Choosing the right butterfly valve isn’t simply a matter of matching the valve size to the pipeline. The correct selection depends on the fluid, pressure, temperature, flow rate, operating frequency, connection type, seat material, body material, and actuator requirements.
A well-designed butterfly valve selection chart makes this process easier by organizing the most important selection criteria in one place. It can help engineers, purchasing teams, contractors, and maintenance professionals quickly compare valve options before making a final specification.
The wrong valve, on the other hand, can lead to leakage, excessive torque, corrosion, poor flow control, premature seat failure, or unexpected downtime.
This guide provides a practical selection framework for industrial butterfly valves, including valve construction, materials, pressure classes, seat options, actuation, and application requirements.
For projects requiring flanged connections, you can also explore our flanged valve product range.
Butterfly Valve Selection Chart at a Glance
The following chart provides a general starting point. Final selection should always be checked against the manufacturer’s technical data and the actual operating conditions.
| Selection Factor | Common Options | Main Consideration |
|---|---|---|
| Valve design | Concentric, double offset, triple offset | Service severity and sealing requirements |
| Body material | Cast iron, ductile iron, carbon steel, stainless steel | Pressure, corrosion, temperature |
| Disc material | Ductile iron, stainless steel, aluminum bronze, etc. | Fluid compatibility and corrosion |
| Seat material | EPDM, NBR, PTFE, FKM, metal | Fluid and temperature |
| Connection | Wafer, lug, flanged | Pipeline configuration |
| Pressure rating | PN10, PN16, Class 150, etc. | Operating pressure |
| Operation | Lever, gear, electric, pneumatic, hydraulic | Size and automation |
| Temperature | Low, ambient, high temperature | Seat and body compatibility |
| Service | Water, wastewater, chemical, oil, gas, etc. | Material compatibility |
| Function | Isolation or control | Required flow performance |
This table is a general selection guide, not a substitute for valve-specific engineering data.
1. Start With the Butterfly Valve Application
Before choosing materials or actuators, define what the valve needs to do.
Ask:
- What fluid will pass through the valve?
- What is the normal pressure?
- What is the maximum pressure?
- What is the minimum and maximum temperature?
- What is the normal flow rate?
- What is the maximum flow rate?
- How frequently will the valve operate?
- Is the valve for isolation or throttling?
- Is the fluid corrosive or abrasive?
- Is zero or bubble-tight shut-off required?
These questions establish the basic operating envelope.
A valve used for clean cooling water has very different requirements from a valve used for corrosive chemicals or high-temperature steam.
2. Select the Right Butterfly Valve Design
Butterfly valves can be divided into several major designs.
Concentric Butterfly Valve
The shaft and disc are arranged around the centerline of the valve.
These valves are commonly used for:
- Water
- HVAC
- Cooling systems
- Wastewater
- General industrial service
They are popular because they’re relatively simple, compact, and economical.
Double Offset Butterfly Valve
A double offset design moves the shaft away from the centerline.
This reduces rubbing between the disc and seat during operation.
Potential advantages include:
- Reduced seat wear
- Lower friction
- Improved durability
- Higher-performance sealing
Double offset valves can be considered for more demanding industrial applications.
Triple Offset Butterfly Valve
Triple offset designs add another geometric offset to the sealing arrangement.
The disc moves away from the seat in a way that minimizes sliding contact.
They’re commonly considered for demanding applications such as:
- High temperature
- High pressure
- Steam
- Critical isolation
- Metal-seated service
The correct design depends on the actual operating requirements.
3. Select the Correct Valve Material
Material selection is one of the most important parts of a butterfly valve specification.
Cast Iron
Cast iron butterfly valves are commonly used for general water and HVAC applications where the pressure, temperature, and corrosion environment are suitable.
Ductile Iron
Ductile iron generally provides higher mechanical strength than conventional cast iron and is widely used in industrial and water systems.
Carbon Steel
Carbon steel is commonly selected for applications requiring higher strength and broader industrial service capability.
Stainless Steel
Stainless steel is useful when corrosion resistance is important.
Different stainless grades have different corrosion resistance, so the exact grade should be selected according to the fluid and environment.
