Your comprehensive guide to industry standards and technical specifications for pipe flanges
Flange standards establish the specifications, dimensions, and performance requirements for pipe flanges used across industries worldwide. Understanding the right standard for your application ensures compatibility, safety, and regulatory compliance. Whether you're working with North American (ASME/ANSI), European (DIN/EN), water industry (AWWA), or oil and gas (API) standards, we provide detailed specifications to guide your selection and procurement decisions.
ASME
Scope
Steel pipe flanges, fittings, and valves
Size Range
NPS 1/2" - 24"
Pressure Ratings
150, 300, 400, 600, 900, 1500, 2500 PSI
Materials
Carbon Steel, Stainless Steel, Alloy Steel
Applications
Petroleum, Petrochemicals, Power Generation, Chemical Processing
ASME
Scope
Large diameter steel flanges
Size Range
NPS 26" - 60"
Pressure Ratings
Series A: 75, 150 PSI | Series B: 150, 300 PSI
Materials
Carbon Steel, Forged Steel
Applications
Offshore, Pipeline, Refining, Large Industrial Systems
AWWA
Scope
Steel pipe flanges for waterworks (zinc-coated)
Size Range
4" - 144"
Pressure Ratings
Class B, D, E, F
Materials
Carbon Steel (Zinc-Coated)
Applications
Water Transmission, Water Distribution, Utility Systems
AWWA
Scope
Stainless steel pipe flanges for waterworks
Size Range
2" - 72"
Pressure Ratings
Class 125, 150, 200 PSI
Materials
Stainless Steel
Applications
Corrosive Water Environments, High-Chloride Applications, Saltwater Systems
DIN / European Standards
Scope
Metric flanges for industrial applications
Size Range
DN 10 - DN 4000
Pressure Ratings
PN 6 - PN 100
Materials
Carbon Steel, Stainless Steel, Nodular Iron
Applications
European Industrial, ISO Metric Systems, International Projects
API
Scope
Large diameter carbon steel flanges
Size Range
Up to 120" OD
Pressure Ratings
150, 300, 600, 900, 1500 PSI
Materials
Carbon Steel
Applications
Crude Oil, Natural Gas, Petrochemical, Large Diameter Pipelines
MSS
Scope
Steel pipeline flanges
Size Range
NPS 1" - 24"
Pressure Ratings
Class 150 - 2500 PSI
Materials
Carbon Steel
Applications
General Piping, Industrial Systems, Utility Infrastructure
ANSI
Scope
Cast iron flanges
Size Range
Various sizes
Pressure Ratings
Class 25, 125, 250 PSI
Materials
Cast Iron
Applications
General Purpose, Low-Pressure Systems, Legacy Applications
North American standards widely used in petroleum, petrochemical, and industrial applications. Cover a wide range of sizes and pressure ratings.
ASME B16.5
ASME B16.47
MSS SP-44
ANSI B16.1
Specialized for water industry applications. Include both carbon steel (zinc-coated) and stainless steel options for corrosion resistance.
AWWA C207
AWWA C228
European and global standards using metric dimensions. DIN EN 1092-1 is essential for international projects and ISO metric systems.
DIN EN 1092-1
| Standard | Sizing | Pressures | Applications |
|---|---|---|---|
| ASME B16.5 | Nominal Pipe Size (NPS) | 150-2500 PSI | Petroleum, Chemical, Power |
| ASME B16.47 | NPS 26"-60" | 75-300 PSI | Large Diameter, Offshore |
| MSS SP-44 | NPS 1"-24" | 150-2500 PSI | Industrial Piping |
| ANSI B16.1 | Cast Iron | 25-250 PSI | Low-Pressure, General Use |
| Standard | Sizing | Pressures | Applications |
|---|---|---|---|
| AWWA C207 | 4"-144" | Classes B-F | Water Transmission |
| AWWA C228 | 2"-72" | 125-200 PSI | Corrosive Water |
| DIN EN 1092-1 | DN 10-4000 | PN 6-100 | European/ISO Metric |
| API 605 | Up to 120" OD | 150-1500 PSI | Oil & Gas |
Determine if your project follows North American (ASME/ANSI), European (DIN/EN), or international standards.
Identify your industry (water, petroleum, chemical, power) and specific application requirements.
Consider pressure ratings, temperature ranges, and corrosion resistance needs.
Ensure flanges match existing equipment, piping systems, and connection standards.
Check local codes, industry standards, and regulatory compliance requirements for your region.
| Industry | Primary Standards | Common Sizes | Key Considerations |
|---|---|---|---|
| Petroleum & Gas | ASME B16.5, ASME B16.47, API 605 | 1/2" - 120" | High pressure, temperature extremes |
| Water Supply | AWWA C207, AWWA C228 | 2" - 144" | Corrosion resistance, zinc coating |
| Chemical Processing | ASME B16.5, ASME B16.47 | 1/2" - 24" | Chemical compatibility, stainless options |
| Power Generation | ASME B16.5, MSS SP-44 | 1" - 24" | High temperature, pressure stability |
| European Industrial | DIN EN 1092-1 | DN 10 - DN 4000 | Metric sizing, ISO compliance |
| General Industry | ASME B16.5, ANSI B16.1, MSS SP-44 | 1/2" - 24" | Cost-effective, widely available |
Our experts at ASME Flanges are ready to assist you in choosing the right flanges for your application.