Replaceable Seat Gear Operated Metal Seated Easy Maintenance Long Service Life High Temp Butt Weld End Triple Offset Welded Butterfly Valve

Product Description

The Main Categories of This Valve The manual worm gear operated triple offset butterfly valve with butt weld ends is a high-performance isolation valve for zero-leakage severe service. Its triple eccentric geometry and metal-to-metal seat ensure bubble-tight shut-off, frictionless operation, and resistance to high temperature, pressure, and corrosion. Welded ends eliminate flange leak paths. The self-locking gear operator provides safe, effortless handwheel control with torque multiplication..
Catergory of Valve	Structural Classification	Connection	Operation Method	Other Addition	Remarks
Butterfly Valve	Triple Offset	Butt Weld	Worm Gear
The characteristics of each aspect are detailed in the following content.

Worm Gear Operated Triple Offset Butterfly Valve

Key Features

1. Triple offset geometry with metal-to-metal seating delivers zero leakage  Class VI), bi-directional shut-off, and frictionless cam action that minimizes seat wear.

2. Fully welded body with butt weld ends ensures permanent, leak-proof pipeline connection with reduced fugitive emission risks.

3. Self-locking worm gear manual operator provides effortless handwheel control, torque multiplication, mechanical stops, and clear position indication.

4. Broad material selection from carbon steel to duplex alloys and Stellite hardfacing supports services from -196°C cryogenic to 800°C high temperature.

5. Complies with APl 609, APl 607 fire-safe, ISO 15848, and NACE MR0175 for refinery, petrochemical, power, and LNG applications.

Specification of Basic Valve

Triple-offset butterfly valve

Triple-offset butterfly valve uses three geometric offsets (axial, radial, and angular cone axis) to enable rapid disengagement/engagement of the disc from the seat during operation, drastically reducing friction and wear while achieving near-zero leakage with metal-to-metal sealing. Compact, heatresistant, and highpressure capable, it offers long service life and low torque, making it ideal for demanding services in oil, chemical, and power industries.

Structural Characteristics

1) Axial offset: stem axis deviates from valve centerline, creating a cam effect during disc movement to reduce initial seating force.

2) Radial offset: stem axis deviates from pipe centerline, ensuring rapid disc seat separation during rotation, minimizing friction travel.

3) Angular (cone) offset: sealing cone axis is angled to the flow passage axis, enabling uniform wedging at closure and instant release at opening.

4) Metal hard sealing: laminated or solid metal to metal sealing pairs, no soft materials, resistant to high temperature, erosion, and corrosive media.

5) Bidirectional pressure capability: geometric design allows equal sealing performance in both flow directions, no mandatory installation orientation.

6) Flexible actuation: compatible with manual, pneumatic, electric, or hydraulic actuators, plus smart positioners and fieldbus, enabling remote modulation, on/off control, and seamless integration with DCS/PLC systems.

Technical Specifications (Custom configurations available upon request.)
Valve Body material	Carbon Steel WCB, A105, Stainless Steel SS304, SS316, SS316L, duplex steel 2205, 2507, Bronze C95400, C95800, etc.
Valve Disc material	Carbon Steel WCB, A105, Stainless Steel SS304, SS316, SS316L, duplex steel 2205, 2507, Bronze C95400, C95800, etc.
Valve Seat material	stainless steel, hard alloys, Inconel, Stellite, etc
Pressure Rating	PN0.6~PN6.3 MPa, or Class 150~Class 1500
Connecting Size	2"~96", DN50~DN2400 or larger
Connecting type	Flange, Wafer, Lug, Welded etc...
Applicable Temp	typically from cryogenic (e.g., -196°C) to high temperature (e.g., +600°C or up to +815°C), depending on materials
Applicable Medium	Water, Steam, Oil, Natural gas, etc
Sealing & Leakage Class	Metal-to-metal seating with bidirectional or unidirectional bubble-tight shut-off, up to Class VI per AP 598/ISO 5208.
Actuator & Accessories	Compatible with manual, pneumatic, electric, or hydraulic actuators, plus positioners, solenoid valves, limit switches, etc., for remote control and system integration
Design & Testing Standards	Conforming to 609, EN 593, ASME B16.34, AP 598, etc

Application

(1) Oil, Gas & Chemical: Used in long-distance crude oil and refined product pipelines, high-temperature catalytic cracking and hydrocracking in refineries, and handling corrosive fluids like acids, alkalis, and solvents.

(2) Power & Energy: Applied in boiler main steam and reheat steam lines in thermal plants, cooling systems in nuclear stations, gas turbine inlet/exhaust isolation, and district heating networks.

(3) Metallurgy, Mining & Pulp/Paper: Used in blast furnace gas lines, slurry transport, high-temperature caustic liquor in alumina production, and corrosive fluids in pulp cooking and bleaching stages.

(4) Cryogenic & Ultra-low Temperature Services: Suitable for LNG terminals, liquefied natural gas storage and transport systems, and air separation units handling liquid nitrogen/oxygen at -196°C.

(5) Marine & Offshore Engineering: Applied in ballast water systems, fuel oil transfer lines, bilge discharge, as well as flare vent and firewater systems on offshore platforms.

(6) High-pressure Gas & Storage Peak-shaving: Used in injection and production pipelines of underground natural gas storage facilities, compressed air energy storage systems, and high-pressure nitrogen/hydrogen transmission lines.

