Specifications

Chemical composition and mechanical properties

The ASTM A106 requirements for Grades A, B and C are shown; Grade B is the one normally specified.

Limits on combined Cr, Cu, Mo, Ni and V, and the manganese allowance for lower carbon, are as given in the standard.

Elongation requirements depend on specimen type and wall thickness, as given in the standard.

Common sizes – Schedule 40 and 80

Outside diameters and wall thicknesses from ASME B36.10M for frequently ordered sizes. The full table for all sizes and schedules is in our pipe schedule chart.

Sour service and IBR options

For wet sour service containing hydrogen sulphide, A106 Grade B pipe can be supplied to NACE MR0175 / ISO 15156 on request, with the hardness limits and controls the standard requires; please state this in the enquiry. For steam and boiler piping in India subject to the Indian Boiler Regulations, pipe is supplied with IBR certification when the order requires it, with the mill documents and inspection arranged accordingly.

A106, A53 or API 5L?

ASTM A106 is the plant-piping standard for seamless carbon steel pipe at elevated temperature. ASTM A53 covers seamless and welded pipe for general pressure use, and API 5L covers line pipe for pipelines. Because Grade B in all three has similar chemistry and the same minimum strength, mills often certify one pipe to all three standards, which lets a single stock pipe meet different specifications. A106 Grade C, with higher strength, is used for selected high-pressure lines, and A333 Grade 6 replaces A106 where low-temperature toughness is required.

Testing, marking and ordering

A106 pipe is tested for chemistry, tensile and bend or flattening properties, and each length receives a hydrostatic or non-destructive electric test. Pipes are marked with the specification, grade, size, schedule, heat number and the mill's identification. Please give the size, schedule, length, end finish, coating, quantity and any NACE MR0175 / ISO 15156, IBR, impact or inspection requirement.

Applications and related products

A106 Grade B pipe is used for process and hydrocarbon lines, steam and condensate, boiler feed water, compressed air, firewater and utility piping in refineries, petrochemical and fertiliser plants, power stations and oil and gas facilities. It is matched with A234 WPB butt-weld fittings, A105 flanges and B7/2H bolting; see carbon steel seamless pipes for other grades, the carbon steel page for material guidance and the seamless pipes and tubes page for other materials.