Pressure Vessel Steel Plate Standards Explained: ASME vs EN vs GB
A pressure vessel project often begins with one simple question:
Which material standard should we use?
Some drawings specify ASME SA516 Grade 70, while others require EN 10028 P355GH or China's GB/T 713 Q345R. Although these grades may appear similar, they follow different design codes, testing requirements and certification systems. Understanding these pressure vessel steel standards helps avoid specification mistakes and unnecessary costs during procurement.
1. Why Different Pressure Vessel Standards Exist
It's not that one standard is better than another. Rather, different regions developed their own pressure vessel design codes based on local manufacturing practices, safety regulations, and historical engineering approaches.
- ASME — Dominates North America and is widely adopted in the Middle East and Southeast Asia for international projects.
- EN — The standard of choice for pressure equipment in Europe under the PED (Pressure Equipment Directive).
- GB — Used for domestic projects in China and increasingly for Chinese-invested overseas facilities.
📌 What we see in practice: An EPC in the Middle East almost always specifies ASME. A European fabricator will default to EN. And a Chinese manufacturer bidding on a domestic project will use GB. The key is knowing which standard applies to your project before you send out the inquiry.
2. ASME Pressure Vessel Steel Standards
ASME (American Society of Mechanical Engineers) standards are the most widely recognized globally, particularly for projects in North America and the Middle East. The most common ASME pressure vessel steel plate grades include:
- SA516 Grade 70 — The industry standard for moderate and lower-temperature pressure vessels.
- SA387 — Chrome-moly alloy steel for high-temperature service.
- SA537 — Quenched and tempered steel for higher strength requirements.
💡 Why EPCs prefer ASME: ASME Section VIII is recognized by most international classification societies and engineering firms. If your project is exported, ASME is usually the safest choice. The certification process is well-established, and the material quality documentation (EN 10204 3.1/3.2) is widely accepted.
3. EN Pressure Vessel Steel Standards
EN 10028 is the European standard for pressure vessel steels. European projects typically follow the Pressure Equipment Directive (PED) 2014/68/EU, and the steel plates must meet EN 10028 material specifications. Common EN pressure vessel steel grades include:
- P265GH — Equivalent to SA516 Gr.60, used for general pressure vessel applications.
- P355GH — Equivalent to SA516 Gr.70, the most widely used EN pressure vessel steel.
- 16Mo3 — Molybdenum-alloyed grade for high-temperature service.
- 13CrMo4-5 — Chrome-moly grade for elevated temperature applications.
💡 Why European clients prefer EN: The PED requires that materials have a European standard designation. EN 10028 materials come with comprehensive test reports and material certificates that are accepted across all EU member states.
4. GB Pressure Vessel Steel Standards
GB/T 713 is the Chinese national standard for pressure vessel steels. It replaced the earlier GB 713 and now covers a broader range of grades. Common GB pressure vessel steel grades include:
- Q245R — The Chinese equivalent to SA516 Gr.60 and P265GH.
- Q345R — The Chinese equivalent to SA516 Gr.70 and P355GH. This is the most widely used GB pressure vessel steel.
- Q370R — Higher strength grade for more demanding applications.
- 16MnDR — Low-temperature grade with guaranteed impact toughness at -40°C.
💡 Why Chinese manufacturers use GB: GB/T 713 materials are domestically produced, cost-effective, and readily available. For projects in China or Chinese-invested overseas facilities, GB standards are often specified. When equivalence is accepted, Q345R can replace SA516 Gr.70 — but this must be approved by the design engineer.
5. Comparison of ASME, EN and GB Standards
Here's a quick reference for procurement teams comparing pressure vessel material standards:
6. Equivalent Steel Grades Across Different Standards
One of the most common questions buyers ask is whether grades from different standards are interchangeable. The short answer is: they are approximate equivalents, not exact copies. Always verify with the design engineer before substituting.
⚠️ Important: While Q345R is often referred to as the Chinese equivalent of SA516 Grade 70, the impact test temperature, carbon equivalent, and delivery condition requirements may differ. Substitution requires approval from the responsible design engineer.
📌 Note: These are approximate equivalents for reference only. Always confirm with the applicable design code and the mill test certificate.
7. Which Standard Should You Choose?
The right standard depends on your project, not on which standard is "best." Here's a practical guide:
- Middle East EPC project → ASME (SA516 Grade 70 is usually specified)
- European pressure equipment → EN (P355GH or P265GH, following PED)
- Chinese domestic fabrication → GB (Q345R is the standard choice)
- International project with no regional preference → check the design code specified by the EPC. Some accept ASME equivalents, others require EN.
