1.1 This specification covers two grades of electric-resistance-welded steel pipe in NPS 2 to NPS 30 (DN 50 to DN 750) inclusive, with nominal (average) wall thickness up to 0.500 in. [12.70 mm], inclusive, and in nominal sizes NPS ¾ to NPS 5 (DN 20 to DN 125) inclusive with nominal (average) wall thickness 0.083 in. [2.11 mm] to 0.134 in. [3.40 mm], depending on size. Pipe having other dimensions (Note 1) may be furnished provided such pipe complies with all other requirements of this specification. The pipe is intended for conveying gas, vapor, water or other liquid; only Grade A is adapted for flanging and bending (Note 2). The suitability of pipe for various purposes is somewhat dependent upon its dimensions, properties, and conditions of service, so that the purpose for which the pipe is intended should be stated in the order. The pipe may be furnished either nonexpanded or cold expanded at the option of the manufacturer. When pipe is cold expanded, the amount of expansion shall not exceed 1.5 % of the outside diameter pipe size.

NOTE 1—A comprehensive listing of standardized pipe dimensions is contained in ASME B36.10M.

NOTE 2—This provision is not intended to prohibit the cold bending of Grade B pipe.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

3.1 For definitions of terms relating to steel manufacturing and properties, refer to Terminology A941.

3.2 For definitions of terms relating to mechanical testing, refer to Terminology E6.

3.3 Definitions of Terms Specific to This Standard:

• burn, n—a rough or sharp edge left on pipe ends by cutting or sawing.
• lot, n—all pipe of the same size, wall thickness and rolled length that is produced from the same heat of steel and subject to the same heat treatment.
• black thread, n—a thread crease exhibiting the original pipe surface after machining.

4.1 Orders for material under this specification should include the following, as required, to describe the desired material adequately:

1. Quantity (feet, metres, or number of lengths),
2. Name of product (electric-resistance-welded pipe),
3. Specification designation and year of issue,
4. Grade (see Table 1),
5. Size (nominal size, NPS [DN], or outside diameter, and nominal wall thickness),
6. Length (specific or random, see 12.4),
7. End finish (plain or threaded, see 13.2),
   • Threaded and coupled, if specified,
   • Threads only, if specified,
   • Plain end, if specified,
8. Alternative electric test (see Section 11),
9. Tension test specimen (see Section 15),
10. Heat analysis, if required (see 6.1),
11. Special requirements.

5.1 The steel shall be made by either or both of the following processes: basic-oxygen or electric-furnace.

5.2 Steel may be cast in ingots or may be strand cast. When steels of different grades are sequentially strand cast, identification of the resultant transition material is required. The producer shall remove the transition material by any established procedure that positively separates the grades.

5.3 The pipe shall be manufactured from flat rolled steel in individual lengths or in continuous length by electric-resistance or electric-induction welding without the addition of extraneous material.

5.4 The weld seam of electric-resistance welded pipe to Grade B pipe shall be heat treated after welding to a minimum temperature of 1000 °F [540 °C] or processed in such a manner that no untempered martensite remains.

6.1 The steel shall conform to the requirements prescribed in Table 2, based on the heat analysis. When specified in the order, the heat analyses shall be reported to the purchaser or a representative of the purchaser.

7.1 An analysis may be made by the purchaser on samples of pipe selected at random and shall conform to the requirements specified in Table 2. Methods and Practices relating to chemical analysis shall be in accordance with Test Method, Practices, and Terminology A751.

8.1.1 The material shall conform to the requirements as to tensile properties prescribed in Table 1.

8.1.2 The yield strength shall be determined by the offset method utilizing 0.2% of the gauge length or by the total extension under load method using 0.5% of the gauge length.

8.1.3 Longitudinal test specimens shall be full-size longitudinal test specimens (see Figure A2.1 of Test Methods and Definitions A370) or longitudinal strip test specimens (see Specimen No. 4 in Fig. A2.3 of Test Methods and Definitions A370).

8.2 The test specimen taken across the weld shall show a tensile strength not less than the minimum tensile strength specified for the grade of pipe ordered. This test will not be required for pipe under NPS 8 [DN 200].

