the ambient temperature, pressure, humidity, resulting in Inaccurate positioning of the valve, spring fatigue, non-uniform thermal expansion coefficient and other objective factors, resulting in internal leakage of the electric control valve. Solution: Readjust the limit.
5. The inner leakage caused by the debugging problem of the electric control valve is influenced by the processing and assembly process. The electric control valve generally has the phenomenon of electric opening after manual closing, such as the operation position of the upper and lower limit switches, the stroke of the electric control valve. If the adjustment is smaller, then there is an unsatisfactory state in which the electric control valve is not closed tightly or the valve is not open; the adjustment of the stroke of the electric control valve is larger, then the over-torque switch protection action is caused; if the action value of the over-torque switch is adjusted, Larger, there was an accident that crashed the transmission mechanism or crashed the valve and even burned the motor. In order to solve this problem, usually, when the electric regulating valve is commissioned, the electric regulating valve is manually shaken in the end, and then it is shaken in the opening direction, the lower limit switch position of the electric door is set, and then the electric control valve is opened to the full open position. Switch position, so that the electric control valve does not appear after the manual closed after the phenomenon of electric open, in order to make the electric door open and close freely, but virtually caused by the internal leakage of the electric door. Even if the adjustment of the electric control valve is more ideal, because the limit switch's operating position is relatively fixed, the valve control of the medium in the operation of the valve constantly scouring, wear, will also cause the valve to close the leakage caused by lax phenomenon. Solution: Readjust the limit.
6, selection error caused by the valve cavitation corrosion caused by the electric control valve internal leakage cavitation and pressure difference, when the valve's actual pressure difference â–³ P greater than the critical pressure difference â–³ Pc generating cavitation, it produces cavitation, empty In the course of the cracking process, a huge amount of energy is released when the bubble bursts, which has a great destructive effect on the throttling elements such as the valve seat and the valve core. The general valve operates for up to three months or even shorter under cavitation conditions, ie, the valve is subjected to Severe cavitation erosion, resulting in valve seat leakage rate up to 30% of the rated flow, this is irreparable, so different uses of electric doors have different specific technical requirements, according to the system process to a reasonable choice Electric control valve is very important. Solution: process improvement, use multi-stage buck or sleeve control valve.
7, the media erosion, electric valve caused by the aging of the internal leakage of the electric control valve is adjusted after a certain period of time after the operation, due to the valve cavitation and medium erosion, valve core and valve seat wear, internal parts aging and other reasons, There will be a large motorized valve travel, the electric control valve is not strictly closed, resulting in increased leakage of the electric control valve, with the passage of time, the electric valve leakage phenomenon will become more and more serious. Solution: Re-adjust the actuator and perform regular maintenance and calibration.
1. The zero setting of the actuator is inaccurate and does not reach the fully closed position of the valve. Adjustment method: 1) Manually close the valve (must confirm that it has been completely closed); 2) Manually close the valve again, and use a slight pressure to stop it; 3) Twist again (open the valve) half a turn; 4) Then adjust the limit.
2, the valve is pushed down to close the type, the thrust of the actuator is not large enough, when there is no pressure, the debugging is very easy to reach the fully closed position, and when there is a lower thrust, the thrust of the liquid cannot be overcome, so the shutoff is not in place. Solution: Replace the high-thrust actuator or the balanced spool to reduce the media imbalance force.
3, the internal control valve manufacturing quality caused by internal leakage valve manufacturers in the production process of the valve material, processing technology, assembly process and other strict control, resulting in unqualified sealing surface grinding, pitting, trachoma and other defects of the product is not complete Excluding, caused the inner leakage of the electric control valve. Solution: Rework the sealing surface.
4, the electric control valve control part affects the internal leakage of the valve The traditional control method of the electric control valve is through the valve limit switch, over torque switch and other mechanical control methods, because these control elements are affected by the ambient temperature, pressure, humidity, resulting in Inaccurate positioning of the valve, spring fatigue, non-uniform thermal expansion coefficient and other objective factors, resulting in internal leakage of the electric control valve. Solution: Readjust the limit.
5. The inner leakage caused by the debugging problem of the electric control valve is influenced by the processing and assembly process. The electric control valve generally has the phenomenon of electric opening after manual closing, such as the operation position of the upper and lower limit switches, the stroke of the electric control valve. If the adjustment is smaller, then there is an unsatisfactory state in which the electric control valve is not closed tightly or the valve is not open; the adjustment of the stroke of the electric control valve is larger, then the over-torque switch protection action is caused; if the action value of the over-torque switch is adjusted, Larger, there was an accident that crashed the transmission mechanism or crashed the valve and even burned the motor. In order to solve this problem, usually, when the electric regulating valve is commissioned, the electric regulating valve is manually shaken in the end, and then it is shaken in the opening direction, the lower limit switch position of the electric door is set, and then the electric control valve is opened to the full open position. Switch position, so that the electric control valve does not appear after the manual closed after the phenomenon of electric open, in order to make the electric door open and close freely, but virtually caused by the internal leakage of the electric door. Even if the adjustment of the electric control valve is more ideal, because the limit switch's operating position is relatively fixed, the valve control of the medium in the operation of the valve constantly scouring, wear, will also cause the valve to close the leakage caused by lax phenomenon. Solution: Readjust the limit.
6, selection error caused by the valve cavitation corrosion caused by the electric control valve internal leakage cavitation and pressure difference, when the valve's actual pressure difference â–³ P greater than the critical pressure difference â–³ Pc generating cavitation, it produces cavitation, empty In the course of the cracking process, a huge amount of energy is released when the bubble bursts, which has a great destructive effect on the throttling elements such as the valve seat and the valve core. The general valve operates for up to three months or even shorter under cavitation conditions, ie, the valve is subjected to Severe cavitation erosion, resulting in valve seat leakage rate up to 30% of the rated flow, this is irreparable, so different uses of electric doors have different specific technical requirements, according to the system process to a reasonable choice Electric control valve is very important. Solution: process improvement, use multi-stage buck or sleeve control valve.
7, the media erosion, electric valve caused by the aging of the internal leakage of the electric control valve is adjusted after a certain period of time after the operation, due to the valve cavitation and medium erosion, valve core and valve seat wear, internal parts aging and other reasons, There will be a large motorized valve travel, the electric control valve is not strictly closed, resulting in increased leakage of the electric control valve, with the passage of time, the electric valve leakage phenomenon will become more and more serious. Solution: Re-adjust the actuator and perform regular maintenance and calibration.
High Resistance Electric Heating Alloy
High resistance electric heating alloy is a conductive material used to manufacture resistance elements, which can be used to manufacture heating elements in various resistance heating equipment. The high-resistance electric heating alloys produced by Seonjip are mainly used in electronic components and heating elements of electric heating equipment.
Alloy Wire,Nichrome Wire,Resistance Heating Wire,Nichrome Resistance Wire
Jiangsu Seonjip Technology Co.,Ltd. , https://www.seonjip.com