Pressure Vessel Steel Plate: Why Q345R and ASTM A516 Gr70 Are Widely Chosen by Global Buyers?

When it comes to manufacturing storage tanks and pressure vessels, material selection is one of the most critical decisions. The steel plate must withstand pressure, temperature cycles, welding processes and long-term service conditions — and it must be accepted by the governing design code and the client’s quality system.

That is why tank fabricators and EPC contractors worldwide keep returning to two workhorse grades: Q345R (Chinese GB/T 713) and ASTM A516 Grade 70 (ASME SA-516). But why are these two grades so popular — and how do buyers actually pick between them?

Q345R — The Trusted Pressure Vessel Grade in Chinese & GB-Spec Markets

Q345R is a Chinese pressure vessel steel plate supplied to GB/T 713 – Pressure Equipment Steel Plates and Strips (GB/T 713-2023, superseding GB 713-2014 “Boiler and Pressure Vessel Steel Plates”). The designation is easy to decode: Q = yield strength (qufu), 345 = minimum yield strength of 345 MPa (up to 16 mm thickness), R = pressure vessel (rongqi).

Guaranteed mechanical properties (per GB/T 713; verify against the current edition):

• Impact: Charpy V-notch testing at 0 °C as specified in GB/T 713 (energy values per the applicable edition)

• Design temperature (GB/T 150.2): approximately -20 °C to 475 °C, thickness-dependent

• Delivery conditions: hot-rolled, controlled-rolled or normalized, per the standard

Why buyers like it:

• Excellent combination of strength and weldability at a competitive price

• Mature, proven supply from Chinese mills with fast lead times

• Full documentation: MTC, heat/plate traceability, third-party inspection

• Ideal for projects whose specifications accept Chinese GB standards

Typical applications: oil storage tanks, chemical storage vessels, LPG tanks and spherical storage tanks (GB 12337), and general pressure equipment designed to GB/T 150 and related Chinese codes.

Note on code compatibility: Q345R is accepted under the Chinese code system (GB/T 150, GB/T 16507, GB 12337). For vessels built to ASME BPVC or API standards, Q345R is not a recognized direct substitute — SA-516 Grade 70 is the internationally recognized counterpart, and any cross-standard grade equivalence must be assessed case by case with the client and the design institute.

ASTM A516 Gr70 — The Global Workhorse for Moderate- & Lower-Temperature Service

ASTM A516/A516M Grade 70 (ASME SA-516/SA-516M Grade 70) is arguably the most widely recognized pressure vessel carbon steel plate in the world. The “70” denotes a minimum tensile strength of 70 ksi (485 MPa). It is the standard choice in projects following ASTM/ASME/API specifications across oil & gas, petrochemical, energy and storage tank industries.

Guaranteed mechanical properties (per ASTM A516/A516M):

• Toughness: Charpy V-notch testing is specified as Supplementary Requirement S5 — temperature and energy per the purchaser’s specification; common tank practice covers design temperatures down to about -29 °C (-20 °F)

• Design temperature: moderate- and lower-temperature service per the standard’s scope; ASME design temperature typically up to about 480 °C (900 °F)

• Delivery conditions: hot-rolled, controlled-rolled, normalized or normalized-and-tempered per ASTM A20/A516

Why buyers like it:

• Globally recognized by engineering companies, EPC contractors and third-party inspectors

• Proven toughness and weldability for moderate- and lower-temperature service

• Available with MTC, third-party inspection (SGS / BV / TÜV, etc.) and full project documentation

• The default grade for API 620 / API 650 storage tanks and ASME BPVC Section VIII Div. 1 vessels

Q345R vs A516 Gr70: How Do Buyers Choose?

The choice is rarely about “which is stronger” — it is about which standard system governs the project:

Practical selection guidance:

• Project standard first: GB-spec projects → Q345R; ASTM/ASME/API-spec projects → A516 Gr70
• Design temperature & toughness: for lower-temperature duties (e.g., below about -20 °C at minimum design temperature), verify the impact testing requirement — A516 Gr70 with S5 impact at the specified temperature, or an impact-tested variant, as applicable
• Certification & traceability: confirm inspection scope up front (MTC, third-party witnessing, UT, dimensional tolerance class)
• Ask the supplier for a recommendation: a professional steel supplier should not only provide plates, but help customers select the suitable grade according to the governing code, service conditions and certification requirements

More Than Steel Plates: Supporting Your Storage Tank Projects

At GNEE Steel, we supply pressure vessel and storage tank steel plates for tank and equipment manufacturers, including:

• Q345R pressure vessel plates (GB/T 713)

• ASTM A516/A516M Gr70 plates (ASME SA-516)

• Boiler and pressure vessel steels per GB/T 713 / ASTM A516

• Cutting and customized processing services

• Mill test certificates, third-party inspection and documentation support

From raw material supply to customized processing, we help tank manufacturers and EPC contractors build reliable solutions for demanding projects.

📩 If you are sourcing storage tank plates or pressure vessel steel, feel free to contact us.

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All data refer to the applicable standard edition at the time of ordering; the mill test certificate and the governing design code shall prevail.