9.1 A specimen at least 4 in. [100 mm] in length shall be flattened cold between parallel plates in three steps with the weld located either 0° or 90° from the line of direction of force as required in 9.2. During the first step, which is a test for ductility of the weld, no cracks or breaks on the inside or outside surfaces shall occur before the distance between the plates is less than two thirds of the original outside diameter of the pipe. As a second step, the flattening shall be continued. During the second step, which is a test for ductility exclusive of the weld, no cracks or breaks on the inside or outside surfaces shall occur before the distance between the plates is less than one third of the original outside diameter of the pipe but is not less than five times the wall thickness of the pipe. During the third step, which is a test for soundness, the flattening shall be continued until the specimen breaks or the opposite walls of the pipe meet. Evidence of laminated or unsound material or of incomplete weld that is revealed during the entire flattening test shall be cause for rejection.

9.2 For pipe produced in single lengths, the flattening test specified in 9.1 shall be made on both crop ends cut from each length of pipe. The tests from each end shall be made alternately with the weld at 0° and at 90° from the line of direction of force. For pipe produced in multiple lengths, the flattening test shall be made on crop ends representing the front and back of each coil with the weld at 90° from the line of direction of force, and on two intermediate rings representing each coil with the weld 0° from the line of direction of force.

9.3 Surface imperfections in the test specimen before flattening, but revealed during the first step of the flattening test, shall be judged in accordance with the finish requirements in Section 13.

9.4 Superficial cracks as a result of surface imperfections shall not be cause for rejection.

10.1 Except as provided for in 10.3, each length of pipe shall be hydrostatically tested at the mill, without leakage through the wall, to a pressure calculated from the following equation:

where:

• P — minimum hydrostatic test pressure, psi, [kPa]. The test pressure need not exceed 2500 psi [17 200 kPa].
• S — allowable fiber stress 18 000 psi [124 000 kPa] for Grade A and 21 000 psi [145 000 kPa] for Grade B. This does not prohibit testing at higher pressure at the manufacturer's option.
• t — specified wall thickness, in. [mm], and
• D — specified outside diameter, in. [mm].

Plain end pipe may be tested at the discretion of the manufacturer in single lengths or in multiple lengths.

10.2 The hydrostatic pressure shall be maintained for not less than 5 s.

10.3 When specified in the order, pipe may be furnished without hydrostatic testing, and each length so furnished shall include with the mandatory marking the letters "NH."

Note 3—This provision is not intended to apply to light wall (Schedule 10) pipe listed in Table X1.1.

10.4 When the hydrostatic test has been omitted, the certification shall clearly state "Not Hydrostatically Tested." The specification number and material grade, as shown on the certification, shall be followed by the letters "NH."

11.1 As an alternate to the hydrostatic test, and when accepted by the purchaser, each pipe shall be tested with a nondestructive electric test. Except for pipe produced on a hot-stretch reducing mill, the weld seam of each length of pipe shall be tested with a nondestructive test in accordance with Practices E213, E273, E309, or E570. Each length of pipe produced on a hot-stretch-reducing mill shall be tested with a nondestructive electric test that inspects the full volume of the pipe in accordance with Practices E213, E309, or E570.

11.2 Recognized methods for meeting this test are electromagnetic (eddy current) or ultrasonic.

11.3 The following information is for the benefit of the user of this specification:

• 11.3.1 The ultrasonic examination referred to in this specification is intended to detect longitudinal imperfections having a reflective area similar to or larger than the reference notch. The examination may not detect circumferentially oriented imperfections of short, deep imperfections.
• 11.3.2 The eddy-current examination referenced in this specification has the capability of detecting significant imperfections, especially of the short, abrupt type.
• 11.3.3 The hydrostatic test referred to in Section 10 is a test method provided for in many product specifications. This test has the capability of finding imperfections of a size permitting the test fluid to leak through the tube wall and may be either visually seen or detected by a loss of pressure. This test may not detect very tight, through-the-wall imperfections or imperfections that extend an appreciable distance into the wall without complete penetration.
• 11.3.4 A purchaser interested in ascertaining the nature (type, size, location, and orientation) of imperfections that can be detected in the specific application of these examinations should discuss this with the manufacturer of the tubular product.

