Pressure Vessel Steel Grades Comparison Guide (ASTM, EN, GB & Equivalent Chart)
In the global industrial supply chain, selecting the right Pressure Vessel Quality (PVQ) steel is critical for the safety and longevity of boilers, heat exchangers, and storage tanks. Because different regions follow different engineering codes-ASTM/ASME (Americas/International), EN 10028 (Europe), and GB 713 (China)-understanding how these grades compare is essential for engineers and procurement specialists.
This guide provides a definitive comparison of pressure vessel steel grades, technical specifications, and equivalent relationships.
1. Key Features of Pressure Vessel Quality (PVQ) Steel
Compared to standard structural steel, PVQ steel is produced under enhanced quality control to meet the stringent requirements of high-pressure fabrication. Its core advantages include:
High Strength: Designed to maintain structural integrity under extreme pressure and temperature.
Excellent Toughness: High impact resistance to prevent catastrophic brittle failure.
Strict Chemical Control: Limits on impurities like Sulfur and Phosphorus to ensure purity.
Enhanced Weldability: Low carbon equivalents for ease of fabrication.
Corrosion Resistance: Often alloyed to withstand oxidation and corrosive chemicals.
Strict Quality Standards: Rigorous testing (UT, HIC, Impact) to comply with safety codes.
Application Versatility: Suitable for everything from cryogenic LNG tanks to high-heat reactors.
2.Market Analysis: Global Standards & Regional Usage
To ensure global compatibility and safety, pressure vessel material grades are standardized by leading international codes. The market is primarily divided by project location, certification requirements (e.g., ASME vs. PED), and specific industry applications.
ASTM / ASME (The Global Standard for Oil & Gas)
Primary Markets: North and South America, Southeast Asia, and the Middle East (GCC region).
Project Type: Most common in ASME-oriented projects, specifically in upstream oil and gas, refineries, and petrochemical plants requiring the ASME "U" stamp.
Typical Grades:
Carbon Steel (Moderate/Low Temp): ASTM A516 (Gr. 60, 65, 70), ASTM A515 (Gr. 60, 70), ASTM A285 Gr. C.
High-Strength (Fine-Grain): ASTM A537 (Class 1, Class 2).
Alloy Steel (High Temp/Creep): ASTM A387 (Gr. 11, Gr. 22, Gr. 91), ASTM A204 (Gr. A, B, C).
Cryogenic Steel (Nickel-Alloy): ASTM A203 (Gr. A, B, D, E).
EN 10028 (European & PED-Certified Projects)
Primary Markets: Europe, Africa, and international EPC (Engineering, Procurement, and Construction) projects led by European firms.
Project Type: Mandatory for projects requiring PED (Pressure Equipment Directive) compliance and CE marking.
Typical Grades:
Non-Alloy (Boiler Steel): P235GH, P265GH, P295GH, P355GH.
Fine-Grain (Low Temp/High Strength): P275NH/NL1, P355NH/NL1/NL2, P460NH.
Alloy Steel (Elevated Temp): 16Mo3, 13CrMo4-5, 10CrMo9-10.
GB / GB/T (The Global Export Supply Chain)
Primary Markets: China domestic market, and global sourcing via Chinese mills for infrastructure projects in Asia, Africa, and CIS countries.
Project Type: Highly cost-effective for large-scale boiler manufacturing and international supply chains utilizing Chinese manufacturing hubs.
Typical Grades:
Boiler & Vessel (Carbon): GB 713 Q245R, Q300R, Q345R (Note: Q345R is the most common export grade).
Low-Temperature Service: GB 3531 16MnDR, 09MnNiDR.
Alloy Steel: GB 713 15CrMoR, 12Cr2Mo1R, 14Cr1MoR.
Quick Selection Insight:
For the Americas & Middle East: Specify ASTM A516 Gr. 70.
For the EU & Africa: Specify EN 10028 P355GH.
For Cost-Effective Global Sourcing: Specify GB 713 Q345R (which often meets A516 Gr. 70 mechanical properties).