Connection of this Valve

The Connection of this Valve is Welded

1. Summary

    Valve ends are machined with weld preparation and joined to piping by welding — a permanent connection.
    Disassembly requires cutting the pipe; re-installation requires re-machining.
    Two types: Butt Weld (BW) and Socket Weld (SW).

 

2. Key Features  

  Advantages:

----Excellent sealing — zero leakage; no gasket aging or bolt loosening.
----Withstands high temperature and pressure; more reliable than flanged under severe conditions.
----No bolts or gaskets; compact and lightweight.
----High joint strength; suitable for vibration and pressure pulsation.

  Limitations:

   --Difficult to disassemble — requires cutting and re-machining.
   --Qualified welders required; quality depends on skill.
   --Welding heat may affect internal valve seals.
   --BW requires radiographic testing; SW only magnetic particle or dye penetrant testing.

3. Butt Weld (BW)
  Valve end and pipe end are butt-joined with a circumferential weld.
  Suitable for all sizes, pressures, and high-temperature service.
  Butt weld: uniform stress, good strength and fatigue performance.
  Radiographic testing possible; quality controllable.
  Applications: large-diameter piping, high-pressure/high-temperature service.

4. Socket Weld (SW)
  Generally for DN≤50 mm valves and piping.
  Thin-wall small-bore pipe prone to misalignment/burn-through in BW; SW more suitable.
  Internal crevice remains — not for crevice-corrosion-sensitive media or high-purity systems.
  Applications: small-bore, high-pressure small-bore piping.

5. International Standards

    EN 12627: Butt welding
    EN 12760: Socket welding ends
    EN 12982: BW end valves
    ASME B16.34: Valves 
    ASME B16.11: Forged fittings,
    APl Std 623: Steel Globe Valves
    MSS SP-72: Ball Valves
    MSS SP-110: Ball Valves

5. When to Select

Piping does not require frequent disassembly; valve operates reliably long-term.
Severe conditions: high temperature, high pressure, thermal cycling, or vibration.
Hazardous medium requiring extremely high leak-tightness.
Large diameter where flanged strength or sealing is insufficient.
Pipe material has good weldability and qualified welding conditions exist.
Not for:

Pipe section requires frequent inspection or valve replacement.
Valve material has poor weldability, or hot work is not permitted.
SW is not suitable for crevice-corrosion-sensitive media or high-purity piping.   

Operation of This Valve

The Operation of this Valve is Worm Gear Operation

Worm gear actuation converts high speed low torque input (from handwheel or motor) into low speed high torque output through a worm and wheel reducer to operate valves. Its key strengths are effort saving operation, self locking capability, compact design, and high reliability, making it ideal for medium to large diameter valves and applications requiring precise position holding.
 
Main Features
 
1. High Torque Output: Large gear ratio multiplies input torque several to dozens of times, making handwheel operation extremely easy even for large diameter, high pressure valves.
 
2. Self ocking Function: When the worm lead angle is smaller than the friction angle, the mechanism provides reverse self locking, securely holding any valve position without external brakes for enhanced safety.
 
3. Visual Position Indicator: A mechanical opening indicator is typically mounted on the gearbox top, clearly displaying the current valve opening percentage for convenient on site monitoring.
 
4. High Protection Class: Fully enclosed housing offers dust and water resistance (IP65 or higher), suitable for outdoor, humid, or dusty environments.
 
5. Electric Upgrade Ready: The worm gear drive can be retrofitted with a motor adapter without replacing the valve body, enabling quick automation for remote control.

Packaging & Shipping

Our key points to keep in mind when packaging valve products:

1. Protection Against Contamination
Valves must be sealed at all openings (flanges, threaded ends, or socket ends) with appropriate caps, plugs, or covers. This prevents dust, dirt, moisture, and foreign particles from entering the internal cavities and seating surfaces, which could compromise performance.
 
2. Corrosion Prevention
Apply a rust-preventive coating or volatile corrosion inhibitor (VCI) film to all machined and unpainted metal surfaces. Desiccant bags should be placed inside sealed plastic liners to control humidity, especially for long-term storage or ocean freight.
 
3. Cushioning and Shock Absorption
Use adequate padding (e.g., foam, bubble wrap, or corrugated cardboard inserts) to protect actuators, positioners, handwheels, and other protruding components. Fragile accessories like solenoid valves or limit switches require additional isolation from the main valve body.
 
4. Secure Fixation Inside the Container
The valve must be firmly blocked and braced within the outer packaging (wooden crate, corrugated box, or metal rack) using wooden chocks, metal brackets, or strapping bands. This prevents shifting, rolling, or impacting during handling and transit, which could damage threads, flanges, or stem seals.
 
5. Weight Distribution and Lifting Points
For heavy or large-diameter valves, ensure the packaging design evenly distributes weight and provides clear, reinforced lifting points (e.g., sling slots or fork-lift pockets). Mark the center of gravity on the outside to avoid tipping.
 
6. Clear and Durable Labeling
Attach weather-resistant labels showing:
Valve model, size, pressure class, and material grade
Purchase order number and batch/lot code
Handling instructions (e.g., "Do Not Drop," "This Side Up," "Use Spreader Bar")
Weight and center-of-gravity markings
 
7. Compliance with Export/Import Regulations
For international shipments, use Non solid wood material without fumigation wooden pallets/boxes. Include proper hazardous goods declarations if the valve contains residual testing fluids, lubricants, or nitrogen pre-charge.

More Catagory of Butterfly Valve

Concentirc Butterfly Valve

Triple Offset Butterfly Valve

Double Eccentric Butterfly Valve

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