TOP 7 Questions & Answers on Control Valve Positioner

Welcome to our latest YouTube video where we give the answers of top 7 questions of control valve positioner.
Control Valve Positioner's top 7 questions and its answers.
1. What is a control valve positioner, and why is it used?
Ans:A control valve positioner is a device mounted on a control valve that ensures the valve reaches the correct position according to the control signal. It is used to overcome issues like friction, pressure variations, or other resistances that can prevent the valve from moving to the desired position accurately.
2. What are the different types of control valve positioners?
The main types are:
Pneumatic positioners: Use air pressure for valve positioning.
Electropneumatic positioners: Convert an electrical signal to a pneumatic output.
Digital (Smart) positioners: Utilize microprocessors for precise control and diagnostics.
3. How do you calibrate a control valve positioner?
Calibration involves:
Sending a known input signal to the positioner.
Checking the valve stem position or the actuator movement.
Adjusting the positioner settings (zero and span) to match the input signal with the valve's position accurately.
4. Explain the function of the bypass switch on the valve positioner.
Ans: Signal bypass permits the control signal to be applied directly to diaphragm actuator as if there was no positioner. This
arrangement is designed to allow for actuator calibration with minimum inconvenience.
5.How do positioners improve valve performance?
Positioners enhance performance by:
Reducing hysteresis and dead time.
Ensuring precise positioning under varying load conditions.
Allowing faster and smoother valve response.
Providing diagnostics for predictive maintenance.
6. List 6 Advantages of using Positioners
1. Piston Actuator
2. Signal range change
3. Signal direction change
4. Positive Positioning
5. Increased speed of response
6. Signal Characterizing
7.What are common issues faced with control valve positioners?
Some common issues include:
Incorrect calibration leading to improper valve positioning.
Blockages in pneumatic lines.
Wear and tear of mechanical components.
Signal interference in digital positioners.