ANSI vs DIN vs GOST Flange Standards: International Comparison Guide for Global Projects
Navigating International Flange Standards
Global engineering projects often require understanding multiple pipe flange standards. This guide compares ANSI flange, DIN flange, and GOST flange specifications to help engineers select the right components for international applications.
ANSI/ASME Flange Standards
ANSI flange standards, now maintained by ASME, are the most widely used specifications in North America and many international projects.
Key ANSI Standards:
- ASME B16.5: Pipe flanges and flanged fittings NPS ½” through 24″
- ASME B16.47 Series A & B: Large diameter flanges NPS 26″ through 60″
- ASME B16.1: Cast iron pipe flanges
- ASME B16.24: Copper alloy pipe flanges
ANSI Pressure Classes:
- Class 150, 300, 400, 600, 900, 1500, 2500
- Pressure-temperature ratings per ASME B16.5
- Standard bolt patterns and dimensions
Common ANSI Flange Types:
- Weld Neck, Slip-On, Socket Weld
- Lap Joint, Threaded, Blind
- Reducing, Expander, Orifice flanges
DIN Flange Standards (German)
DIN flange specifications are prevalent in European and international projects, particularly in chemical and process industries.
Key DIN Standards:
- DIN 2501: Flanges and bolted connections
- DIN 2527: Bridas ciegas
- DIN 2573: Loose plate flanges
- DIN 2630-2638: Weld neck flanges (PN 2.5 to PN 40)
DIN Pressure Ratings (PN):
- PN 2.5, 6, 10, 16, 25, 40, 63, 100
- PN = Nominal Pressure in bar
- Different from ANSI class designations
DIN vs ANSI Key Differences:
- Bolt hole patterns differ significantly
- Flange thickness varies
- Gasket dimensions not interchangeable
- Pressure-temperature ratings differ
GOST Flange Standards (Russian)
GOST flange standards are required for projects in Russia, CIS countries, and regions influenced by Soviet engineering practices.
Key GOST Standards:
- GOST 12815-80: Flange types and main dimensions
- GOST 12816-80: Flange technical requirements
- GOST 12820-80: Steel flat loose flanges
- GOST 12821-80: Steel loose plate welded flanges
GOST Pressure Ratings:
- Py ( условное давление): 0.1 to 20.0 MPa
- Common ratings: PN 10, 16, 25, 40 bar
- Temperature classes: -70°C to +600°C
GOST Flange Types:
- Flat welded (Плоские приварные)
- Neck welded (Приварные встык)
- Loose plate (Свободные на приварном кольце)
- Blind flanges (Заглушки)
Steel Flange Material Specifications
Steel flange materials vary by standard:
ANSI Materials:
- ASTM A105 (Carbon steel)
- ASTM A182 F304/F316 (Stainless)
- ASTM A182 F11/F22 (Alloy steel)
DIN Materials:
- 1.0460 (P245GH – Carbon steel)
- 1.4301/1.4401 (Stainless steel)
- 1.5415/1.7335 (Alloy steel)
GOST Materials:
- Ст20 (Carbon steel)
- 12Х18Н10Т (Stainless steel)
- 15Х5М (Alloy steel)
Flange Gasket Compatibility
Proper flange gasket selection must match the flange standard:
- ANSI: ASME B16.20/B16.21 gaskets
- DIN: DIN 2690/2691 gaskets
- GOST: GOST 536/283 gaskets
Conversion Considerations
When interfacing different standards:
- Use adapter flanges or spool pieces
- Verify pressure-temperature compatibility
- Ensure gasket surface compatibility
- Consider bolt size and pattern differences
- Document all conversions for maintenance
Quality Certification Requirements
International projects may require:
- EN 10204 3.1 material certificates
- PED 2014/68/EU compliance (Europe)
- ASME Section VIII (Pressure vessels)
- ISO 9001 quality management
- Third-party inspection reports
Conclusion
Understanding the differences between ANSI flange, DIN flange, and GOST flange standards is essential for successful international projects. Each standard has unique dimensions, pressure ratings, and material specifications that affect pipe flange selection and compatibility.
For expert guidance on international flange standards and steel flange procurement, contact our technical team for project-specific recommendations.

