Wafer Butterfly Valve: Working Principle, Applications(2025 Update)

Wafer butterfly valves are widely used in industrial applications due to their compact design, cost-effectiveness, and reliable performance in controlling fluid flow. As a key component in pipeline systems, wafer butterfly valves are essential for industries such as water treatment, HVAC, chemical processing, and oil & gas. This comprehensive guide will explain the working principle, key features, applications, and how to choose the right wafer butterfly valve for your industrial needs.

What is a Wafer Butterfly Valve?

A wafer butterfly valve is a quarter-turn valve that uses a circular disc to regulate fluid flow. The valve is designed to fit between two pipeline flanges, with the disc rotating around a central axis to open or close the flow path. The wafer design is one of the most common types of butterfly valves due to its lightweight construction, ease of installation, and cost-effectiveness.

EN593 Wafer Style Butterfly Valve With PINS

Parts of a Wafer Butterfly Valve

A wafer butterfly valve consists of several key components that work together to regulate fluid flow:

• Body: The main structure of the valve, typically made from stainless steel, cast iron, or ductile iron. The material selection depends on the application requirements, such as corrosion resistance, pressure rating, and operating temperature.

• Disc (Butterfly Plate): A circular component that rotates within the valve body to control fluid flow. Discs can be concentric or eccentric, with high-performance versions using double or triple offset designs to minimize friction and wear.

• Seat (Lining): A sealing element, typically made from elastomers such as EPDM, PTFE, or NBR. Advanced seat materials like Viton are used for aggressive chemicals, while metal seats are used for high-temperature applications.

• Stem (Shaft): The rod that connects the actuator or lever to the disc, transmitting the rotational motion. Stems are often made from stainless steel or other high-strength alloys with anti-corrosion coatings.

• Actuator/Handle: The manual lever, pneumatic actuator, or electric actuator used to control the valve's operation. Automated actuators are commonly used in industrial applications to ensure consistent performance and remote control.

• Bushings & Bearings: Support components that reduce friction and provide smooth rotation of the stem, often made from self-lubricating materials like PTFE or bronze.

The working principle of a wafer butterfly valve is based on the rotation of the disc inside the valve body. When the actuator or handle rotates the stem, the disc pivots around its axis, allowing or restricting the fluid flow.

• Fully Open Position: The disc aligns parallel to the pipeline, allowing maximum fluid flow with minimal pressure drop. This position is ideal for applications requiring maximum throughput.

• Partially Open Position: The disc is partially rotated, controlling the flow rate based on the degree of opening. This throttling capability makes wafer butterfly valves suitable for flow regulation applications.

• Fully Closed Position: The disc is perpendicular to the pipeline, creating a tight seal that prevents fluid flow. In bi-directional valves, the seat design ensures zero leakage in both flow directions.

Modern wafer butterfly valves may include triple offset disc designs, where the shaft is offset from both the centerline of the bore and the centerline of the seat. This minimizes seat contact during operation, reducing wear and extending service life.

Key Features of Wafer Butterfly Valves

• Compact and Lightweight Design

• Cost-Effective Solution

• Quick Quarter-Turn Operation

• Bubble-Tight Shutoff

• Suitable for On/Off and Throttling Applications

• Available in Various Materials (Stainless Steel, Cast Iron, PVC)

• Compliance with API 609 and ISO 9001 Standards

• Pressure Rating: ANSI 150-300

• Optional Actuation: Pneumatic or Electric

Bafaw wafer butterfly valves 100% Dimensional Inspection with CMM Report

Wafer Butterfly Valve vs Lug Butterfly Valve

Pros:

• Compact and lightweight design

• Cost-effective compared to gate and ball valves

• Easy installation between flanges without the need for additional gaskets

• Quick quarter-turn operation for fast shut-off

• Suitable for both liquid and gas applications

• Low pressure drop in fully open position

• Bi-directional sealing with minimal maintenance

Cons:

• Limited pressure ratings compared to lug or double-flanged butterfly valves

• Not ideal for high-temperature or high-pressure applications without special modifications

• Potential for wear and leakage in abrasive or slurry applications

• Disc may cause flow turbulence in partially open positions

• Lower sealing performance compared to ball or globe valves in high-pressure applications

Source：Google

Bafaw specializes in the custom production of industrial valves,is a professional manufacturer of industrial butterfly valves， including wafer butterfly valves, tailored to the unique needs of various industries. With over 10 years of experience in precision casting, forging, and machining, Bafaw delivers high-performance wafer butterfly valves with:

• Customizable materials for body, disc, and seat to match application requirements

• Compliance with international standards such as API 609, ISO 5211, and DIN 3354

• High-quality sealing solutions for both soft-seated and metal-seated applications

• Corrosion-resistant coatings such as epoxy and PTFE for harsh environments

• Advanced CNC machining processes ensuring tight tolerances and consistent performance

• Comprehensive pressure testing, including hydrostatic and pneumatic tests

Bafaw's engineering team works closely with clients to provide technical solutions that enhance operational efficiency and reliability, offering full documentation and traceability for each valve.

Conclusion

Wafer butterfly valves play a critical role in industrial flow control systems, offering cost-effective and efficient fluid regulation. While they may not be suitable for high-pressure or abrasive applications, their compact design, bi-directional sealing, and ease of installation make them a preferred choice in many industries. Bafaw's custom valve production capabilities ensure that clients receive reliable, high-performance wafer butterfly valves designed to meet specific operational requirements.

FAQ

1. What is the difference between wafer and lug butterfly valves?

Wafer butterfly valves are installed between flanges without bolt holes, while lug butterfly valves have threaded inserts allowing independent flange connections, making them suitable for end-of-line service.

2. Can wafer butterfly valves be used for throttling applications?

Yes, wafer butterfly valves can be used for throttling applications, especially in HVAC and water systems, but they may cause turbulence and are typically not recommended for precision flow control in high-pressure systems.

3. What is the pressure rating of a wafer butterfly valve?

Standard wafer butterfly valves typically have pressure ratings ranging from PN10 to PN16 or ANSI Class 150, but high-performance versions can be designed for up to ANSI Class 300.

4. How to choose the right seat material for a wafer butterfly valve?

The choice of seat material depends on the fluid type, temperature, and pressure. EPDM is commonly used for water applications, PTFE for chemical applications, and Viton for aggressive media and high temperatures.

5. What maintenance is required for wafer butterfly valves?

Regular inspections, lubrication of moving parts, and replacement of worn-out seals or seats are essential for ensuring long-term performance. Metal-seated versions may require additional cleaning and surface treatments.

This article is written by Bafaw Industrial Engineers with over 10+ years of experience in precision manufacturing, specializing in Wafer Butterfly Valves, Triple Offset Butterfly Valves, and Custom Metal Sealing Solutions.