Aluminum Bronze
Aluminum bronze can be useful in selected marine and corrosive environments.
It is often considered for seawater-related applications, but the exact alloy and service conditions should be evaluated.
4. Choose the Correct Butterfly Valve Seat
The seat is critical to shut-off performance.
Common seat materials include:
| Seat Material | Typical Applications | Important Consideration |
|---|---|---|
| EPDM | Water, cooling water | Check compatibility with oils and temperature |
| NBR | Oil-related services | Check chemical and temperature limits |
| PTFE | Chemical service | Excellent chemical resistance; check mechanical limits |
| FKM | Selected chemical/hydrocarbon services | Verify exact chemical compatibility |
| Metal | High-temperature/severe service | Requires suitable valve design |
There isn’t one “best” seat material for every application.
The correct material depends on the actual:
- Fluid
- Temperature
- Pressure
- Concentration
- Operating frequency
5. Select the Correct Pressure Rating
Pressure rating must be evaluated together with temperature.
Common specifications may include:
- PN10
- PN16
- PN25
- Class 150
- Other application-specific ratings
Don’t assume that a valve’s nominal rating means it can operate at that pressure under every temperature condition.
Always check the manufacturer’s pressure-temperature rating.
Example
A pipeline operating at moderate pressure and ambient temperature may be suitable for a PN16 valve, while a high-temperature application may require a different pressure-temperature assessment.
The correct specification should be based on the maximum design pressure and temperature, not just normal operating conditions.
6. Select the Correct Valve Size
Valve size should be based on hydraulic requirements rather than pipe diameter alone.
Consider:
- Minimum flow
- Normal flow
- Maximum flow
- Pressure drop
- Valve Cv
- Fluid properties
- Required control range
An oversized butterfly valve can create poor control resolution.
An undersized valve can create:
- Excessive pressure drop
- High velocity
- Noise
- Vibration
- Increased wear
For control applications, valve sizing is especially important.
7. Choose the Correct Connection Type
Butterfly valves are available with different connection arrangements.
Wafer Butterfly Valve
Wafer valves are installed between pipeline flanges.
Advantages can include:
- Compact construction
- Low weight
- Simple installation
- Lower material cost
They’re widely used in many water and industrial systems.
Lug Butterfly Valve
Lug valves have threaded or tapped lugs that allow installation between flanges and can be useful where one side of the pipeline may need to be removed.
Flanged Butterfly Valve
Flanged butterfly valves have integral flanges and are often selected when a more conventional flanged connection is required.
They can be useful for:
- Industrial pipelines
- Large-diameter systems
- Higher mechanical requirements
- Specific piping standards
Connection selection should match the pipeline flange standard and project specification.
8. Select the Right Operating Method
Butterfly valves can be manually or automatically operated.
Lever Operated
Common for smaller valves and applications where frequent automation isn’t required.
Advantages:
- Simple
- Low cost
- Easy to operate
Gear Operated
A gearbox can reduce the manual operating force required for larger valves.
It’s often used when direct lever operation becomes impractical.
Electric Actuator
Suitable when the valve needs electrical automation.
Applications can include:
- Remote operation
- Automated process systems
- HVAC
- Water treatment
Pneumatic Actuator
Pneumatic actuators are common in industrial automation.
They can provide rapid operation and are useful where compressed air is available.
Hydraulic Actuator
Hydraulic actuation can be considered where very high operating forces are required or where hydraulic systems are already available.
9. Consider Temperature and Fluid Compatibility
Temperature should always be considered together with material selection.
For example:
- Low-temperature service can affect elastomer flexibility.
- High-temperature service can degrade conventional soft seats.
- Chemical exposure can change material performance.
- Thermal cycling can affect sealing components.
For high-temperature applications, metal-seated or offset butterfly valves may be more appropriate depending on the application.
Don’t select a seat material solely from a generic temperature chart. The actual fluid and pressure must also be considered.
10. Determine Whether the Valve Is for Isolation or Control
This is a major selection decision.
