Guide to Electric Butterfly Valve Commissioning & Operation

Electric butterfly valves are widely used in pipeline systems as shut-off valves and control valves, with their operation controlled by electrical signals. These valves are equipped with manual operation devices to ensure that they can still be manually operated in the event of a power failure, thereby avoiding any impact on the normal operation of the system. To ensure the correct installation and efficient operation of electric butterfly valves, the following detailed commissioning and operation steps are provided.

Pre-Commissioning Preparations

Before starting the commissioning process, first adjust the butterfly valve to the mid-position and connect the power and control power supplies. Ensure that the electric actuator's forward and reverse rotations are correctly set. If the valve is equipped with a bypass valve, open the bypass valve before starting. Follow the manufacturer's installation instructions to correctly install the electric butterfly valve and set a stable foundation to ensure the valve's operational stability.

Mechanical Connection Commissioning

Mechanical connection commissioning is a critical step to ensure the normal operation of the valve. First, adjust the butterfly valve to the fully open position, then tighten the gasket and bolts of the flange. Ensure that the connection between the electric actuator and the valve stem is concentric to avoid failures caused by misalignment. When tightening the bolts, apply even force to avoid over-tightening or loosening.

Electrical Commissioning

Electrical commissioning primarily checks the coordination between the electric actuator and the valve's control system. Ensure that the micro-switch limits of the electric actuator correspond to the mechanical switch positions of the butterfly valve. If discrepancies are found, adjust the limit stops according to the actuator's manual to ensure that the limit switch travel matches the valve's mechanical action. During electrical commissioning, the system will indicate the valve's open/close status via a display.

Commissioning Steps

Limit Switch Adjustment: Check the micro-switch of the electric actuator to ensure its travel matches the mechanical switch positions of the butterfly valve. Adjust the limit stops if deviations are found.

Status Display: Under normal automatic control, the system will display the current valve position as a percentage. Indicator lights will illuminate when the valve opens or closes, indicating status changes.

Types of Electric Actuators and Control Methods

Electric butterfly valve actuators can be categorized based on their control methods.

On/Off Type: Controls the valve's open/close state via a switch circuit, outputting a voltage signal to indicate fully open or fully closed states.

Passive Contact Type (S-Type): Controls the valve's open/close state via a switch circuit, outputting a passive contact signal to indicate fully open or fully closed states.

Open Signal Type (R-Type): Controls the valve's open/close state via a switch circuit, outputting a resistance signal corresponding to the valve's position during operation.

Intelligent Regulating Type (Z-Type): Achieves intelligent control by receiving external control signals (e.g., 0-10V, 4-20mA) and ensures precise valve position control through feedback signals.

Power and Control System Inspection

Ensure the electric butterfly valve's power supply is correctly connected. The 380V power supply should be within ±10% of the rated voltage, with a three-phase voltage imbalance not exceeding 5%. Use a multimeter to check the power supply voltage, ensuring no loose or false connections, and that the insulation of the power cables is intact. When inspecting electrical wiring, confirm that the electrical schematic matches the actual wiring, and check the connections of contactors, relays, and limit switches. Key Inspection Items including:

Power Voltage Check: Use a multimeter to confirm the 380V power supply voltage is within the required range.

Circuit Connection Check: Verify the electrical schematic to ensure correct wiring.

Fuses and Circuit Breakers: Check that fuses are intact and that the rated current meets circuit requirements.

Insulation Resistance Test: Use a megohmmeter to check the insulation resistance of the electrical circuits, ensuring it is not less than 1MΩ.

Motor Rotation and Parameter Settings

Before connecting the electric butterfly valve to the pipeline, power on the system and briefly start the motor to observe its rotation direction. If the motor rotates incorrectly, immediately cut the power and adjust the motor's phase sequence. Set the controller parameters according to system requirements, such as open/close times, control methods (remote or local control), and protection parameters (e.g., overcurrent protection, overheating protection).

Manual and Remote Control Commissioning

During commissioning, manually operate the electric butterfly valve's open/close functions using the control box buttons, observing whether the valve operates smoothly and whether the controller's displayed status matches the valve's actual state. If the device supports remote control, use remote control equipment to send commands, checking the valve's responsiveness and the smoothness of switching between remote and local control.

Installation Inspection and Adjustment

During installation, ensure the electric butterfly valve is correctly positioned, with the valve's central axis aligned with the pipeline's central axis, with deviations not exceeding specified limits. Also, check that the flange connection bolts are evenly tightened, ensuring the tightening torque meets installation requirements to prevent installation stress from affecting the valve's normal operation. Important Inspection Items include:

Valve Center Alignment: Ensure the valve's central axis aligns with the pipeline's central axis.

Flange Connection Check: Inspect the tightening of flange connection bolts, ensuring even tightening.

Limit Switch Adjustment

Electric butterfly valves are typically equipped with open and close limit switches to ensure the valve stops accurately at fully open and fully closed positions. Adjust the limit switches based on the valve's actual movement to ensure they precisely cut off the motor power, preventing over-opening or over-closing.

Static Seal Performance Test

Perform a static seal test before introducing media into the pipeline. After closing the valve, inject a certain amount of water or air on one side and observe the other side for leaks. If leaks are found, inspect the sealing surfaces for impurities, damage, or deformation, and clean, repair, or replace the seals as necessary.

Operation Test and Final Inspection

After commissioning, conduct multiple open/close cycle tests on the valve, observing its operation, including motor noise, action speed, limit switch accuracy, and sealing performance. Ensure no abnormal vibrations, noises, or overheating occur during operation. If abnormalities are detected, immediately stop the system and inspect and resolve the issue. Operation Test Key Points are in the following:

Motor Operation Check: Inspect the motor for abnormal noises.

Valve Action Check: Ensure the valve operates smoothly without sticking during opening and closing.

Sealing Performance: Confirm the valve is leak-free under working pressure.

Conclusion

The commissioning of electric butterfly valves requires meticulous operation, with each step undergoing strict inspection to ensure stable and long-term valve operation. Through precise mechanical and electrical commissioning, electric butterfly valves can accurately control flow under various working conditions, providing efficient control solutions for a wide range of pipeline systems.