HEP valve positioner
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I would like to ask the more experienced colleagues how to adjust the feedback of this valve positioner. I tried to do it according to the instructions, but it doesn’t seem to work properly; the situation is getting worse, and it’s also impossible to return it to its original state before any adjustments were made. Does anyone know how to do this? Please provide me with a step-by-step guide
1. First, check the debugging conditions: whether the air pressure is appropriate (usually spring pressure +0.05)； Check the throttle hole for any blockages ； Is the coil engagement distance appropriate? ； 2. Adjust zero point – positions 0/25%, 50%, 75%, 100% ； 3. Insufficient travel – loosen the travel screw and increase it ； Zero out again, repeat 2 ； 4. 50% is too high; 100% means full open – indicating a large travel distance ； Loosen the adjustment screw and reduce it ； Zero out again, repeat 2 ； 5、OK
1. Check the pressure relief valve; ensure that the air pressure is within the acceptable range. Press the valve stem in the upper right corner – the valve should open fully. Release it, then pull the pulley upward; the pressure output indicator should respond. Keep the pressure between 0 and 1.
2. Send a 12mA signal from the control room to check whether the valve is open halfway. If not, adjust the travel distance using the adjustment screw so that the valve is in a half-open position when a 12mA signal is sent.
3. Begin testing the circuit board: send a 4mA signal from the control room. Hold down the SET button for three seconds; if the green light comes on, check whether the control room is receiving a 4mA signal. If not, adjust it using the + and – buttons until it reaches 4mA. Wait for three seconds of stability, then press the SET button once – the green light should flash once, indicating success. Next, send an 8mA signal from the control room and check whether the feedback signal is 8mA. If not, adjust it using the + and – buttons again, then press the SET button once; the green light should flash once again. Repeat this process for 12mA, 16mA, and 20mA. When reaching 20mA, pressing the SET button will cause the green light to flash continuously, indicating that the adjustments are complete.
2. Send a 12mA signal from the control room to check whether the valve is open halfway. If not, adjust the travel distance using the adjustment screw so that the valve is in a half-open position when a 12mA signal is sent.
3. Begin testing the circuit board: send a 4mA signal from the control room. Hold down the SET button for three seconds; if the green light comes on, check whether the control room is receiving a 4mA signal. If not, adjust it using the + and – buttons until it reaches 4mA. Wait for three seconds of stability, then press the SET button once – the green light should flash once, indicating success. Next, send an 8mA signal from the control room and check whether the feedback signal is 8mA. If not, adjust it using the + and – buttons again, then press the SET button once; the green light should flash once again. Repeat this process for 12mA, 16mA, and 20mA. When reaching 20mA, pressing the SET button will cause the green light to flash continuously, indicating that the adjustments are complete.
It’s the step of pressing ‘set’ after making the adjustments – the green light doesn’t turn on, as if the changes can’t be saved. What could be the reason?