Butterfly valves follow different standards based on where they’re used. You can see API 609 in petroleum service, ASME B16.34 in power and process plants, AWWA C504 in water systems, and ISO 5752 or EN 593 in European projects. It means each industry leans on the standard that matches its pressure class, materials, and regional rules.
Why Butterfly Valve Standards Matter
Standards set the butterfly valve design and the tests every valve has to pass. You can’t guarantee a safe system without them. Valves wouldn’t align, parts wouldn’t match, and the whole pipeline would face unnecessary risk.
The butterfly valve specification standard you follow decides flange fit, pressure rating, and material grade. It means engineers need to match each butterfly valve standard to the system’s pressure, flow, and media so everything runs the way it should.
This artical would help you understanding more about Butterfly Valve Testing:
Butterfly Valve Standard Sizes and Dimensions
The butterfly valve standard sizes vary by application and governing standard. API standards cover valves from 2 inches through 72 inches, while AWWA extends to 120 inches for large water transmission lines.
Because each butterfly valve dimensions standard uses its own face-to-face rules, the same valve size can differ across standards. The table below shows how common sizes compare:
| Valve Size | API 609 (mm) | ASME B16.10 (mm) | EN 558 Series 14 (mm) |
| DN50 (2″) | 43 | 108 | 43 |
| DN100 (4″) | 56 | 165 | 108 |
| DN150 (6″) | 56 | 216 | 108 |
| DN300 (12″) | 76 | 292 | 127 |
A DN100 valve measures 108mm under EN 558 but 165mm under ASME B16.10. Always check that the dimensional standard aligns with your piping specification to avoid installation issues.
Connection type also changes dimensions:
- Wafer-type valves have shorter face-to-face lengths than flanged versions
- Lug-type valves allow dead-end service and can simplify maintenance
- High-performance valves may require longer dimensions for disc clearance
What Is the ASME Standard for Butterfly Valves?
ASME B16.34 sets the pressure-temperature ratings used in process plants and power applications. You can rely on it to show how pressure limits change as temperature rises. A Class 150 butterfly valve handles 285 PSI at 100°F, but that number drops to 230 PSI at 400°F. It means the valve’s strength shifts with heat, and the standard tells you exactly how much.
ASME B16.10 defines the butterfly valve dimensions standard for face-to-face and end-to-end lengths. These measurements keep valves interchangeable, so you can place any manufacturer’s valve between the same flanges without modification. ASME standards work alongside ANSI B16.5, giving you a full set of rules for system compatibility.
| ASME Class | Max Pressure at 100°F | Max Pressure at 400°F | Typical Applications |
| Class 150 | 285 psi | 230 psi | General process systems |
| Class 300 | 740 psi | 600 psi | High-pressure applications |
| Class 600 | 1480 psi | 1200 psi | Critical pressure services |
For more Butterfly Valve Pressure Rating Information, you can also see our another topic:
[Butterfly Valve Pressure Rating Standards: PN16 / PN25 / PN40 / Class 150]
What Is the AWWA Standard for Butterfly Valves?
AWWA C504 sets the requirements for butterfly valves used in water and wastewater systems. You can see this standard applied in municipal treatment plants, distribution lines, and sewage networks. It means the design rules focus on clean water compatibility and long-term performance in buried or submerged conditions.
The standard highlights corrosion resistance and material durability. That can include resistance to chlorinated water and common treatment chemicals, so the valve doesn’t degrade over time.
AWWA C504 defines the butterfly valve standard sizes used across water systems:
- Sizes range from 3 inches to 120 inches
- Face-to-face dimensions follow tables different from API or ASME
- Pressure ratings use PN values like PN10, PN16, and PN25
This approach reflects European influence and global water industry practice. It also means AWWA valves do not interchange with petroleum service valves because the dimensional rules are different.
ISO and EN Standards for Butterfly Valves
ISO 5752 (Series 14) sets face-to-face dimensions for European installations. You can rely on this butterfly valve dimensions standard to keep valves from different manufacturers compatible in the same piping layout.
EN 593 defines metal butterfly valves for general service. It covers design, materials, and testing requirements that follow the same intent as API 609, but everything is set in metric terms. EN 12266 outlines the testing process, including shell tests, seat tests, and operational checks. It means the standard butterfly valve in European systems usually follows EN 558-1 Series 14 for face-to-face length.
ISO 5211 defines the interface between the valve and the actuator. You can mount pneumatic or electric actuators from different brands without custom brackets. That level of interchangeability keeps maintenance simple and supports automation upgrades across facilities.
Material and Testing Standards
Testing requirements vary by standard. API 609 requires shell testing at 1.5x working pressure and seat testing at 1.1x working pressure. AWWA C504 includes similar tests plus operational torque measurements to verify actuator sizing.
Fire-safe butterfly valves must meet API 607 or ISO 10497, demonstrating they maintain sealing integrity after fire exposure. These requirements apply primarily to hydrocarbon service valves.
Material specifications reference ASTM standards for body, disc, and seal components:
Body Materials:
- ASTM A126: Cast iron for low-pressure water service
- ASTM A536: Ductile iron for general industrial applications
- ASTM A351: Cast stainless steel for corrosive environments
Seal Materials:
- EPDM: Water and steam service, -40°C to 150°C
- NBR: Petroleum products, -30°C to 100°C
- PTFE: Chemical resistance, -200°C to 200°C
Selecting the Right Standard for Your Application
Different butterfly valve applications require different standards based on the industry:
- Oil & Gas: API 609 with ASME pressure class ratings for hydrocarbon service
- Water Systems: AWWA C504 for potable water and buried installations
- Chemical Processing: EN 593 or ISO 5752 based on geographic location
- Power Generation: ASME B16.34 for high-pressure steam and boiler feedwater
At CTGV, we’ve been manufacturing butterfly valves for over 16 years. Our butterfly valves carry API 609, EN 593, and ISO 5752 certifications, backed by API6D, ISO9001, and fire-safe API607 compliance. You can work with our engineering team to match valve specifications to your project’s exact standard requirements through our collaborative R&D approach.
Check CTGV Buttfly Valve Collection for Certain Industry
Key Takeaways on Butterfly Valve Standards
The standards for butterfly valves vary across different applications and industries:
- API 609 dominates oil, gas, and petrochemical applications with three service categories
- ASME B16.34 defines pressure-temperature ratings for North American projects
- AWWA C504 addresses water and wastewater systems up to 120 inches
- ISO 5752 and EN 593 serve European and international markets with metric dimensions
- Face-to-face dimensions vary significantly between API, ASME, and EN specifications
Contact our team for valve specification support tailored to your project’s requirements.
