PN16, PN40, PN100 vs ANSI Class: What Is the Difference Between PN and Class Ratings?

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PN16, PN40, PN100 vs ANSI Class: What Is the Difference Between PN and Class Ratings?

15/04/2026

🔷 What is PN in piping systems?

PN (Pressure Nominal) is a nominal pressure rating system used under the European EN standard. It defines the pressure capacity of valves, flanges, and piping components at a reference temperature.

Common PN ratings include: PN6, PN10, PN16, PN25, PN40, PN64, PN100.

👉 Simply put:

Higher PN = higher pressure capacity
However, actual pressure depends on temperature and material

PN16, PN40, PN100 vs ANSI Class: What Is the Difference Between PN and Class Ratings?

⚙️ What do PN16, PN40, PN100 mean?

Common PN ratings:

PN16: approx. 16 bar (commonly used for water, HVAC systems)
PN40: approx. 40 bar (steam, oil, light industrial systems)
PN100: approx. 100 bar (high-pressure industrial systems)

⚠️ Note: These values are based on standard conditions. Pressure capacity decreases as temperature increases.

🔄 What is the difference between PN and ANSI Class?

Both PN and ANSI Class are pressure rating systems, but they differ in measurement systems and standards.

Criteria	PN (Europe)	ANSI Class (USA)
Unit	Bar	Non-fixed Class system
Standard	EN (European)	ASME / ANSI
Definition	Nominal pressure	Pressure-temperature rating
Region	Europe, Vietnam	USA, Oil & Gas industry

📊 PN vs ANSI Class comparison (approximate)

PN	Equivalent ANSI Class	Applications
PN16	Class 150	HVAC, water systems
PN25	Class 150–300	Light industry
PN40	Class 300	Steam, oil systems
PN64	Class 600	Heavy industry
PN100	Class 600–900	High-pressure systems

⚠️ This is only an approximate comparison, not an exact conversion.

📐 Why PN and Class cannot be directly converted?

The differences come from:

🔥 Operating temperature effects
🧱 Material grades (A105, F304, F316, etc.)
📏 Different design standards (EN vs ASME)
⚙️ Different safety calculation methods

👉 Therefore, PN and Class cannot be directly converted 1:1.

🏭 When to use PN or ANSI Class?

PN (EN standard):
- Water systems, HVAC, general industrial use
- Projects in Vietnam and Europe
ANSI Class (ASME standard):
- Oil & gas, chemical, power plants
- International high-pressure applications

❌ Common mistakes

Assuming PN16 = exactly Class 150
Directly converting PN to Class without considering temperature
Mixing PN and Class in the same piping system

🏁 Conclusion

PN16, PN40, PN100 and ANSI Class ratings are important standards used to define pressure capacity in piping systems.

👉 Key takeaways:

PN = European standard (bar-based)
Class = ASME standard (temperature-dependent)
No exact 1:1 conversion
Selection must consider pressure + temperature + material

📞 Contact Information

PHUC MINH ENGINEERING – pm-e.vn provides industrial valves, flanges, gaskets, and piping accessories according to international standards.

🌐 Website: pm-e.vn
📧 Email: info@pm-e.vn
📱 Hotline: +84 907 450 506 – +84 902 720 814 – +84 902 800 728

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