🌐Flange Standards Breakdown – ANSI vs DIN vs JIS: Which One Fits Your Engineering Needs?

Flanges (法蘭) are crucial components in piping systems, used to connect pipes, valves, pumps, and other equipment. Selecting the right flange standard ensures compatibility, safety, and long-term performance—especially for projects involving international specifications.

In this post, we break down the three most common flange standards:
ANSI (ASME) from the U.S., DIN from Germany, and JIS from Japan. We’ll also highlight their sub-specifications and usage differences.

🔧 1. ANSI / ASME Flange Standards (🇺🇸)

ANSI (often in practice referred to as ASME, the American Society of Mechanical Engineers) is the most widely used flange standard in the oil & gas, petrochemical, and industrial sectors.

✅ Key Features:

·         Inch-based sizing

·         Designed for high-pressure, high-temperature environments

·         Commonly used in heavy industry

·         Compatible with NPT (threaded pipe) systems

✅ Key Sub-Standards:

 🔹 Pressure Classes:

• 150, 300, 600, 900, 1500, 2500 lbs

🔹 Common Materials:

• Carbon steel, stainless steel, alloy steel

🔩 2. DIN Flange Standards (🇩🇪)

DIN (Deutsches Institut für Normung) flanges are widely used in Europe and internationally, especially in chemical processing and mechanical engineering.

✅ Key Features:

• Metric system (millimeters)
• Pressure-based classification (PN)
• Excellent for precision manufacturing and process industry usage

✅ Common DIN Standards:

🔹 Pressure Ratings (PN):

• PN6, PN10, PN16, PN25, PN40, PN64, PN100, PN160…

✅ Note: "PN" (Pressure Nominal) = pressure in bars
E.g., PN16 = 16 bar ≈ 232 psi

🔧 3. JIS Flange Standards (🇯🇵)

JIS (Japanese Industrial Standards) are commonly used in Japan and Southeast Asia, especially in HVAC, plumbing, food, and general industry.

✅ Key Features:

• Uses metric measurements
• Pressure classification is in K (kgf/cm²)

✅ Common JIS Flange Standards:

🔹 Pressure Ratings:

• 5K, 10K, 16K, 20K, 30K

✅ Note: 10K ≈ 10 kgf/cm² ≈ 142 psi
JIS flanges typically have a lighter design than ANSI or DIN.

📐 ANSI vs DIN vs JIS: Comparison Table

Some of customers might confuse,
"Can ANSI and JIS flanges be connected directly?"

❌ No. Flanges from different standards—such as ANSI and JIS—are not dimensionally compatible, even if they share the same nominal pipe size (NPS).
Key differences include:

·         Bolt hole patterns

·         Bolt circle diameters

·         Center bore dimensions

These variations mean that direct connection is not possible without using an adapter flange or making modifications to the piping design.

🧠 Conclusion: Choosing the Right Flange

Whether you're engineering a plant in the U.S., Europe, or Asia, understanding flange standards is essential for ensuring compatibility and compliance. Here’s a quick guide:

• ✅ Use ANSI/ASME for oil & gas or heavy industry
• ✅ Use DIN for European manufacturing and process systems
• ✅ Use JIS for light-duty or Asian plumbing/HVAC applications

🛠 Need Help?

If you're unsure which standard suits your project, our engineering team is ready to help.
Contact us today for flange sizing, material selection, and technical support!

📧 Email us at: sales@ansonflow.com

🌐 Visit: https://www.ansonflow.com/