The worm gear flange butterfly valve (also known as the worm gear flange flap valve) is a simple regulating valve, mainly used for on/off control and flow regulation of low-pressure pipeline media. It is suitable for conveying corrosive or non-corrosive fluids in engineering systems such as coal gas, natural gas, chemical smelting, power generation, and environmental protection.
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Worm Gear Flanged Butterfly Valve Technical parameters
Size Range: 2″ to 48″ (DN50-DN1200)
Material: Carbon Steel, Stainless Steel
Connection Options: Flanged
Working Pressure:Up to 300 psi (20.7 bar)
Working Temperature: -29°C to 425°C
Sealing Options: EPDM, PTFE, NBR, FKM
Manufacturing Method: Cast, Forged, Machined
Applicable Medium: Water, Oil, Gas, Air, Chemical Fluids
Manufacturing Standard: API 609, ASME B16.47, BS EN 593, ISO 5752
Worm Gear Flanged Butterfly Valve Structural Features
Worn Gear Drive Mechanism:
The worm gear reducer drives the valve stem to rotate, enabling the butterfly plate to rotate 0°~90° for opening and closing. It has a large transmission ratio (typically 15:1 to 60:1), low operating torque, and is easy to operate, making it especially suitable for manual control of large-diameter valves. The worm gear drive has a self-locking function; when the handwheel is stopped, the butterfly plate position remains stable, preventing the medium pressure from causing it to rotate on its own and ensuring system safety.
Flanged Connection Design:
The valve has flanges at both ends, which are directly bolted to the pipe flanges. This allows for convenient installation, good sealing, and is suitable for high-pressure, large-diameter pipelines. Compared to wafer-type butterfly valves, flanged connections are more robust, and maintenance does not require disassembling the entire pipeline system.
Butterfly Plate Structure:
A disc-shaped butterfly plate is used as the opening and closing element. The streamlined design reduces fluid resistance and energy consumption. Based on sealing method, seals can be categorized as follows:
Soft Seal: The sealing ring uses elastic materials such as nitrile rubber and fluororubber, embedded around the valve body or butterfly plate. It offers excellent sealing performance (up to zero leakage), but has limited temperature resistance (nitrile rubber: -40℃～90℃; fluororubber: -20℃～200℃).
Metal Seal: The sealing ring uses metal materials such as stainless steel and cobalt-based alloys. It is heat-resistant (up to 815℃), wear-resistant, and has a long service life, but its sealing performance is slightly inferior to soft seals.
Eccentric Design
Single Eccentric Structure: The valve stem centerline is offset from the butterfly plate center, reducing opening and closing friction and extending the sealing ring's lifespan.
Double Eccentric Structure: An angular eccentricity is added to the single eccentric structure, creating a cam effect to achieve a "tighter as it closes" sealing function.
Triple Eccentric Structure: Utilizes the cam effect to completely eliminate friction between the valve seat and the sealing ring during the 90-degree stroke. Suitable for high-temperature and high-pressure conditions, it offers excellent sealing performance.
Worm Gear Flanged Butterfly Valve Specification Parameters
| ITEM | PN 0.6 | PN 1.0 | PN 1.6 | PN 2.5 | PN 4.0 |
|---|---|---|---|---|---|
| Nominal Size DN (mm) | 50–2000 | 50–2000 | 50–2000 | 50–2000 | 50–500 |
| Nominal Pressure (MPa) | 0.6 | 1.0 | 1.6 | 2.5 | 4.0 |
| Strength Test Pressure (MPa) | 0.9 | 1.5 | 2.4 | 3.75 | 6.0 |
| Seal Test Pressure (MPa) | 0.66 | 1.1 | 1.76 | 2.75 | 4.4 |
| Gas Seal Test Pressure (MPa) | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 |
| Leakage | < 0.1 × DN mm³/s (GB/T 13927-92) | ||||
| Suitable Temperature | −29 ~ 425°C (Carbon steel) / −40 ~ 550°C (SS / Cr-Mo) | ||||
| Applicable Medium | Air, water, steam, gas, oil, acid, alkali, salt with weak corrosive media | ||||
| Drive Type | Worm gear / Electric | ||||
Worm Gear Flanged Butterfly Valve Standard
| ITEM | STANDARD |
|---|---|
| Manufacturing Standard | JB/T 8527-97 |
| Flange Standard | GB 9113 |
| Face-to-Face Standard | GB 12221-89 |
| Test Standard | GB/T 13927-92 |
Worm Gear Flanged Butterfly Valve Main Components Material:
| PART NAME | MATERIAL |
|---|---|
| Body | Carbon steel, stainless steel, chrome molybdenum steel, alloy steel |
| Disc | Carbon steel, alloy steel, stainless steel, chrome molybdenum steel |
| Seat Ring | Stainless steel and high-temperature asbestos combined into multi-layer |
| Stem | 2Cr13, 1Cr13 stainless steel, chrome molybdenum steel |
| Bearing | Austenitic stainless steel, 304 nitrided |
| Packing | Flexible graphite |
Worm Gear Flanged Butterfly Valve Applications
Metallurgical Industry: Used in gas recovery systems for steelmaking converters, high-temperature molten metal conveying pipelines, etc., to control the on/off state and flow rate of high-temperature gases or liquids.
Power Industry: Suitable for boiler feedwater systems, steam systems, cooling water systems, etc., in thermal power plants and nuclear power plants, to regulate medium flow rate and pressure.
Petrochemical Industry: Handles various chemical media, such as acid and alkali solution conveying pipelines, pulp conveying pipelines, etc., adaptable to corrosive environments.
Water Supply and Drainage Systems: Controls the on/off state and regulates flow rate in urban water supply and drainage pipelines, such as residential water supply pipelines, sludge conveying pipelines in sewage treatment plants, etc.
HVAC: Controls the flow rate and direction of media in chilled water and cooling water pipelines of central air conditioning systems, regulating system temperature and pressure.
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