Along with the wide application of pneumatic valves, pneumatic actuators technology is also in more and good, domestic and imported pneumatic actuators pneumatic actuators gap also more and more small, type more and more, now pneumatic actuators inspection method to do the following is introduced: a) prepare check and inspection 1 all test instrument shall be to shift to an earlier date 30 minutes electricity preheating; 2 test to meet the air pressure is 0.6 + /-0.1 Mpa; 3 actuators appearance without obvious damage, gas leading copper tube no obvious flat and assembly on firm; 4 position transmitter connection screw length for enforcement agencies must comply with the technical requirements of the model; Tighten the connecting rod shaft in the transmitter and connection screw should be made of a plane perpendicular to the plane; 2) inspection standard and method 1 will pneumatic actuators is fixed to the calibration on the stage, respectively through gas, and control gas source and displacement detection connecting rod; Will on the calibration instrument calibration accurate; 2 mechanical zero calibration: input 4 mA current signal (0%), control gas signal should be 0.02 Mpa, the cylinder piston stroke should be zero; If not for zero, but by adjusting the zero adjustment screw nuts on the zero (zero high tight nuts); Zero and range requires repeated to adjust; Zero to 1% or error; 3 mechanical full range calibration: input 20 mA current signal (100%), control gas signal should be 0.10 Mpa, the cylinder piston stroke should be upper limit; If not for upper limit, but through the adjustment of the above precision extension spring reasonable range to adjust range (range small pine, range above precision extension spring big tight above precision extension spring); Zero and range requires repeated to adjust; Full range error to 1% or; 4 mechanical range halfway point positioning: zero and the range have, enter 12 mA current signal (50%, 0.06 Mpa), adjust position transmitter link rod place, make the point at should keep and vertical plane; 5 all the trip deviation calibration: input control gas signal 0.02 Mpa (0%), then gradually increase the input signal 0.036 Mpa (20%), 0.052 Mpa (20%), and 0.068 Mpa (60%), and 0.084 Mpa (80%), and 0.1 Mpa (100%), make the cylinder piston go completely trip, all point to 1.5% or all deviation; 6, nonlinear deviation test: input control gas signal 0.02 Mpa (0%), then gradually increase the input signal until 0.10 Mpa (100%), again will signal drop is 0.02 Mpa (0%), make the actuators go completely trip, and record every 0.008 Mpa signal pressure increase or decrease of the corresponding trip value, the actual pressure ━ trip with the theoretical relationship between the nonlinear deviation to 1% or; 7 and later become poor trip test: and nonlinear deviation test method is same, positive and negative pressure ━ actual trip in the relationship, the same pressure value of the piston and cylinder under schedule of the values of the maximum difference to more than 1%; 8 sensitivity test: in the signal pressure were 0.03, 0.06, 0.09 Mpa trip place, increase and reduce pressure, test in the cylinder piston rod began to move to the age 0.1 mm signal pressure change value, the biggest change to 0.2% or; 9, the piston cylinder sealing testing: 0.5 Mpa pressure will access the cylinder of continuity of the room, and then cut off gas source, in points, 10 minutes in, in cylinder pressure drop value should be no more than 0.01 Mpa; 10 position transmitter electrical zero later detection: the opening location transmitter the bonnet and connected wire; Enter 12 mA current signal (0.06 Mpa), this time the adjustment in the transmitter eccentric circle, make its above the black thread and the circuit board on the white line alignment; And then enter 4 mA current (0.02 Mpa), this time can be adjusted in the transmitter zero output current is 4 potentiometer mA; Electrical zero error should be 1% or; 11 position transmitter electrical full range detection: input 20 mA current signal (0.1 Mpa), this time can be adjusted within the range transmitter output current for 20 potentiometer mA; Electrical full range error should be 1% or; 12 position feedback all current trip deviation calibration: input 4 mA current (0%), then gradually increase the input signal and mA current (25%), 12 mA current (50%), 16 mA current (75%), 20 mA current (100%), considering the linear displacement converted into the changes in the Angle of nonlinear error, 0%, 50%, 100% point feedback current error should be 1% or less, 25%, 75% point feedback current error should be 2% or; 13 position feedback current trip and become poor test: cylinder piston stroke with the worse is the same test method, practical and position feedback current ━ trip in the relationship, the same feedback current value of cylinders and pistons trip under the maximum difference in the value to more than 1%; 14 make calibration records, according to check the content on the record, item by item, fill in the form, inspection personnel must sign; 15 all finish after passing test, should be in position transmitter terminals inserted, tighten the back cover, then will the valve locator air entrance with plastic plug while blocking good; The later according to actual situation to decide whether detection
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