NEWS
08
2026
-
05
Butterfly Valve Selection Guide: Types, Applications & Standards
Understanding Butterfly Valves
The butterfly valve is one of the most versatile quarter-turn valves in industrial
applications. Named for its disc-shaped closure element that rotates like
butterfly wings, it offers excellent flow control with minimal pressure drop when
fully open.
Main Types of Butterfly Valves
1. Concentric (Resilient Seated) Butterfly Valve
Design: Stem centered in disc, disc centered in body
Sealing: Rubber or elastomer liner provides bubble-tight shutoff
Pressure Rating: Typically up to Class 150 (PN16/PN25)
Best For: Water, HVAC, general industrial applications
Advantages: Lowest cost, excellent sealing, low torque
2. Double Eccentric (High Performance) Butterfly Valve
Design: Stem offset from disc center AND disc offset from pipe center
Sealing: PTFE or metal seat, cam action reduces seat wear
Pressure Rating: Up to Class 600 (PN100)
Best For: Chemical, petrochemical, steam applications
Advantages: Higher pressure/temperature capability, longer service life
3. Triple Offset Butterfly Valve
Design: Three offsets eliminate all rubbing contact during operation
Sealing: Metal-to-metal seat, torque-seated designPressure Rating: Class 150 to Class 2500 (full pressure range)
Best For: Critical isolation, high temperature, cryogenic services
Advantages: Zero leakage (Class VI), fire-safe, bidirectional tight shutoff
Key Selection Criteria
Common Application Mistakes
1. Incorrect Pressure-Temperature Selection
Many users select concentric valves for steam service or high-pressure
applications. For steam above 10 bar or temperatures above 120°C, double
eccentric or triple offset valves are required.
2. Cavitation Misdiagnosis
Butterfly valves are not designed for severe cavitation service. If cavitation
occurs: - Consider installing downstream orifice plates - Switch to rotary control
valves designed for cavitation - Add anti-cavitation trim if available
3. Actuator Sizing Errors
Butterfly valve torque characteristics: - Opening: Peak torque at ~75° open
(not fully closed) - Closing: Higher torque against flow direction - Dynamic
torque: Increases with flow velocity
Always specify maximum differential pressure and flow direction when sizing
actuators.
Standards & Specifications
Design Standards
API 609: Butterfly valves for general/refined petroleum
ASME B16.34: Pressure-temperature ratings
MSS SP-67: Butterfly valves
ISO 5752: Face-to-face dimensions
Testing Standards
API 598: Valve inspection and testing
ISO 5208: Industrial valve pressure testing
API 6D (for pipeline): Pipeline valves
Fire Safety
API 607: Fire test for soft-seated quarter-turn valves
ISO 10497: Fire type-testing requirements
Installation Best Practices
1. Orientation: Install with stem horizontal or tilted upward (not inverted)2. Flow Direction: Check arrow marking; some designs are unidirectional
3. Pipe Support: Support piping independently; do not use valve as pipe
support
4. Flange Gaskets: Use full-face gaskets for wafer-style valves
5. Clearance: Ensure sufficient clearance for disc rotation (disc extends
beyond face)
Summary
Key Takeaway: Butterfly valve selection is about matching the valve type to
service conditions. Concentric for general low-pressure service, double
eccentric for demanding chemical/steam applications, triple offset for critical
isolation where metal seats and zero leakage are required.
上一个
上一个
2025-02-27
请求报价
请填写此表格，我们将在下一个工作日联系您。