This chart compares Yield/Tensile strength, impact energy, and identifies equivalent grades across international codes.
| Standard Category | Grade | Yield / Tensile (MPa) | Impact Toughness | Temp Range | International Equivalents |
| Moderate Temp | A516 Gr. 60 |
≥≥ 220 / 415–550 |
27J @ -20°C |
≤≤ 455°C |
P265GH / Q245R |
| (Boiler/Tank) | A516 Gr. 70 |
≥≥ 260 / 485–620 |
27J @ -20°C |
≤≤ 455°C |
P355GH / Q345R |
| P265GH |
≥≥ 265 / 410–530 |
27J @ 20°C |
≤≤ 450°C |
A516 Gr. 60 / Q245R | |
| Q345R |
≥≥ 345 / 490–610 |
34J @ 0°C |
≤≤ 450°C |
A516 Gr. 70 / P355GH | |
| High Strength | A537 Cl. 1 |
≥≥ 345 / 485–620 |
Normalized |
≤≤ 450°C |
P355NH / Q345R |
| (Fine-Grain) | A537 Cl. 2 |
≥≥ 415 / 550–690 |
Q+T (High) |
≤≤ 450°C |
P355NL2 / Q370R |
| P355NL2 |
≥≥ 355 / 490–630 |
27J @ -50°C |
≤≤ -50°C |
A537 Class 2 / 16MnDR | |
| P460NH |
≥≥ 460 / 570–730 |
-20°C Impact |
≤≤ 450°C |
A612 / Q420R | |
| Alloy Steel | A387 Gr. 11 |
≥≥ 275 / 485–620 |
Cr-Mo Alloy |
≤≤ 600°C |
13CrMo4-5 / 15CrMoR |
| (High Temp) | A387 Gr. 22 |
≥≥ 310 / 620–760 |
Cr-Mo Alloy |
≤≤ 620°C |
10CrMo9-10 / 12Cr2Mo1R |
| 16Mo3 |
≥≥ 280 / 450–600 |
Mo Alloy |
≤≤ 600°C |
A204 Gr. B / 12CrMo | |
| A387 Gr. 91 |
≥≥ 415 / 585–760 |
High Creep |
≤≤ 650°C |
X10CrMoVNb9-1 | |
| Cryogenic | A203 Gr. E |
≥≥ 275 / 485–620 |
3.5% Nickel |
≤≤ -101°C |
12Ni14 / 09MnNiDR |
| (Low Temp) | 16MnDR |
≥≥ 255 / 470–640 |
41J @ -20°C |
≤≤ -40°C |
A516 Gr. 70 (tested) |
| A285 Gr. C |
≥≥ 205 / 380–515 |
Low Strength |
≤≤ 400°C |
- |
Chemical Composition of Key Pressure Vessel Steel Grades
Below is a representative chemical composition comparison of commonly used pressure vessel steel grades:
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | 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 |
3. Pressure Vessel Steel Equivalent Grade Chart (ASTM vs. EN vs. GB)
| Service Category | ASTM / ASME (Americas) | EN 10028 (Europe) | GB Standard (China) | Key Applications |
| Moderate Temp | ASTM A516 Gr. 60 | P265GH | Q245R | Standard boilers & steam drums |
| (Boiler/Tank) | ASTM A516 Gr. 65 | P295GH | Q300R | Intermediate pressure vessels |
| ASTM A516 Gr. 70 | P355GH | Q345R | High-pressure tanks, heat exchangers | |
| ASTM A515 Gr. 70 | P355GH | Q345R | Intermediate/higher-temp boilers | |
| ASTM A285 Gr. C | P235GH | (Approx) Q245R | Low-pressure storage tanks | |
| High Strength | ASTM A537 Class 1 | P355NH | Q345R (Normalized) | Heavy-wall vessels, fine-grain |
| (Fine-Grain) | ASTM A537 Class 2 | P355NL2 | Q370R / 16MnDR | Quenched & Tempered (Q+T) vessels |
| ASTM A612 | P460NH | Q420R | High-strength gas transport tanks | |
| Alloy Steel | ASTM A204 Gr. B | 16Mo3 | 12CrMo | Molybdenum alloy for steam piping |
| (High Temp) | ASTM A387 Gr. 11 | 13CrMo4-5 | 15CrMoR | Chrome-Moly for refineries |
| ASTM A387 Gr. 22 | 10CrMo9-10 | 12Cr2Mo1R | Critical reactors, nuclear power | |
| ASTM A387 Gr. 12 | 13CrMo4-5 | 14Cr1MoR | Intermediate high-temp service | |
| ASTM A387 Gr. 91 | X10CrMoVNb9-1 | 10Cr9Mo1VNb | Ultra-high temperature boilers | |
| Cryogenic | ASTM A516 Gr. 70 (IT) | P355NL1 | 16MnDR | LPG storage (-40°C service) |
| (Low Temp) | ASTM A203 Gr. E | 12Ni14 | 09MnNiDR | 3.5% Nickel-alloy for LNG |
| ASTM A353 | X8Ni9 | 06Ni9DR | 9% Nickel steel for deep cold |
Practical Sourcing Insights for Buyers:
The "A516-70 / Q345R" Relationship:
In the global export market, Q345R is the most widely available Chinese grade. It is frequently certified to meet or exceed ASTM A516 Gr. 70 mechanical properties, making it the top choice for cost-effective international procurement.
