DIN EN 1092-1 Flange Standard
Comprehensive guide to DIN EN 1092-1 metric flange standards, PN pressure ratings, DN sizing, and international applications
DIN EN 1092-1 Overview
DIN EN 1092-1 (Flanges and their joints - Circular flanges for pipes, valves, fittings and accessories, cast steel) is the European and international metric flange standard. Published by the German Institute for Standardization (Deutsches Institut für Normung) and harmonized with European standardization (CEN), this standard is widely used globally outside North America.
DIN EN 1092-1 uses metric sizing (DN in millimeters) and bar-based pressure ratings (PN), making it fundamentally different from the inch-based ASME B16.5 standard. While both specify similar flange concepts, the specific dimensions, pressure classes, and designations differ, making them incompatible.
Key Characteristics
Metric System
DN (Diamètre Nominale) in millimeters. DN 50, DN 100, etc.
Pressure Nominale (PN)
Bar-based ratings: PN 6, PN 10, PN 16, PN 25, PN 40, PN 63, PN 100
Geographic Scope
Primary standard in Europe, Asia, and most international projects
Flange Types
Six standard types (01-05, 11-13) including WN, SO, SW, LJ, Th, Bl
Why DIN EN 1092-1 Matters
If you're working on international projects, importing equipment from Europe, or operating in EU-regulated industries, you'll encounter DIN EN 1092-1. It's the ISO-harmonized standard used throughout the EU and in many Asian and Middle Eastern applications.
PN Pressure Ratings
DIN EN 1092-1 specifies eleven pressure ratings based on bar (metric SI unit). Each PN rating defines the design pressure and is available across a range of flange sizes. The pressure rating determines flange thickness and material requirements.
PN Rating | Design Pressure (bar) | Design Pressure (PSI) | Size Range | Common Applications |
|---|---|---|---|---|
| PN 6 | 6 bar | 87 PSI | DN 10-2000 | Low-pressure water, HVAC systems |
| PN 10 | 10 bar | 145 PSI | DN 10-2000 | General industrial, water supply |
| PN 16 | 16 bar | 232 PSI | DN 10-2000 | Standard industrial piping |
| PN 25 | 25 bar | 363 PSI | DN 10-1500 | High-pressure industrial systems |
| PN 40 | 40 bar | 580 PSI | DN 10-900 | Very high-pressure service |
| PN 63 | 63 bar | 914 PSI | DN 10-400 | Critical high-pressure applications |
| PN 100 | 100 bar | 1450 PSI | DN 10-250 | Extreme high-pressure service |
| PN 160 | 160 bar | 2320 PSI | DN 10-200 | High-pressure hydraulic and process |
| PN 250 | 250 bar | 3625 PSI | DN 10-150 | Ultra-high-pressure industrial |
| PN 320 | 320 bar | 4640 PSI | DN 10-100 | Specialty high-pressure systems |
| PN 400 | 400 bar | 5800 PSI | DN 10-100 | Maximum-pressure industrial service |
Understanding Bar vs PSI
PN ratings use bar (metric pressure unit). 1 bar ≈ 14.5 PSI. So PN 16 (16 bar) ≈ 232 PSI. This is roughly comparable to ASME Class 300 (330 PSI) but not exactly equivalent.
Quick Conversion:
Bar × 14.5 = PSI
PN 16 × 14.5 = 232 PSI
Selecting the Right PN Rating
- •PN 6-10: Low-pressure utilities, HVAC, water supply
- •PN 16: General industrial piping (most common)
- •PN 25-40: High-pressure industrial systems
- •PN 63-100: Extreme pressure applications (rare)
Temperature Derating: Like ASME standards, higher temperatures reduce flange pressure ratings. DIN provides temperature derating curves. Always verify your operating temperature against the PN rating to ensure adequacy.
DN Metric Sizing System
DIN EN 1092-1 uses DN (Diamètre Nominale) sizing in millimeters, ranging from DN 10 through DN 4000. The DN number approximately corresponds to the internal diameter in millimeters but should not be treated as an exact measurement - always verify actual bore dimensions.
