Double Actuator Worm Gear Pneumatic Wafer Butterfly Valve

1. Structure of Double Actuator Butterfly Valve

• Pneumatic Actuator: Uses compressed air to open or close the valve automatically.
• Worm Gear Operator: A manual gearbox with a handwheel that allows manual valve operation.
• Switching Mechanism / Declutch Device: Allows switching between pneumatic control and manual worm gear operation.
• Wafer Butterfly Valve Body: Installed between two pipe flanges. The wafer design is compact and cost-effective.

2. Advantage of Double Actuator Butterfly Valve:

• Ensures valve operation even during air supply failure.
• Critical pipelines can still be controlled manually.
• Suitable for automatic + emergency manual operation.
• Worm gear provides large torque multiplication, useful for larger valves.

3. Working Principle of Pneumatic & Worm Gear Butterfly Valve

Pneumatic Operation (Primary Mode)

• Compressed air enters the pneumatic actuator.

• The actuator rotates the valve stem 90°, opening or closing the butterfly valve.

• Used in automated systems or remote control pipelines.

Manual Operation (Backup Mode)

• If air pressure fails, the operator engages the worm gear.

• The handwheel rotates the worm shaft.

• The worm gear drives the valve stem and disc to open or close.

Material

Part Name	Material/Method
Body	Ductile Iron, Casting Iron, WCB, LCB/LCC, Stainless Steel, Duplex Stainless Steel, Aluminium Bronze
Disc	Ductile Iron(Coated/Lined), WCB, LCB/LCC, Stainless Steel, Duplex Stainless Steel, Aluminium Bronze
Seat	Rubber(EPDM/NBR/VITON), Nature Rubber, Silicon Rubber, PU, HNBR, Hypalon
Stem	304, 316, 420(2Cr13), 431, 1.4462, 17-4PH, Monel
Actuator	Pneumatic, Handlever, Worm Gear, Electric

Technical Parameters

ITEM	Standard
Design	EN593 | API609
Face to Face	EN558 | ISO5752 | API608 | BS5155-4
Top Flange	ISO5211
Flange Drilling	PN6 | PN10 | PN16 | ASME B16.5 CL150 | JIS 10K
Pressure Rating	PN6 | PN10 | PN16 | PN25 | CL150 | JIS 10K
Tightness Test	ISO5208 | API598 | EN12266-1