Butterfly Valves: The Complete Guide to Types, Applications, Standards & Selection

Why Butterfly Valves Matter in Modern Flow Control

In the world of industrial flow control, reliability, efficiency, and space-saving design are critical. That’s where Butterfly Valves come into play. Known for their compact size, quick operation, and versatility across a wide range of industries, butterfly valves have become a go-to solution for regulating and isolating flow in pipelines.

Butterfly valves are one of the most widely used industrial valves for isolating or regulating flow in pipelines. Whether you are working on a municipal water project in the UK, a petrochemical plant in the Middle East, or a HVAC installation in Canada, selecting the right butterfly valve can directly impact the performance and lifespan of your entire system.

This comprehensive guide is designed to help engineers, procurement professionals, and project decision-makers understand:

• The different types of butterfly valves
• Their applications and advantages
• Common standards and specifications
• How to make the right selection based on your specific needs

Let’s dive in.

What Is a Butterfly Valve?

A butterfly valve is a quarter-turn rotational motion valve used to start, stop, and regulate flow. The main feature is a disc mounted on a rotating shaft, which opens or closes the flow path with a 90° turn.

When fully open, the disc is parallel to the flow and offers minimal resistance. When closed, it seals against a seat to stop flow. Thanks to their lightweight construction and fast actuation, butterfly valves are ideal for large-diameter pipelines and systems requiring quick shut-off.

Common Uses:

• On-off or throttling control
• Applications where tight shut-off is not critical
• Systems requiring fast actuation

Butterfly valves are favored for their ease of installation and suitability.

Butterfly Valve Working Principle

The working principle of a butterfly valve is based on the rotation of a disc inside the valve body. When the disc is parallel to the flow, the valve is open. When turned 90 degrees, it becomes perpendicular, blocking flow.

Key Components:

• Body: Houses the internal components; available in wafer, lug, or flanged types.
• Disc: The flow control element that rotates to open or close the valve.
• Seat: Provides sealing; can be soft-seated (EPDM, PTFE) or metal-seated.
• Stem: Connects the actuator or handle to the disc.
• Actuator: Can be manual, pneumatic or electric.

Butterfly valves offer minimal pressure drop and are ideal for quick opening and closing operations.

Types of Butterfly Valves

Butterfly valves come in several configurations to meet diverse operational needs. Each type offers different performance characteristics, installation methods, and suitability for specific applications.

Choosing the correct type of butterfly valve depends on your application, pressure rating and sealing needs. Here’s a breakdown of the main types:

1. Wafer Type Butterfly Valve

• Design: Clamped between two flanges using bolts
• Use Case: Ideal for HVAC systems, compressed air, and low-pressure water pipelines
• Benefits: Cost-effective, compact, lightweight
• Limitation: Not suitable for high-pressure applications

2. Lug Type Butterfly Valve

• Design: Threaded inserts allow the valve to be bolted to the pipeline
• Use Case: Common in dead-end service and modular pipeline construction
• Benefits: Can isolate one side of the piping system
• Note: Slightly heavier and more expensive than wafer type

3. Double Offset (High-Performance) Butterfly Valve

• Design: The shaft is offset from both the centerline of the disc and the pipe
• Use Case: Suited for chemical plants, oil refineries, and power generation
• Benefits: Reduced seat wear, excellent sealing, higher pressure ratings
• Standard Ratings: Often rated up to PN 25 / ANSI 300

4. Triple Offset Butterfly Valve

• Design: Adds a third offset, making the disc completely non-rubbing
• Use Case: Perfect for steam lines, high-temperature service, and zero-leakage applications
• Benefits: Metal-to-metal seal, fire-safe design, longer lifespan under extreme conditions

5. PTFE / Lined Butterfly Valve

• Design: Lined with PTFE, PFA, or other corrosion-resistant polymers
• Use Case: Ideal for aggressive chemicals, acids, and alkalies in chemical or pharmaceutical plants
• Benefits: Superior corrosion resistance and purity in the medium

6. Flanged End Type

• Design: Bolt holes for direct connection to pipe flanges
• Use Case: Suitable for larger valves
• Benefits: Easier installation and maintenance

7. High-Performance Butterfly Valve

• Design: Engineered for high pressure and temperature
• Use Case: Often used in oil & gas and power generation
• Benefits: Enhanced durability, sealing performance, and reliability under extreme conditions

Key Applications of Butterfly Valves by Industry

Butterfly valves are used in almost every flow-based industry. Here are some typical applications with examples:

International Standards for Butterfly Valves

For global compliance, butterfly valves are manufactured to several international standards, depending on region and application:

DIN EN 593 (Europe)

• Specifies dimensions, design, and testing for metallic butterfly valves
• Widely used in Germany, EU, and Eastern Europe

API 609 (USA, Middle East)

• Standard for lug and wafer type valves, with requirements for pressure classes, fire safety, and metal-seated designs
• Popular in oil & gas and petrochemical projects

BS 5155 (UK)

• British Standard for industrial butterfly valves
• Relevant for UK water authorities and EPC projects

AWWA C504 (USA/Canada)

• For large-diameter valves used in municipal water systems

JIS B2032 (Japan/Asia)

• Japanese Industrial Standard for butterfly valve design and materials

Make sure the valve you’re sourcing complies with your project specification, especially in regulated industries like oil & gas or pharmaceuticals.

