Standard
Specification |
ASTM A-139-XX (XX= Represents year of last revision) Electric-Fusion Arc- Welded Steel Pipe – NPS 4 or More |
Scope |
This specification covers five grades of electric-fusion (arc)-welded straight-seam or spiral-seam steel pipe in 4" to 92" inclusive with wall thickness up to 1 " inclusive.
Pipe having other dimensions may be furnished provided such pipe complies with all other requirements of this specification and the grades of steel of the manufactured pipes. The pipe is intended for conveying liquid, gas, or vapor. |
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Steel Fabrication Proces |
The steel shall be made by one or more of the following processes :
Martin / Bessemer -open hearth furnace, basic-oxygen or electric-furnace. |
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Chemical Composition |
The steel shall conform to the following chemical requirements:
Chemical Composition %
Grade A Grade B Grade C Grade D Grade E
Carbon ..... 0.30 0.30 0.30 0.30
Manganese 1.00 1.00 1.20 1.30 1.40
Phosphorus .035 .035 .035 .035 .035
Sulfur .035 .035 .035 .035 .035 |
Mechanical Properties |
Grade A Grade B Grade C Grade D Grade E
Yield strength, min, ksi (MPa) 30(205) 35(240) 42(290) 46(315) 52(360)
Tensile strength, min, ksi (MPa) 48(330) 60(415) 60(415) 60(415) 66(455)
% min. elongation/ 2" 35 30 25 23 22 |
Hydrostatic Test |
Each length of pipe shall be tested by the manufacturer to a hydrostatic pressure that will produce in the pipe wall a stress of not less than 60% of the minimum specified yield point at room temperature.
The pressure shall be determined by the following equation : P=2St/D
P= hydrostatic test pressure, psi (not to exceed 2800 psi) 1
S= 0.60 to 0.85 times the minimum yield point of the grade of steel (lb/sq. in.)
t = specified wall thickness, inches
D= specified outside diameter
1 When the diameter and wall thickness of pipe are such that the capacity limits of testing equipment are exceeded by these requirements, the test pressures may be reduced by agreement between the purchaser and the manufacturer. |
Time of Test |
Test pressure shall be held for not less than 5 sec., or for a longer time as agreed upon between the purchaser and the manufacturer.
When agreed upon by the purchaser and the manufacturer and so stated on the order, pipe may be tested :
to 1 1/2 times the working pressure with condition it does not exceed 2800-psi, nor shall the maximum fiber stress exceed 85% of minimum yield point of the grade of steel used.
to a fiber stress which does not exceed 85% of the minimum yield point of the grade of steel used or exceed 2800-psi test pressure. |
Permissable Variations in Weights and Dimension
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Weight
The weight of any length of pipe shall not vary more than 10% over the specified weight.
The weight of any length of pipe shall not vary more than 5% under the specified weight when the specified wall thickness is 0.188" or less or more than 5.5% under when the wall thickness is greater than 0.188".
Thickness
The minimum wall thickness at any point shall be not more than 12.5% under the nominal wall thickness.
Circumference
The pipe shall be substantially round. The outside circumference of the pipe shall not vary more than 1.0%, but not exceeding ¾ in. from the nominal outside circumference based upon the diameter specified, except that the circumference at ends shall be sized, if necessary, to meet the requirements of Section 15.
Straightness
Finished pipe shall be commercially straight. When specific straightness requirements are desired, the order should so state and be agreed upon between the purchaser and the manufacturer. |
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Lengths |
The tolerance of the specified lengths is of ± ½². |
Finish of the End |
Pipe shall be furnished with an angle cut of 90° or beveled ends as specified. All burrs at the ends of pipe shall be removed. When pipe ends have to be beveled for the welding, the ends shall be beveled on the outside to an angle of 35° with a tolerance of ± 2½° and with a width of root face 1/16" ± 1/32". |
Finish of the Pipes |
The repair by manual or automatic arc welding of defects in the pipe wall will be permitted, provided their depth does not exceed 33% the specified wall thickness.
Defects in the welds, such as sweats or leaks, shall be repaired or the piece rejected at the option of the manufacturer. Repairs of this nature shall be made by completely removing the defect, cleaning the cavity, and then welding. All repaired pipe shall be subject to hydrostatic testing. |
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Number of Production Test Specimens |
One longitudinal tension test specimen shall be made from the steel of each heat, or fraction thereof, used in the manufacture of the pipe.
One reduced-section production weld test specimen shall be taken from a length of pipe from each lot of 3000 ft. of pipe, or fraction thereof, of each size and wall thickness. |
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Marking |
Each section of pipe shall be marked with the manufacturer’s distinguishing marking, the specification number, the grade of pipe, and other marking if required and agreed upon between the purchaser and the manufacturer. |
