Key Requirements for Steel Pipes in Pressure Vessels And Special Applications

Requirement Category                        Details

Material Properties                                    High creep strength, oxidation resistance, corrosion resistance, low-                                                                                    temperature toughness

Manufacturing Process                            Primarily seamless, hot-rolled or cold-drawn, with heat treatment                                                                                        (normalizing, tempering)

Chemical Composition                             Strict control of C, Mn, P, S, Cr, Mo to prevent brittle fracture

Non-Destructive Testing                           Ultrasonic, eddy current, radiographic testing to ensure defect-free integrity

Mechanical Testing                                    Tensile, impact, flattening, flaring, hydrostatic tests

Microstructural Stability                            Uniform grain size, no decarburization, absence of harmful phase                                                                                         precipitation

Hebei K-Steel Pipe Industry can categarize the steel pipe 

ASTM A106‌ (Seamless Carbon Steel Pipe for High-Temperature Service)

• ‌Application‌: High-pressure and high-temperature fluid transmission, such as in power plant boilers and refineries.

• ‌Grades‌:

  • ‌Grade A‌: Tensile strength ≥ 415 MPa

  • ‌Grade B‌ (most common): Tensile strength ≥ 485 MPa, yield strength ≥ 240 MPa

  • ‌Grade C‌: Higher strength for extreme conditions

• ‌Features‌: Seamless manufacturing, capable of withstanding temperatures up to 750°C; widely used in oil, chemical, and power industries.

• ASTM A335 / ASME SA335‌ (Alloy Steel Seamless Pipe for High-Temperature Service)

  • ‌Application‌: High-temperature and high-pressure equipment like superheaters and reheaters.

  • ‌Common Grades‌:

    • ‌P1 (T1)‌: Cr-Mo steel, heat-resistant up to ~595°C

    • ‌P5 (T5)‌: 5%Cr-0.5%Mo, excellent creep resistance

    • ‌P9 (T9)‌: 9%Cr-1%Mo, used in supercritical units

  • ‌Requirements‌: Must undergo normalizing and tempering to ensure microstructural stability and long-term strengthASTM A213 / ASME SA213‌ (Seamless Ferritic and Austenitic Alloy Steel Tubes for Boiler, Superheater, Heat Exchanger)

  •      Application‌: Boilers, superheaters, condensers, and heat exchangers.

  • Material Types‌:

  • Austenitic Stainless Steels‌: e.g., TP304, TP316 — excellent corrosion resistance

  • Ferritic/Martensitic Stainless Steels‌: e.g., T22, T91 — resistant to high-temperature oxidation

  • Requirements‌: High purity, controlled grain size, and non-destructive testing (ultrasonic, eddy current).

  • GB/T 5310-2023‌ (Chinese Standard for Seamless Steel Tubes for High-Pressure Boilers)

    ‌Application‌: Critical components in supercritical and ultra-supercritical power plant boilers.

    ‌Typical Materials‌:

    ‌20G‌: High-quality carbon steel for medium-pressure boilers

    ‌15CrMoG, 12Cr1MoVG‌: Low-alloy heat-resistant steels for high-temperature and high-pressure environments

    ‌Requirements‌: Implemented since April 1, 2024, with stricter controls on chemical composition, grain size, decarburization layer, and ultrasonic inspection.

  • EN 10216-2 / BS EN 10216-5‌ (European Standards for Seamless Steel Tubes for Pressure Purposes)

    ‌EN 10216-2‌: Non-alloy and alloy steels for high-temperature pressure equipment.

    ‌EN 10216-5‌: Stainless steel seamless tubes for corrosive media.

    ‌Example Materials‌:

    ‌P235GH, P265GH‌: Good high-temperature performance

    ‌1.4401 (316), 1.4404 (316L)‌: Corrosion-resistant stainless steels

    ‌Requirements‌: Compliant with the Pressure Equipment Directive (PED), must pass hydrostatic, flaring, and flattening tests.

  • ASTM A333 Gr.6‌ (Seamless Steel Pipe for Low-Temperature Service)

    ‌Application‌: Liquefied natural gas (LNG), cryogenic equipment.

    ‌Properties‌:

    Tensile strength ≥ 415 MPa, yield strength ≥ 240 MPa

    Impact energy ≥ 18J at -45°C, excellent low-temperature toughness

    ‌Use Cases‌: LNG pipelines, cryogenic reactors, liquid nitrogen/oxygen storage and transport.