PNEUMATIC WAFER BUTTERFLY VALVE
HANDWHEEL
The handwheel is the key to the safety redundancy design of pneumatic actuators. Its reasonable use can significantly improve the reliability of the system. During operation, the "pressure relief → switching mode → operation → reset" process must be strictly followed, and regular maintenance must be performed to ensure normal function. For key process valves, it is recommended to conduct handwheel operation training and formulate emergency plans.
1. Manual operation (emergency/maintenance mode)
Function description: When the pneumatic system fails (such as air source interruption, solenoid valve failure), the handwheel allows the operator to directly manually control the opening and closing of the valve to ensure the continuity of the process or emergency cut-off.
Operation method: It is necessary to switch to manual mode (some models require pressing the clutch or disengaging the pneumatic connection) and drive the valve stem by rotating the handwheel.
Applicable scenarios: factory emergency shutdown, key valve control during air source maintenance.
2. Handwheel type and working mode
Direct-connected handwheel (direct drive): Structure: The handwheel is directly mechanically connected to the valve stem, without switching the air path.
Features: The structure is simple, but the internal resistance of the pneumatic actuator (such as spring reset force) must be overcome during operation, and a large torque may be required.
Note: Before operation, it is necessary to confirm that the system has been depressurized to avoid damage to components during load operation.
Bypass handwheel (air circuit isolation):
Structure: Equipped with a bypass valve, the air source passage must be closed before operation to cut off the connection between the actuator and the air source.
Features: More labor-saving operation, high safety, suitable for high-pressure or large-diameter valves.
Steps: Close the gas source → Open the bypass valve to release pressure → Turn the handwheel to operate.
3. Safety locking function
Valve position locking: The handwheel is often equipped with a mechanical lock hole or locking pin, which can fix the valve in a specific position (such as fully open/fully closed) to prevent misoperation.
Application scenario: Ensure the stability of the valve state during equipment maintenance and long-term outage.
4. Calibration and debugging
Valve stroke calibration: When installing or replacing the actuator, fine-tune the valve to the middle or extreme position through the handwheel, which is synchronized with the actuator stroke.
Signal feedback calibration: Adjust the valve position in manual mode and calibrate the 4-20mA signal feedback with the positioner.
TECHNICAL PARAMETERS
Item Pneumatic butterfly valve
Nominal diameter DN50-DN1200
Pressure level PN10-PN40 (ANSI 150LB-300LB optional)
Valve body material WCB, CF8, CF8M, duplex steel, etc.
Seal material EPDM, NBR, PTFE, metal seal
Air source pressure 0.4-0.7MPa
Applicable media Water, steam, oil, gas, particulate matter
FEATURES
Quick response
Pneumatic drive, opening and closing actions are completed within 0.5-2 seconds, meeting the needs of automatic control.
High sealing
Pneumatic drive, opening and closing actions are completed within 0.5-2 seconds, meeting the needs of automatic control.
Pressure and temperature resistance
The valve body material can be cast iron, cast steel, stainless steel, etc. The pressure range is PN10-PN40 and the applicable temperature is -29C~200C.
Lightweight design
Wafer installation does not require flanges, saving space and reducing the load on the piping system.
OVERVIEW
Pneumatic wafer butterfly valve is an industrial valve driven by pneumatic actuator. It can be quickly installed in the pipeline through wafer connection. It is widely used in flow regulation and cut-off control of liquid, gas and dust media. It has compact structure, fast opening and closing, reliable sealing, and is an ideal choice for petrochemical, electric power, metallurgy, water treatment and other fields.
PRODUCT COMPOSITION
Pneumatic actuator:
Single acting (spring return) or double acting (bidirectional air control) optional.
Standard positioner and solenoid valve, support 4-20mA signal input, to achieve precise opening adjustment.
Bearings and connectors: low friction coefficient bearings ensure flexible rotation, clamp bolts meet ISO standards.
Pneumatic wafer butterfly valve
Consists of the following core components to ensure efficient and stable operation:
Valve body: precision casting, streamlined design to reduce medium resistance, corrosion resistance, high pressure resistance.
Valve plate: disc structure, surface covered with rubber or polytetrafluoroethylene (PTFE), to achieve bidirectional sealing.
Valve stem: high-strength stainless steel material, anti-fracture, anti-torsion, to ensure long service life.
Seal ring: EPDM, NBR or fluororubber material, suitable for different media conditions.
APPLICATIONS
Pneumatic soft seal wafer butterfly valves are widely used in HVAC systems, water treatment plants, food and pharmaceutical production, chemical industry, and environmental protection systems to control the flow of fluids (including liquids, gases, and solid particle media) and regulate flow.
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