Pneumatic Wafer Lug Butterfly Valve

Product Overview

The Pneumatic Wafer Lug Butterfly Valve features a slim, wafer-style body that is clamped between two pipeline flanges, while also incorporating integral lugs (projections) with bolt holes. This hybrid design allows the valve to be mounted and removed independently of the adjacent piping, significantly simplifying maintenance, inspection, and isolation procedures.

Powered by a reliable pneumatic actuator, this valve offers fast, efficient on/off operation or modulating control. The actuator is typically controlled by a solenoid valve and can be equipped with positioners for proportional flow regulation using 4-20mA signals.

Constructed from durable materials such as ductile iron or stainless steel, and featuring resilient seats (EPDM, NBR, PTFE), the Pneumatic Wafer Lug Butterfly Valve provides excellent sealing performance and corrosion resistance for a wide range of media, including water, air, oil, gas, and mild chemicals. Its versatility makes it a popular choice for numerous industrial and commercial applications.

Key Features & Benefits

Pneumatic Actuation

Offers fast, reliable, and cost-effective automated operation using compressed air, suitable for a wide range of industrial environments.

Hybrid Wafer-Lug Design

Combines the space-saving profile of a wafer valve with the maintenance-friendly isolation capability of a lug valve, eliminating the need to disassemble adjacent piping for valve removal.

Modulating Control Option

Can be equipped with a positioner for proportional flow control using 4-20mA signals, enabling precise flow regulation in automated systems.

Resilient Seating

Provides superior sealing performance with resilient materials (EPDM, NBR, PTFE), suitable for a wide range of media and temperatures.

Easy Maintenance

Lug connections allow the valve to be removed from the pipeline for inspection or replacement without disturbing upstream or downstream piping, reducing downtime and maintenance costs.

ISO 5752 & API 609 Compliance

Designed and manufactured to meet international standards, ensuring compatibility and reliability in global industrial applications.

Technical Specifications

Basic Parameters

Parameter	Specification Range
Nominal Diameter (DN/NPS)	DN50 ~ DN1200 (2" ~ 48")
Nominal Pressure (PN/Class)	PN10, PN16, PN25 Class 150, Class 300
Operating Temperature	-40°F ~ 392°F (-40°C ~ 200°C)
Applicable Media	Water, Air, Oil, Gas, Mild Chemicals, Slurries
Sealing Class	ISO 5208 Class IV or V

Material Specifications

Component	Material Options	Standards/Features
Valve Body	Ductile Iron, Carbon Steel, Stainless Steel	EN-GJS-400-15, ASTM A216 WCB, ASTM A351 CF8/CF8M
Disc	Ductile Iron, Stainless Steel, Ni-Resist	EN-GJS-400-15, AISI 304/316, Ni-Resist D2
Seat	EPDM, NBR, PTFE, PFA	Corrosion and Temperature Resistant, Abrasion Resistant
Shaft	Stainless Steel	AISI 304/316
Actuator	Pneumatic (Double-Acting or Spring-Return)	5-10 bar (70-145 psi) Air Supply, Positioner Option

Standards & Compliance

Design Standards: ISO 5752, API 609
Flange Standards: ISO 7005-1, ANSI B16.5 Class 150/300
Testing Standards: ISO 5208, API 598
Certifications: CE, ISO 9001

Working Principle

The Pneumatic Wafer Lug Butterfly Valve operates using a rotating disc controlled by a pneumatic actuator, with the added benefit of independent mounting via its lug design:

Pneumatic Actuation: The pneumatic actuator receives compressed air signals from a control system (e.g., solenoid valve) and rotates the valve shaft to open or close the disc.
Opening Process: Rotating the disc to a parallel position with the flow direction allows media to pass through the valve with minimal pressure drop.
Closing Process: Rotating the disc to a perpendicular position blocks the flow path, creating a tight seal against the resilient seat.
Modulating Control: When equipped with a positioner, the actuator adjusts the disc position based on an input signal (e.g., 4-20mA) to maintain a desired flow rate.
Lug Design Benefit: The integral lugs allow the valve to be bolted to the pipeline flanges using its own bolts. This means the valve can be removed for maintenance or replacement by simply unbolting it from the lugs, without the need to disconnect the entire pipeline section.

Application Areas

Water & Wastewater

Municipal water supply, wastewater treatment, and irrigation systems, where maintenance access is crucial.

HVAC & Building Services

Heating, ventilation, and air conditioning systems in commercial buildings, offering space-saving installation and easy servicing.

Oil & Gas

Midstream pipeline transportation and distribution systems, where isolation for pigging operations or maintenance is required.

General Industry

Chemical processing, food and beverage, pulp and paper, and power generation industries, providing reliable flow control with minimal downtime.

Installation & Maintenance

Installation Guidelines

Inspect the valve and actuator for damage before installation. Ensure the valve is in the closed position.
Clean the pipeline flanges and ensure they are flat and free of debris. Position the valve between the flanges, ensuring proper alignment of the lug holes with the flange bolt holes.
Use appropriate gaskets and insert the flange bolts through the valve lugs and into the pipeline flanges. Tighten the bolts evenly in a crisscross pattern to ensure a leak-free seal.
Connect the actuator to the air supply and control system according to the manufacturer's instructions. Test the actuator for proper operation before commissioning.
Conduct hydrostatic testing (1.5×PN) and leakage testing after installation to verify performance.

Maintenance Recommendations

Regularly inspect the seat for signs of wear or damage. Replace the seat if necessary to maintain sealing performance.
Clean the valve interior periodically to remove any buildup or debris that may affect operation.
Check the actuator air supply and connections for leaks or blockages. Replace any faulty components as needed.
Lubricate the actuator bearings and gearbox (if equipped) annually or as per manufacturer recommendations.
For maintenance or replacement, simply unbolt the valve from the pipeline flanges using the lug bolts. The adjacent piping remains intact, significantly reducing downtime.

Frequently Asked Questions (FAQ)

Q: What is the difference between a wafer, lug, and double-flange butterfly valve?

A: A wafer valve is clamped between flanges without its own bolts. A lug valve has lugs with bolt holes for independent mounting and easy removal. A double-flange valve has its own integral flanges, bolted directly to pipeline flanges, offering the most robust connection but at a higher cost and weight.

Q: Can the Pneumatic Wafer Lug Butterfly Valve be used for throttling applications?

A: Yes, when equipped with a positioner for 4-20mA control, this valve can be used for throttling applications. However, for precise flow control, consider a control valve with a suitable flow characteristic.

Q: What is the maximum operating pressure for a Pneumatic Wafer Lug Butterfly Valve?

A: The maximum operating pressure typically ranges from PN10 (1.0 MPa) to PN25 (2.5 MPa) or Class 150 (2.0 MPa) to Class 300 (5.0 MPa), depending on the valve size, material, and seat design. Consult the technical specifications for exact pressure ratings.

Q: Is the Pneumatic Wafer Lug Butterfly Valve suitable for vacuum applications?

A: Yes, this valve can be used for vacuum applications with appropriate seat materials (e.g., PTFE) and actuator selection. The lug design also facilitates easy installation and maintenance in vacuum systems. Consult with our engineering team to ensure proper configuration.

Need Custom Solutions?

Our engineering team can customize Pneumatic Wafer Lug Butterfly Valves to meet your specific pressure, temperature, and media requirements. Contact us today for a personalized quote.

Contact Our Technical Team