ASTM A53 Standard specification covers Seamless and Welded, Black and Hot-Dipped Galvanized nominal (average) wall pipe for coiling, bending, flanging and other special purposes and is suitable for welding.

The steel for both seamless and welded pipe shall be made by one or more of the following processes: open-hearth, electric furnace, or basic-oxygen. The weld seam of electric-resistance welded pipe in Grade B shall be heat treated after welding.

A53 pipe comes in three types and two grades

• A53 Type F, which is longitudinally furnace butt welded or continuous welded (Grade A only)
• A53 Type E, which is longitudinally electric resistance welded (Grades A and B)
• A53 Type S, which is seamless pipe, produced by hot working, and possibly cold finishing, the steel (Grades A and B). ASTM A53, Type S is now currently an outdated specification and has been replaced by ASTM A106 specification for seamless carbon steel pipe.

This is a standard set by the standards organization ASTM International, a voluntary standards development organizations that sets technical standards for materials, products, systems, and services.

This specification covers Seamless and Welded, Black and Hot-Dipped Galvanized nominal (average) wall pipe for coiling, bending, flanging and other special purposes and is suitable for welding. Continuous-Welded pipe is not intended for flanging. Purpose for which pipe is intended should be stated on order. It shall be permissible to furnish pipe having other dimensions provided that such pipe complies with all other requirements of this specification. Supplementary requirements of an optional nature are provided and shall apply only when specified by the purchaser.

Note 1. The dimensionless designators NPS (nominal pipe size) [DN (diameter nominal)] have been substituted in this specification for such traditional terms as ‘nominal diameter,’ ‘size,’ and ‘nominal size.’

Note 2. The term nominal wall thickness has been assigned for the purpose of convenient designation, existing in name only, and is used to distinguish it from the actual wall thickness, which may vary over or under the nominal wall thickness.

Permissible Variations in Wall Thickness

The minimum wall thickness at any point shall not be more than 12.5% under the nominal wall thickness specified.

Permissible Variations in Weights per Foot

Weight of any length shall not vary more than 10% over and 3.5% under that specified.

NOTE-NPS 4 and smaller-weighed in lots. Larger sizes shall be weighed separately by length.

The total composition for these five elements shall not exceed 1.00%.

Hydrostatic testing

Hydrostatic inspection test pressures for plain end and threaded and coupled pipe are specified. Hydrostatic pressure shall be maintained for not less than 5 seconds for all sizes of seamless and electric-resistance-weld pipe.

Mechanical tests specified

• Tensile Test — Transverse required on ERW for NPS 8 and large.
• Sending Test (Cold) — STD and XS-NPS 2 and under XXS-NPS 1 1/4 and under.

Flattening Test — NPS 2 and larger STD and XS. (Not required for XXS pipe.)