ASTM A106 / ASME SA106 Seamless Pipes: Technical Standard and Specifications

Technical Specifications and Scope of ASTM A106 / ASME SA106 Standard

The ASTM/ASME A/SA 106 specification governs the manufacturing of seamless carbon steel pipes intended for high-temperature and high-pressure service. Products are available in a range of sizes from NPS 1/8″ to NPS 48″ (DN 6 – DN 1200) with nominal wall thicknesses compliant with ASME B 36.10M (including schedules 10 through 160, STD, XS, XXS). EV Group China supplies pipes meeting these parameters, with the capability to adapt to non-standard dimensions while adhering to the core requirements of the specification.

This type of steel pipe exhibits high ductility, making it suitable for bending, flanging, and various welding methods. Key areas of application include the energy sector, construction of boiler installations, high-pressure steam lines, as well as facilities in the petrochemical and gas processing industries. The choice of welding technology must be verified based on the steel grade and calculated operational loads.

Note: When designing, the risk of material graphitization should be taken into account.

Note: The terminology NPS (Nominal Pipe Size) and DN (nominal diameter) within this standard are equivalent to traditional nominal size designations.

For critical structures requiring enhanced performance characteristics, additional tests are provided, which should be agreed upon during the order placement stage at EV Group China.

The standard allows for the use of both SI units and inch-pound units. Values in different systems are not direct mathematical equivalents; therefore, mixing parameters from different systems is not permitted.

Pipes with diameters from NPS 1-1/2″ may be produced by either hot-forming or cold-drawing methods. Products NPS 2″ and larger are supplied in a hot-finished condition unless otherwise specified.

Manufacturing Technology

The pipes are manufactured using steel produced in open-hearth, basic-oxygen, or electric-arc furnaces, followed by degassing and refining. The metal is cast into ingots or strand-cast billets. Hot-finished pipes are supplied without additional heat treatment, while cold-drawn products must undergo mandatory thermal annealing.

Chemical Composition of ASTM A106 / ASME SA106 Steel Grades

Mechanical Properties

Quality Control and Testing

Hydrostatic testing is conducted at a pressure equal to 60% of the specified minimum yield strength (SMYS), but not exceeding 2500 psi for NPS 3 and 2800 psi for larger diameter pipes. The hold time under pressure is at least 5 seconds.

Mechanical tests include tension tests (longitudinal/transverse) and bend tests (cold method) for pipes NPS 2 and larger.

Dimensional and Geometric Tolerances

The wall thickness deviation must not exceed -12.5% of the nominal value. The weight tolerance is ±10% for a single pipe and ±3.5% for a lot. The outside diameter must comply with the regulatory tables of the standard.

Product Marking

Each batch of pipes from EV Group China is marked with tags indicating the manufacturer, steel grade (Grade A, B, C), hydrostatic test data, pipe weight, and additional “S” requirements if applicable.