PED Compliance (EN Grades):
If your project is located in Europe or requires CE marking, you must specify the EN 10028 grade (e.g., P355GH). Even if the mechanical properties of an ASTM grade match, the European standard requires specific PED certification (Pressure Equipment Directive).
Low-Temperature Toughness:
When looking for "Arctic Service" or low-temp storage, always look for the "NL2" suffix in EN grades (e.g., P355NL2) or the "DR" suffix in GB grades (e.g., 16MnDR). These signify that the material has been impact-tested at -50°C or lower.
Alloy Steel (Chrome-Moly):
ASTM A387 Gr. 11 and Gr. 22 are the global benchmarks for refineries. While 16Mo3 (EN) is extremely popular for heat exchangers due to its excellent balance of cost and creep resistance.
4.Specialized Technical Requirements
HIC Testing for Sour Service (H2S)
For projects in corrosive environments, steel plates must be tested according to NACE TM0284.
Acceptance Criteria: CLR≤5%, CTR≤1.5%, CSR≤0.5%.
Heat Treatment: HIC performance is only guaranteed in the Normalized + PWHT (Post-Weld Heat Treated) condition.
PWHT Cycle: Typically 1 hour/inch @ 1125°F to 1175°F.
Pressure Vessel Quality (PVQ) Advantages
Unlike standard structural plates, PVQ plates (e.g., A516 Gr 70 PVQ) provide:
Strict control of chemical composition (Low S & P).
Enhanced weldability for pressure applications.
Better consistency in mechanical properties across different heats.
5.Material Selection by Application Type
| Industry Application | Recommended Steel Grades |
| Standard Boilers & Steam Drums | A516 Gr. 70, P265GH, Q245R, P295GH |
| Petrochemical High-Pressure Vessels | A387 Gr. 11, A387 Gr. 22, 16Mo3, P355GH |
| Cryogenic LNG & LPG Tanks | 16MnDR, A203 Gr. E, P355NL2, 09MnNiDR |
| Heat Exchangers | 16Mo3, A387 Gr. 11, A515 Gr. 70 |
| Low-Pressure Storage Tanks | A285 Gr. C, A516 Gr. 60, Q245R |
6. Frequently Asked Questions (FAQs)
Q: What is the Chinese equivalent of ASTM A516 Grade 70?
The closest equivalent is Q345R from the GB 713 standard. It offers similar mechanical strength and is the standard choice for Chinese-manufactured export vessels.
Q: When should I choose P355NL2 instead of P355GH?
Both offer 355 MPa yield strength. However, P355NL2 is impact-tested at -50°C, making it essential for low-temperature or Arctic service, whereas P355GH is designed for elevated temperature service.
Q: Why is A537 Class 2 more expensive than A516 Gr 70?
A537 Class 2 is Quenched and Tempered (Q&T), which requires a more complex heat treatment process to achieve significantly higher yield and tensile strength than the Normalized A516.
Q: Does A387 steel protect against corrosion?
ASTM A387 (Chrome-Moly) is designed for heat resistance and creep strength, not primarily for aqueous corrosion. For severe corrosion, stainless steel cladding or specialized alloy elements are required.
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