Key Requirements for Steel Pipes in The Fluid Transport Industry

Requirement Category                  Details

Mechanical Properties                       High yield strength, good ductility (elongation ≥ 20%), impact resistance

                                                            (especially low-temperature toughness)

Weldability                                           Easy field welding, weld strength matching base metal, HAZ toughness compliant

Corrosion Resistance                        External coating required (e.g., 3LPE, FBE); internal lining or coating (cement

                                                            mortar or polymer)

Non-Destructive Testing                   100% ultrasonic + radiographic inspection (seamless), full weld inspection(Welding)

‌Dimensional Accuracy                      Tight tolerances on outer diameter and wall thickness for proper fit-up and Welding

Sealing & Pressure Integrity        Must maintain sealing and structural integrity under design pressure to prevent leakage

Hebei K-Steel Pipe Industry can supply all kinds of steel pipe.

API 5L‌ (Line Pipe Standard, Globally Used)

‌Application‌: Long-distance oil and gas transmission pipelines.

‌Grades‌:

‌Grade B‌: Basic carbon steel, yield strength ≥ 240 MPa

‌X42/X52/X60/X70/X80‌: High-strength line pipe; the number indicates minimum yield strength in ksi (e.g., X70 ≥ 485 MPa)

‌Manufacturing Methods‌: Seamless or welded (ERW, LSAW, SSAW)

‌Features‌: Widely used in onshore and offshore pipelines; requires DWTT for low-temperature toughness verification.

GB/T 9711-2023‌ (Steel Pipes for Petroleum and Natural Gas Industries in China)

‌Application‌: Domestic oil and gas trunk pipeline systems.

‌Technical Equivalence‌: Aligned with API 5L, divided into PSL1 (basic) and PSL2 (enhanced requirements)

‌Typical Materials‌: L245NB / L415MB (equivalent to X42/X70)

‌Requirements‌: PSL2 mandates strict control on chemistry, impact energy, DWTT, and NDT coverage.

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

‌Application‌: High-temperature fluid transport within refineries.

‌Material Properties‌: Carbon <0.30%, Mn 0.29%-1.06%, tensile strength ≥485MPa

‌Advantages‌: Good weldability and thermal stability, suitable for high-load non-long-distance applications.

‌ASTM A53‌ (Welded and Seamless Carbon Steel Pipe)

‌Application‌: Low-pressure fluid transport, plant internal piping, structural supports.

‌Types‌:

‌Type E‌: ERW welded

‌Type S‌: Seamless

‌Grades A/B‌: Grade B is more common with higher strength

‌Use Cases‌: Suitable for medium-low pressure systems, not recommended for high-pressure long-distance transmission.

Polyethylene (PE) Pipes (e.g., PE100)‌

‌Application‌: Urban gas distribution, water supply networks.

‌Standards‌: ISO 4437 (gas), ISO 4427 (water)

‌Features‌:

Corrosion-resistant, flexible, fewer joints

Operating pressure typically ≤ 1.0 MPa

Suitable for low-to-medium pressure, non-high-temperature environments

ASTM A312 / ASME SA312‌ (Austenitic Stainless Steel Pipes)

‌Application‌: High-purity or highly corrosive fluid transport in chemical, pharmaceutical, and food industries.

‌Common Grades‌:

‌TP304/TP304L‌: General-purpose, good corrosion resistance

‌TP316/TP316L‌: Molybdenum-containing, excellent resistance to chloride-induced stress corrosion

‌Features‌: High purity, solution annealed, 100% eddy current + ultrasonic testing.