11.4 In order to accommodate the various types of nondestructive electric testing equipment and techniques in use, the calibration pipe shall contain, at the option of the producer, any one or more of the following discontinuities to establish a minimum sensitivity level for rejection:

• 11.4.1 Drilled Hole—A hole not larger than 0.031-in. [0.8-mm] diameter shall be drilled radially and completely through pipe wall, preferably in the weld area, care being taken to avoid distortion of the pipe while drilling.
• 11.4.2 Transverse Tangential Notch—A notch shall be filed or milled tangential to the surface and transverse to the longitudinal axis of the pipe preferably in the weld area. Said notch shall have a depth not exceeding 12.5% of the nominal wall thickness of the pipe or 0.004 in., [0.10 mm], whichever is greater.
• 11.4.3 Longitudinal Notch—A notch 0.031 in. [0.8 mm] or less in width shall be machined in a radial plane parallel to the pipe axis on the outside surface of the pipe preferably in the weld area, to have a depth not exceeding 12.5% of the nominal wall thickness of the pipe or 0.004 in. [0.10 mm], whichever is greater.

11.5 Pipe producing a signal equal to or greater than the calibration imperfection shall be rejected.

12.1 Weight (Mass)—The weight (mass) of any length of pipe other than Schedule 10 shall not vary more than 3.5% under or 10% over that specified, but the carload weight (mass) shall be not more than 1.75% under the nominal weight (mass). The weight (mass) of pipe furnished to Schedule 10 shall not vary more than ±10% from that calculated using the weight (mass) per unit length prescribed in Appendix Table X1.1. The weight (mass) of the pipe shall be calculated from the relevant equation in ASME B36.10M.

12.2 Diameter—The outside diameter shall not vary more than ±1% from the nominal size specified.

12.3 Minimum Wall Thickness—The minimum wall thickness at any point shall be not more than 12.5% under the specified wall thickness.

Note 5—The minimum wall thickness on inspection is shown in Table X1.2 of the Appendix.

12.4 Lengths:

12.4.1 Except as allowed in 12.4.2, pipe shall be furnished in lengths averaging 38 ft [11.6 m] or over, with a minimum length of 20 ft [6.1 m], but no more than 5% may be under 32 ft [9.8 m]. Jointers made by welding are permissible. When threaded pipe is ordered, jointers shall be made by threaded connections and shall not exceed 5% of the order.

12.4.2 Unless otherwise specified, Schedule 10 pipe shall be between 16 and 22 ft [4.9 and 6.7 m] for a minimum of 90% of the footage furnished, with any balance being shorter lengths at least 8 ft [2.4 m] long.

13.1 The finished pipe shall be reasonably straight and free of defects. Surface imperfections in excess of 12.5% of the nominal wall thickness shall be considered defects.

13.2 End Finish:

13.2.1 Schedule 10 Pipe—Pipe furnished to Schedule 10 shall be plain end only. All inside and outside cutting burrs shall be removed. This generally involves breaking the corners.

13.2.2 Ends, Plain End Pipe—Unless otherwise specified, plain end pipe for use with the Dresser or Dayton type coupling shall be reamed both outside and inside sufficiently to remove all burrs. Plain end pipe for welding shall be beveled on the outside to an angle of 30° with a tolerance of +5° and -0° and with a width of flat at the end of the pipe of 1/16 ± 1/32 in. [1.6 ± 0.8 mm]. When material is ordered beveled to any other than a 30° angle, it should be understood that the angle is to be measured from a line drawn perpendicular to the axis of the pipe. This means that a greater amount of material is removed with a 60° angle than with a 30° angle. Pipe shall be sufficiently free from indentations, projections, or roll marks for a distance of 8 in. [200 mm] from the end of the pipe to make a tight joint with the rubber gasket type of coupling. All plain end pipe intended for Dresser or Dayton type joints or for welding, sizes NPS 10 [DN 250] and smaller in outside diameter specified, shall be not more than 1/32 in. [0.8 mm] smaller than the outside diameter specified for a distance of 8 in. [200 mm] from the ends of the pipe and shall permit the passing for a distance of 8 in. [200 mm] of a ring gauge that has a bore 1/16 in. [1.6 mm] larger than the outside diameter specified of the pipe. Sizes larger than NPS 10 [DN 250] shall be not more than 1/32 in. [0.8 mm] smaller than the nominal outside diameter for a distance of 8 in. [200 mm] from the end of the pipe and shall permit the passing for a distance of 8 in. [200 mm] of a ring gauge which has a bore 1/16 in. [1.6 mm] larger than the nominal outside diameter of the pipe.

13.2.3 Ends, Threaded Pipe—Each end of threaded pipe shall be reamed to remove all burrs. All threads shall be in accordance with the American National Standard Pipe Threads (Note 6) and cut so as to make a tight joint when the pipe is tested at the mill to the specified internal hydrostatic pressure. The variation from the standard, when tested with the standard working gauge, shall not exceed one and one-half turns either way. Pipe shall not be rounded by hammering in order to get a full thread. There shall be not more than two black threads for ¾-in. (19.0-mm) taper among the perfect threads. Black threads should not be confused with imperfect threads, such as those torn, shaven, or broken.