How to Select the Right Butterfly Valve?

Key Considerations

Selecting the correct butterfly valve is crucial for ensuring long-term performance, operational safety, and cost-efficiency in industrial piping systems. Below are the key technical and procurement factors engineers and buyers must evaluate:

1. Operating Pressure & Temperature

• Ensure the butterfly valve’s pressure rating (PN 10/16/25 or ANSI Class 150/300) and temperature limits align with your system design.
• Example: In a high-temperature steam line (e.g., 450°C in a thermal power plant), a metal-seated triple offset butterfly valve would be required, rather than an elastomer-seated type.

2. Media Compatibility

• Consider the nature of the fluid or gas: Is it abrasive, corrosive, toxic, or viscous?
• Use PTFE-lined butterfly valves or high alloy grades for aggressive chemicals.
• Example: Sulfuric acid transfer lines demand non-reactive materials like PTFE lining or Alloy 20 to prevent corrosion and failure.

3. Material of Construction

• Material selection must be based on fluid type, temperature, and industry standards:
o Body: Cast Iron, Ductile Iron, Carbon Steel (ASTM A216 WCB), Stainless Steel (CF8M/CF8), Bronze, or Aluminum Bronze
o Disc: SS 316/304, Nickel-Aluminum Bronze (NAB), Duplex Stainless Steel, or PTFE-coated discs
o Seat: EPDM, NBR, Viton, PTFE, or Metal seated (for high-temp)
o Stem/Shaft: SS 410, SS 316, Monel, or Inconel

• Example: For seawater desalination plants, Nickel-Aluminum Bronze or Duplex Stainless Steel is recommended to resist chloride-induced corrosion.

4. End Connection Type

• Choose based on pipeline layout and maintenance needs:
o Wafer type: Fits between flanges with through-bolts — ideal for compact systems.
o Lug type: Allows one-side disassembly — used for dead-end service.
o Flanged type: Offers easy installation and better alignment — preferred in heavy-duty industrial pipelines.
•  Match with international standards like EN 1092-1, ASME B16.5, or BS 4504 depending on your region.

5. Actuation Method

• Select actuation based on automation needs and frequency of operation:
o Manual (Lever or Gear): Suitable for low-frequency use or small sizes.
o Pneumatic Actuator: For fast, fail-safe operation in automated systems.
o Electric Actuator: Offers precise flow control and integration with SCADA or BMS in HVAC, water, or energy sectors.
o Hydraulic Actuator: Needed for high-torque applications such as in hydro plants or large dam gates.

6. Installation Space

• Butterfly valves are ideal where space and weight are critical:
o Their short face-to-face dimensions, especially per EN 558 or API 609, make them suitable for skid packages, ship engine rooms, or compact process lines.
o Compared to gate or globe valves, they offer lighter weight, lower cost, and easier installation.

Practical Example: HVAC Project in Dubai

A commercial high-rise in Dubai required a reliable solution for chilled water isolation and zone control within limited shaft space. Engineers selected DN 200 Wafer Type Butterfly Valveswith gearbox operation and EPDM seat, ensuring low maintenance and efficient shutoff performance in the harsh desert climate.

Maintenance & Lifespan: Why Quality Matters

A well-selected butterfly valve with proper materials, actuation and standard compliance can last 10–15 years or more with minimal maintenance. However, in corrosive or high-cycling systems, metal seat valves or lined options with automated diagnostics can extend service life significantly.

Conclusion: Reliable Flow Starts with the Right Valve

Butterfly valves offer a powerful combination of cost-efficiency, lightweight construction, and versatile performance across industries. Whether you’re handling water, steam, chemicals or air, choosing the right type of butterfly valve ensures long-term system integrity, safety, and ease of maintenance.

Let’s Talk Valves — We’re Here to Help

At C-Way Engineering we specialize in manufacturing and supplying a wide range of industrial butterfly valves — from wafer and lug types to triple offset and PTFE-lined valves — built to international standards including DIN EN 593, API 609, and AWWA C504.

We serve clients across the USA, Canada, UK, EU, UAE, Middle East, Australia and Africa, with reliable delivery timelines and full technical support.

🔹 CE Certified | ISO 9001:2015 | Global Export Ready
🔹 Available Sizes: DN 40 to DN 1200 | Pressure Ratings: PN 6 to PN 40
🔹 Custom Material Options: SS316, WCB, Alloy 20, PTFE Lining, etc.

👉 Get in touch today for a quote, datasheet, or expert recommendation.
📩 sales@cwayexports.com | 📱 +91 93911 16127