ASTM -A179/A179M Standard Specification

Scope

1. This specification covers seamless cold-drawn mild steel pipe with minimum wall thickness for use in tubular heat exchangers, condensers, and similar heat exchange equipment.

2. This specification covers steel tubing with an outer diameter of 1/8 inch to 3 inches (3.2 mm to 76.2 mm, inclusive of 1/8 inch and 3 inches).

Note 1—Steel tubing with an outer diameter smaller than that specified in this specification and with a thinner wall thickness may be supplied. Steel tubing with an outer diameter less than 1/8 inch (3.2 mm) or a wall thickness less than 0.015 inch (0.4 mm) is not required to meet mechanical property requirements.

3. Values expressed in inches-pounds or International System of Units (SI) should be considered standard values respectively. SI units are indicated in parentheses in the text. Values in the two systems are not entirely equivalent; therefore, each system must be used independently. Mixing values in both systems may result in non-compliance with this specification. Unless otherwise indicated by “M” in the order, imperial units should be used.

ASTM A179 Steel Grades

ASTM A179/A179M standards cover ASTM A179 Grade A and Grade C steels. These two types of steel differ in mechanical properties and applications, requiring selection based on the operating environment and engineering requirements.

1. ASTM A179 Grade A

ASTM A179 Grade A steel has a minimum yield strength of 35 ksi (240 MPa). Suitable for general industrial light-duty heat exchanger applications, such as heat exchangers and condensers.

2. ASTM A179 Grade C

ASTM A179 Grade C steel has a minimum yield strength of 47 ksi (325 MPa). It features high yield strength and is suitable for high-temperature and high-pressure environments.

ASTM A179 Specifications

ASTM A179/A179M standards strictly adhere to the specifications established by the American Society for Testing and Materials (ASTM).

The ASTM A179/A179M standards provide guidance on parameters such as pipe dimensions and applicable ranges, and offer detailed references for the engineering design and material selection of piping systems.

Standard: ASTM A179

Procedure: SMLS

Dimensions: 3.2mm -76.2mm; 1/8″ – 3″; DN6 – DN80

Thickness: 1.65-7mm

Unit Length: 3000 mm – 25000 mm

Steel Grade: SA179

Surface Coating: Varnishing, Oiling, Hot Dip Galvanizing

End Type: Square Cut, Plain, Bevelled, Threaded, Socket,

Joint Method: Fitting, Flange, Coupling, Clamp, Pipe Shoulder, Welding

Pipe Machining: Welding, Bending, Hole Drilling, Punching, Swaging, Tapering, Flaring, Expanding

Manufacture

Seamless pipes shall be manufactured by seamless process and shall be cold drawn.

1. Heat Treatment

Tubes shall be heat treated after the final cold draw pass at a temperature of 1200°F [650°C] or higher.

2. Surface Condition

Finished tubes shall be free of scale. A slight amount of oxidation will not be considered as scale.

Chemical Composition

The steel shall conform to the following requirements as to chemical composition:

Mechanical Properties of ASTM A179 Pipe

ASTM A179/A179M steel pipes must undergo rigorous mechanical property tests, such as tensile tests, yield tests, and hydrostatic tests, to ensure that the produced mild steel pipes have good tensile strength, yield strength, and elongation, thereby ensuring the stable and safe operation of the pipeline system and meeting the needs of various industrial production.

Mechanical Tests Required

1. Flattening Test

One flattening test shall be made on specimens from each of two tubes from each lot or fraction thereof.

2. Flaring Test

One flaring test shall be made on specimens from each of two tubes from each lot or fraction thereof.

3. Flange Test

When specified as a substitute for the flaring test, for tubes having a wall thickness (actual mean wall) less than 10 % of the outside diameter, one test shall be made on specimens from each of two tubes from each lot.

4. Hardness Testing

Two tubes from each batch shall be sampled for Rockwell hardness testing. The term "batch" refers to all tubes of the same nominal diameter and wall thickness produced from the same furnace before cutting.

When final heat treatment is performed in a batch furnace, a batch shall consist only of tubes of the same dimensions, in the same furnace charge, and heat-treated in the same charge.

When final heat treatment is performed in a continuous furnace, a batch shall consist of all tubes of the same dimensions, in the same furnace charge, at the same temperature, the same holding time, and the same furnace speed.

5. Hydrostatic Testing

Each tube shall be subjected to a hydrostatic test; alternatively, if specified by the buyer, a non-destructive electrical method may be used instead of a hydrostatic test.

Surface Treatment of ASTM A179/A179M Steel Tubes

ASTM A179/A179M steel tubes typically operate under extreme conditions such as high temperature and pressure. Surface coating treatments can improve their corrosion resistance and mechanical properties, thereby extending their service life.

ASTM A179/A179M steel pipe surface coating processes include, but are not limited to, the following:

1. Polished Coating

Polishing the surface of the mild steel pipe to make it smooth and flat, reducing surface defects and roughness.

2. Oil Coating

Applying a protective grease or wax to the surface of the mild steel pipe. This coating is often used for short-term transportation and can effectively reduce surface oxidation and corrosion.

3. Hot-Dip Galvanizing Coating

Immersing the steel plate in a molten zinc solution to form a zinc-iron alloy coating or a pure zinc layer on the steel surface. The zinc layer sacrifices itself to protect the steel. This coating has good stability and is widely used in fields such as shipbuilding.

FAQ

1. What is the difference between ASTM A106 and A179?

A106: High-temperature and high-pressure transport pipe.

A179: Mild steel pipe for heat exchangers and condensers.

The uses are completely different and they are not interchangeable.

2. What is the difference between ASTM A192 and A179?

A192: Boiler high-pressure water pipe.

A179: Heat exchanger tube, emphasizing thermal conductivity.