DN (mm) | NPS (inches) | Approximate | Common? |
|---|---|---|---|
| DN 10 | NPS 3/8" | Approx 0.4" | Rare |
| DN 15 | NPS 1/2" | Approx 0.6" | Common |
| DN 20 | NPS 3/4" | Approx 0.8" | Common |
| DN 25 | NPS 1" | Approx 1.0" | Common |
| DN 32 | NPS 1 1/4" | Approx 1.25" | Common |
| DN 40 | NPS 1 1/2" | Approx 1.5" | Very Common |
| DN 50 | NPS 2" | Approx 2.0" | Very Common |
| DN 80 | NPS 3" | Approx 3.0" | Very Common |
| DN 100 | NPS 4" | Approx 4.0" | Very Common |
| DN 150 | NPS 6" | Approx 6.0" | Very Common |
DN vs NPS: Key Differences
DN (Metric)
Size in millimeters. DN 50 = nominally 50 mm diameter.
NPS (Inch)
Nominal pipe size in inches. NPS 2" is nominal only (actual ID ≠ 2").
Conversion
Approximate, never exact. DN 50 ≈ NPS 2" but dimensions differ.
Common DN Sizes
DN 15, 25, 40: Small systems
DN 50, 80, 100: General piping (most common)
DN 150, 200, 250: Large distribution systems
DN 300+: Major transmission lines
DIN EN 1092-1 Flange Types
DIN EN 1092-1 specifies six flange types, designated numerically (Type 01, 02, 05, 11, 12, 13). Each type corresponds to an installation method and structural design.
Type | Designation | Description |
|---|---|---|
| Type 11 | Weld Neck (WN) | Tapered hub with gradual transition. Preferred for high-temperature and high-pressure applications due to excellent fatigue resistance. |
| Type 12/13 | Slip-On (SO) | Flange slips over pipe with two fillet welds. Cost-effective option for lower pressure applications. |
| Type 02/32 | Socket Weld (SW) | Pipe inserts into socket with fillet weld at end. Compact design for small-diameter piping. |
| Type 04 | Lap Joint (LJ) | Loose flange on stub end. Allows rotation and interchangeability; economical for frequent changes. |
| Type 13 | Threaded (Th) | Pipe threads into flange bore. Used where welding is not possible or practical. |
| Type 05 | Blind/Cap (Bl) | Solid flange with no bore. Used to cap pipe ends or isolate portions of system. |
DIN EN 1092-1 vs. ASME B16.5
While both DIN EN 1092-1 and ASME B16.5 specify industrial flanges, they are fundamentally different standards with incompatible dimensions and designations.
Parameter | DIN EN 1092-1 | ASME B16.5 |
|---|---|---|
| Sizing System | Metric (DN in millimeters) | Inch-based (NPS in inches) |
| Pressure Ratings | PN (Pressure Nominale) 6-100 bar | Pressure Classes 150-2500 PSI |
| Geographic Usage | Europe, Asia, most international | North America, some international |
| Face Types | Raised Face standard; Ring Joint available | FF, RF, RJ, T&G all specified |
| Temperature Range | -10°C to 350°C (-14°F to 662°F) | -20°F to 850°F (varies by material) |
| Material Standards | Per DIN/EN specs (DIN 1.0495 = C22) | Per ASTM specs (ASTM A105 = C22) |
| Bolt Pattern | Different from ASME; not interchangeable | Standard across all ASME sizes |
When to Use DIN EN 1092-1
- →European projects or EU standards required
- →International equipment with metric dimensions
- →Asian manufacturing facilities or partners
- →ISO/DIN metric piping systems
- →When specified in contract or design code
Key Incompatibilities
- ✗Bolt hole patterns differ; won't align
- ✗Gasket seating surfaces incompatible
- ✗Face types designated differently
- ✗Dimensions metric vs imperial (not convertible)
- ✗Pressure rating bases different (bar vs PSI)
Critical Rule: Never Mix Standards
Do not use DIN flanges with ASME equipment or vice versa. If your project requires both standards, use engineered adapter spools or transition pieces designed for that specific application. Mixing standards will result in leaks, failures, and safety hazards.
Frequently Asked Questions
Common questions about DIN EN 1092-1 flange standards
Need DIN EN 1092-1 Flanges?
We supply metric flanges for international projects. Our team can help you select the right PN rating, DN size, and material for your application.