Isolation Service
The valve is primarily used to:
- Start or stop flow
- Isolate equipment
- Provide emergency shut-off
- Separate pipeline sections
A conventional resilient seated butterfly valve may be suitable for many applications.
Control Service
The valve is expected to regulate flow continuously.
In this situation, consider:
- Cv
- Flow characteristic
- Valve authority
- Pressure drop
- Operating range
- Noise
- Cavitation
- Actuator positioning accuracy
A valve designed for simple isolation shouldn’t automatically be treated as a precision control valve.
Butterfly Valve Selection Chart by Application
| Application | Common Valve Considerations |
|---|---|
| Drinking water | EPDM seat, approved materials, corrosion resistance |
| Cooling water | EPDM or suitable elastomer, corrosion resistance |
| Wastewater | Abrasion, solids, corrosion, seat durability |
| Desalination | Seawater corrosion resistance |
| Oil service | NBR/FKM or other compatible seat |
| Chemical service | PTFE or chemically compatible material |
| High-temperature service | Metal seat/offset design where appropriate |
| Steam | High-temperature design and pressure-temperature rating |
| HVAC | Compact concentric design, appropriate seat |
| General industrial | Material and pressure based on process conditions |
These are starting points, not universal specifications.
Butterfly Valve Selection Chart by Material
| Valve Material | General Strength | Corrosion Resistance | Typical Use |
|---|---|---|---|
| Cast iron | Moderate | Moderate in suitable environments | Water, HVAC |
| Ductile iron | Higher | Moderate | Water, industrial |
| Carbon steel | High | Requires suitable protection | Industrial service |
| Stainless steel | High | High in suitable environments | Corrosive/clean service |
| Aluminum bronze | High | Good in selected marine environments | Seawater/marine |
Actual performance depends on the grade, coating, fluid, temperature, and pressure.
Butterfly Valve Selection Chart by Seat Material
| Seat | Typical Service | Key Advantage | Watch Out For |
|---|---|---|---|
| EPDM | Water | Good water compatibility | Many oil services |
| NBR | Oil-related service | Oil resistance | Some chemicals/high temperatures |
| PTFE | Chemical service | Broad chemical resistance | Mechanical/temperature limitations |
| FKM | Hydrocarbons/chemicals | Good chemical and temperature performance in suitable service | Exact fluid compatibility |
| Metal | Severe/high-temperature | High-temperature capability | Higher complexity |
Always verify the specific compound and manufacturer’s compatibility information.
Butterfly Valve Selection Chart for Actuation
| Valve Size / Requirement | Typical Operation | Application |
|---|---|---|
| Small, infrequent operation | Lever | Manual isolation |
| Larger manual valve | Gear | Manual isolation |
| Remote automatic operation | Electric | Automated process |
| Fast automatic operation | Pneumatic | Industrial automation |
| Very high operating force | Hydraulic | Specialized heavy-duty service |
The valve’s actual torque requirements should be used for actuator sizing.
How to Use a Butterfly Valve Selection Chart
A good selection process can be simplified into these steps:
Step 1: Identify the Medium
Water? Oil? Gas? Chemical? Steam? Slurry?
Step 2: Determine Pressure and Temperature
Use the maximum design conditions, not just normal operating values.
Step 3: Determine Flow Requirements
Establish minimum, normal, and maximum flow.
Step 4: Select the Valve Design
Choose concentric, double offset, triple offset, or another appropriate design.
Step 5: Select Materials
Match body, disc, shaft, and seat materials to the process.
Step 6: Select Connection
Choose wafer, lug, or flanged construction according to the piping design.
Step 7: Select Actuation
Determine whether the valve should use a lever, gearbox, electric actuator, pneumatic actuator, or hydraulic actuator.
Step 8: Check Cv and Pressure Drop
Confirm that the selected valve meets hydraulic requirements.
Step 9: Check Leakage Requirements
Determine the required shut-off performance.
Step 10: Confirm the Complete Specification
Verify every selection against the manufacturer’s datasheet before ordering.
Common Butterfly Valve Selection Mistakes
Choosing by Size Alone
A DN200 pipeline doesn’t automatically require a DN200 valve with no further analysis.
