Selecting the correct steel plate is critical for the safety and performance of pressure equipment. This guide provides a clear comparison of key pressure vessel steel grades from major international standards-ASTM, EN, and GB-to help engineers and buyers make informed decisions for projects like boilers, reactors, and LNG tanks.
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1. What Are Pressure Vessel Steel Grades?
Pressure vessel steel grades are specialized classifications that guarantee the required strength, toughness, and weldability for containers operating under high pressure. They are engineered to prevent failure in critical applications across oil & gas, power generation, and chemical processing industries.
Key properties of pressure vessel steel material
- High tensile strength and toughness
- Good resistance to creep and fatigue
- Excellent weldability and formability
Applications of Pressure Vessel Steel Plates
2. International Pressure Vessel Steel Standards
To ensure global compatibility and safety, pressure vessel material grades are standardized by leading international codes. The most recognized are ASTM, EN, and GB.
- ASTM (U.S.): The global benchmark. Key standards: A516 (carbon steel), A387 (alloy steel), ASTM A285 (lower strength pressure vessels)
- EN (Europe): Governed by EN 10028. Common grades: P265GH, P355GH,16Mo3, 13CrMo4-5.
- GB (China): Standard GB 713 is predominant. Common grades: Q245R, Q345R, 16MnDR.
3. Key Grades: Side-by-Side Comparison
Understanding PVQ Steel: Pressure Vessel Quality (PVQ) steel, like A516 Gr.70 PVQ, denotes enhanced testing and impact toughness for critical ASME applications.
Below is a comparison of major pressure vessel steel plate grades from ASTM, EN, and GB standard
| Grade | Standard | Yield / Tensile (MPa) | Elongation (%) | Impact | Temp | Equivalent | Recommended Applications |
| A516 Gr.60 | ASTM | ≥220 / 415–550 | ≥21 | 27J @ -20°C | ≤455°C | EN P265GH / GB Q245R | Boilers, moderate-pressure tanks |
| A516 Gr.70 | ASTM | ≥260 / 485–620 | ≥21 | 27J @ -20°C | ≤455°C | GB Q345R | High-pressure boilers, heat exchangers |
| A285 Gr.C | ASTM | ≥205 / 380–515 | ≥20 | Low | ≤400°C | - | Low-pressure storage tanks |
| A387 Gr.11 | ASTM | ≥275 / 485–620 | ≥20 | Good @ high temp | ≤600°C | - | Petrochemical, power plant vessels |
| A387 Gr.22 | ASTM | ≥310 / 620–760 | ≥19 | High-temp creep | ≤620°C | - | Reactors, high-pressure systems |
| P265GH | EN 10028 | ≥265 / 410–530 | ≥22 | 27J @ 20°C | ≤450°C | ASTM A516 Gr.60 | Boilers, European pressure vessels |
| P355GH | EN 10028 | ≥355 / 470–630 | ≥22 | 27J @ 20°C | ≤450°C | ASTM A516 Gr.70 | High-pressure components, energy sector |
| 16Mo3 | EN 10028 | ≥280 / 450–600 | ≥22 | 27J @ RT | ≤600°C | - | Heat exchangers, steam pipes |
| Q245R | GB 713 | ≥245 / 400–520 | ≥21 | 31J @ 0°C | ≤450°C | ASTM A516 Gr.60 | General pressure vessels, boilers |
| Q345R | GB 713 | ≥345 / 490–610 | ≥21 | 34J @ 0°C | ≤450°C | ASTM A516 Gr.70 | Thick-walled vessels, high-strength tanks |
| 16MnDR | GB 3531 | ≥255 / 470–640 | ≥22 | 41J @ -20°C | ≤-40°C | - | Cryogenic LNG tanks, low-temp vessels |
4. Chemical Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Notes |
| A516 Gr.60 | 0.21 | 0.55–1.30 | ≤0.40 | ≤0.035 | ≤0.035 | – | – | Carbon steel |
| A516 Gr.70 | 0.27 | 0.85–1.20 | ≤0.40 | ≤0.035 | ≤0.035 | – | – | Stronger version of A516 Gr.60 |
| A387 Gr.11 | 0.12–0.20 | 0.30–0.60 | ≤0.50 | ≤0.035 | ≤0.035 | 1.00–1.50 | 0.44–0.65 | Cr-Mo alloy steel |
| P265GH | ≤0.20 | 0.80–1.60 | ≤0.40 | ≤0.025 | ≤0.020 | – | – | EN non-alloy boiler steel |
| P355GH | ≤0.22 | 1.00–1.70 | ≤0.50 | ≤0.025 | ≤0.020 | – | – | Higher strength EN grade |
| Q245R | ≤0.20 | ≤1.20 | ≤0.50 | ≤0.025 | ≤0.015 | – | – | Chinese std, A516 Gr.60 equiv. |
| Q345R | ≤0.20 | ≤1.70 | ≤0.50 | ≤0.025 | ≤0.015 | – | – | Closer to A516 Gr.70 |
5. How to Choose the Right Grade: A Quick Guide
Follow this two-step selection matrix based on primary service conditions.
By Temperature:
- -50°C to 400°C: Carbon steels (A516 Gr.70, P355GH, Q345R).
- 400°C to 600°C: Alloy steels (A387 Gr.11/22, 16Mo3).
- Below -20°C (Cryogenic): Toughness-guaranteed grades (16MnDR, impact-tested A516).
By Application:
- Boilers / General Vessels: A516 Gr.70 / Q345R / P355GH
- High-Temp Reactors: A387 Gr.11 / 16Mo3
- LNG Storage Tanks: 16MnDR
- Low-Cost Storage Tanks: A285 Gr.C / Q245R
6. Frequently Asked Questions
Q: Is P265GH equivalent to A516 Gr.60 or Gr.70?
P265GH is comparable to A516 Gr.60 in terms of pressure vessel applications, but the exact composition and standards differ. For projects requiring EN standards, P265GH is preferred; for ASME-coded vessels, A516 Gr.60/70 is standard.
Q: What steel is best for LNG tank construction?
A: 16MnDR (GB) or impact-tested A516/A537 (ASTM) are specified for their guaranteed toughness at cryogenic temperatures.
Q: Why choose alloy steel like A387 Gr.11?
A: For service above 400°C where carbon steel weakens. It provides superior creep strength and resistance to hydrogen attack.
Q: What is the main Chinese grade for pressure vessels?
A: Q345R (GB 713) is the most common grade for general pressure vessels, analogous to A516 Gr.70.
7. Conclusion
Choosing the correct pressure vessel steel plate-whether ASTM A516, EN P355GH, or GB Q345R-is fundamental to integrity and safety.
Match the grade to your specific temperature, pressure, and code requirements. For specialized applications like cryogenic LNG storage or high-temperature reactors, alloy and low-temperature grades are essential.
Need help selecting the right grade for your project? Contact us at your convenience.
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