The main performance indicators of the electric control valve are: basic error, return difference, dead zone, rated stroke deviation, leakage, tightness, compressive strength, appearance, rated flow coefficient, inherent flow characteristics, vibration resistance, temperature, long-term working reliability , Explosion-proof, damping characteristics, influence of power supply voltage change, influence of environmental temperature change, insulation resistance, insulation strength, etc. The requirements and test methods of the first 10 indicators are the same as or similar to those of pneumatic valves. The basic error, hysteresis, dead zone, leakage, sealing, appearance, damping characteristics, influence of power supply voltage changes, and insulation resistance are the factory test items. The requirements and test methods for the three performance indicators are: 1) Damping characteristics The damping characteristics of the electric control valve are stipulated that the valve stem does not exceed 3 "half-cycle" swings in the forward and reverse stroke directions. The test method is to add signals of 20%, 50%, and 80% of the input signal range value to the input terminal, and observe the number of "half cycle" swings of the valve stem at the corresponding positions of the forward and reverse strokes. 2) The change of power supply voltage affects when the power supply voltage of the electric control valve changes within the range of 220 to 20-30V, the displacement change value of the valve stem should not exceed 1.5% of the full stroke. The test method is when the power supply voltage is 220V, add a signal of 20% of the signal range value to the input to measure the corresponding valve stem stroke value, then adjust the power supply voltage to 190V and 240V, and measure the corresponding valve stem stroke change value . Then add signals of 50% and 80% of the signal range value in turn, and measure the change value of the valve stem stroke. 3) Insulation resistance When the ambient temperature is 10～35℃ and the relative humidity does not exceed 85%, the insulation resistance of the electric control valve should meet the following requirements: each input terminal to the chassis is not less than 20MΩ; each input terminal to the power terminal is not less than 50MΩ; the power terminal to the chassis is not less than 50MΩ. The test method is to use a 500-type megohmmeter to test.