Ignoring Temperature
A seat material suitable at ambient temperature may not perform properly at elevated temperature.
Ignoring Fluid Compatibility
Chemical compatibility should always be checked.
Using the Wrong Pressure Rating
The maximum pressure and temperature should be considered together.
Undersizing the Actuator
The actuator needs enough torque for the actual operating conditions.
Oversizing the Actuator
Excessive actuator torque can create unnecessary mechanical loading.
Ignoring Installation Conditions
Pipe alignment and disc clearance can affect valve performance.
Using an Isolation Valve for Demanding Control
Continuous throttling may require a valve specifically designed for control duty.
Butterfly Valve Selection Specification Checklist
Before sending a valve inquiry to a manufacturer or supplier, prepare the following information:
- Valve type: Butterfly
- Nominal size: DN/ANSI size
- Connection: Wafer/lug/flanged
- Pressure rating: PN/Class
- Body material: Required grade
- Disc material: Required grade
- Seat material: EPDM/NBR/PTFE/FKM/metal
- Fluid: Actual process medium
- Temperature: Minimum/normal/maximum
- Pressure: Minimum/normal/maximum
- Flow rate: Minimum/normal/maximum
- Operation: Manual/electric/pneumatic/hydraulic
- Function: Isolation/control
- Leakage requirement: Applicable specification
- Applicable standards: Project requirements
- Special requirements: Coating, approvals, testing, etc.
Providing this information upfront makes technical quotation and valve selection much more efficient.
Frequently Asked Questions
What is a butterfly valve selection chart?
A butterfly valve selection chart is a practical reference that compares valve designs, materials, seat options, pressure ratings, connections, actuation methods, and applications to help users select an appropriate valve.
How do I choose the right butterfly valve?
Start with the fluid, pressure, temperature, flow rate, and operating requirements. Then select the valve design, body and disc materials, seat material, connection type, pressure rating, and actuator.
Should butterfly valve size match the pipe size?
Not always. The valve should be hydraulically sized according to flow rate, pressure drop, Cv, and control requirements. Matching pipe diameter without checking these factors can result in poor performance.
Which butterfly valve seat material is best for water?
EPDM is commonly used for many water applications, subject to the specific water chemistry, temperature, and required approvals.
Which butterfly valve is best for high-temperature applications?
The appropriate choice depends on temperature, pressure, fluid, and sealing requirements. Metal-seated and offset butterfly valves may be suitable for certain high-temperature services.
What is the difference between wafer and flanged butterfly valves?
A wafer valve is typically installed between pipeline flanges, while a flanged butterfly valve has integral flanges that connect directly to the pipeline flanges. The choice depends on piping requirements and project specifications.
How do I select a butterfly valve actuator?
Determine the valve’s required operating torque under the worst expected conditions, then select an actuator that provides adequate torque and suitable control characteristics. The manufacturer’s torque data should be used whenever possible.
Can butterfly valves be used for flow control?
Yes, but suitability depends on the valve design and application. Basic butterfly valves can provide regulation, while demanding control applications may require purpose-designed control butterfly valves.
What information should I provide when requesting a butterfly valve quotation?
Provide valve size, connection, pressure rating, fluid, temperature, pressure, flow rate, materials, seat material, operation method, leakage requirements, and applicable standards.
Conclusion
A reliable butterfly valve selection chart is useful because it brings the major selection factors together, but choosing the correct valve still requires an understanding of the actual process.
The most important factors are fluid, pressure, temperature, flow rate, valve design, materials, seat, connection, pressure rating, and actuation. Once these requirements are defined, the available butterfly valve options become much easier to narrow down.
For general water and HVAC applications, a concentric resilient seated butterfly valve may be a practical choice. More demanding applications may require double offset, triple offset, metal-seated, corrosion-resistant, or specially actuated designs.
Most importantly, don’t select a butterfly valve based on size or price alone. A valve that matches the process conditions correctly can provide better sealing, smoother operation, longer service life, and lower lifecycle cost.
A properly completed selection specification also gives manufacturers and suppliers the information they need to recommend the right configuration and provide an accurate quotation.