💡 Our experience: We've supplied ASME plates to EPCs in the UAE, EN plates to European fabricators, and GB plates to Chinese domestic projects. The material itself is often produced from the same steel melts. The difference is in the testing, documentation, and certification required by each standard. The key is knowing what the project design code requires — and sticking to it.
8. Common Mistakes When Comparing Steel Standards
❌ Mistake 1: Assuming Q345R = SA516 Grade 70
They are approximate equivalents, not identical. The design code, impact temperature, and certification requirements may differ. Always check with the engineer before substituting.
❌ Mistake 2: Ignoring the heat treatment requirement
SA516 Gr.70 is often specified in normalized condition for low-temperature service. Q345R may be supplied as-rolled unless normalized is requested. The delivery condition must be confirmed on the MTC.
❌ Mistake 3: Not verifying the impact test temperature
ASME SA516 Gr.70 is typically tested at -46°C. GB Q345R is tested at 0°C by default, with -20°C available on request. If your project requires -46°C, you must specify it clearly.
❌ Mistake 4: Not checking MTC format requirements
Some projects require EN 10204 Type 3.2 certificates with third-party inspection. Others accept Type 3.1. Confirm the MTC format with the customer before production.
9. Frequently Asked Questions
❓ Is Q345R equivalent to SA516 Grade 70?
They are widely considered approximate equivalents for many pressure vessel applications. However, the design code, impact temperature, and certification requirements may differ. Substitution requires approval from the design engineer.
❓ Is P355GH stronger than Q345R?
P355GH and Q345R have similar tensile strength ranges (485–620 MPa vs 510–640 MPa). Q345R typically has higher minimum yield strength (345 MPa vs 355 MPa for P355GH, which is slightly higher by name but similar in practice). The difference is negligible for most designs.
❓ Which standard is accepted in the Middle East?
ASME is the most widely accepted standard in the Middle East, particularly for oil and gas projects. Most EPCs in the region specify ASME SA516 Grade 70 as the default pressure vessel steel plate.
❓ Can EN steel replace ASME steel?
Yes — but only if the design code permits it. P355GH is often accepted as an equivalent to SA516 Gr.70, but this must be specified in the project documentation. Substitution without approval is not recommended.
❓ Why do EPC companies specify ASME?
ASME Section VIII is recognized globally. EPC firms prefer ASME because it reduces project risk — the standards are well-established, the material testing is consistent, and the certification process is accepted by most classification societies and insurance companies.
❓ Which pressure vessel standard is most commonly used worldwide?
ASME is the most globally recognized standard for pressure vessels. However, the most common standard depends on the region — ASME in North America and the Middle East, EN in Europe, and GB in China.
❓ Are material certificates different for each standard?
Yes. ASME projects typically require ASME-compliant MTCs with U-stamp traceability. EN projects require EN 10204 Type 3.1 or 3.2 certificates. GB projects follow Chinese inspection standards. Always confirm the MTC format required by the project.
❓ Can one mill produce multiple standards?
Yes — many steel mills can produce plates to ASME, EN, and GB standards from the same production line. The difference is in the testing, documentation, and certification. A reputable supplier will be able to offer multiple standards with proper certification.
10. Final Thoughts
Instead of looking for the "best" standard, buyers should first identify the design code required by the project.
Once the design code is confirmed, selecting the corresponding pressure vessel steel grade becomes much more straightforward. This approach helps avoid unnecessary material substitutions and certification issues during fabrication.
💡 Our view: We've supplied ASME, EN, and GB pressure vessel steel plates to projects across the Middle East, Europe, and Southeast Asia. In our experience, the most successful projects are those that confirm the design code and material standard before placing the order — not after.
📚 Further Reading & Standards
- 🔗 SA516 Grade 70 – Product Page
- 🔗 Q345R Steel Plate – Product Page
- 🔗 Q345R vs SA516 Grade 70 – Comparison Guide
- 🔗 How to Choose Pressure Vessel Steel Plate – Buyer's Guide
- 📄 ASME SA-516/SA-516M, EN 10028-2:2017, GB/T 713.2-2023
Need ASME, EN or GB Pressure Vessel Steel Plates?
CEHE STEEL supplies SA516 Gr.70, Q345R, P355GH and other pressure vessel steel grades with full certification.