Note 6—A complete description of the American National Standard Pipe Threads applicable to pipe, valves, and fittings is contained in ASME B1.20.1: also "Screw-Thread Standards for Federal Services, 1942," National Bureau of Standards Handbook H 28, January, 1942, the pertinent data in both sources being identical.

13.3 Couplings—Each length of threaded pipe shall be provided with one coupling manufactured in accordance with Specification A865/A865M except that the coupling may be wrought iron (Note 7). Threads shall be cut so as to make a tight joint. Taper-tapped couplings shall be furnished on all weights (masses) of threaded pipe NPS 2½ [DN 65] and larger.

Note 7—For sizes NPS 2 [DN 50] and smaller, it is commercial practice to furnish straight-tapped couplings for standard-weight (mass) (Schedule 40) pipe and taper-tapped couplings for extra-strong (Schedule 80) and double-extra-strong pipe. If taper-tapped couplings are required for sizes NPS 2 [DN 50] and smaller on standard weight (mass) (Schedule 40) pipe, line pipe in accordance with Specification 51 of the American Petroleum Institute should be ordered, thread lengths to be in accordance with ASME B1.20.1. Taper-tapped couplings for sizes NPS 2 [DN 50] and smaller in standard weight (mass) may be used on mill-threaded standard weight (mass) type of the same size.

13.4 Protective Coating:

13.4.1 After the pipe has been subjected to the hydrostatic test, and if required by the purchaser, it shall be thoroughly cleaned of all dirt, oil, grease, loose scale, and rust; then dried, and given a protective coating of the kind and in the manner specified by the purchaser. Pipe furnished to Schedule 10 shall be normally shipped with a light coating of processing oil. If so specified, the pipe can be given a mill coating or a special coating.

14.1 Welding Repair:

14.2 Defects in the pipe wall, provided their depth does not exceed one third the specified wall thickness, shall be repaired by electric welding. Defects in the welds such as sweats or leaks, unless otherwise specified, 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 electric welding.

14.3 All repaired pipe shall be retested hydrostatically in accordance with Section 10.

15.1.1 Samples for chemical analysis, except for spectrochemical analysis, shall be taken in accordance with Practice E1806. The number of samples shall be determined as follows:

15.2.1 One longitudinal tension test shall be made on one length (Note 8) from each lot of 400 lengths or fraction thereof of each size under NPS 8 [DN 200] and one transverse body and one transverse weld tension test on one length from each lot of 200 lengths or fraction thereof of each size NPS 8 to NPS 20 [DN 200 to DN 500] and on one length from each lot of 100 lengths or fraction thereof of each size over NPS 20 to NPS 30 [DN 500 to DN 750]. When taken from the skelp, the number of tests shall be determined in the same manner as when taken from the finished pipe.

Note 8—Length is defined as the length as ordered, except that in the case of orders for cut lengths shorter than double random, which is defined as the length as rolled, prior to cutting to the required short lengths.

15.3.1 When pipe is produced in single length, the flattening test specified in 9.1 shall be made on both crop ends cut from each length of pipe. When pipe is produced in multiple lengths, flattening tests are required on the crop ends from the front and back ends of each coil and on two intermediate rings representing each coil.

15.4.1 Each length of pipe shall be subjected to the hydrostatic test specified in Section 10.

16.1.1 If the results of the analysis of either length of pipe does not conform to the requirements specified in Section 7, analyses of two additional lengths from the same lot shall be made, each of which shall conform to the requirements specified.

16.2.1 The test specimens and the tests required by this specification shall conform to those described in Test Methods and Definitions A370, except that all specimens shall be tested at room temperature.

16.2.2 The longitudinal tension test specimen shall be taken from the end of the pipe, or by agreement between the manufacturer and the purchaser may be taken from the skelp, at a point approximately 90° from the weld, and shall not be flattened between gauge marks. The sides of each specimen shall be parallel between gauge marks. At the manufacturer's option, the tension test may be made on full section of pipe.

16.2.3 Transverse weld test specimens shall be taken with the weld at the center of the specimen. Transverse body test specimens shall be taken opposite to the weld. All transverse test specimens shall be approximately 1½ in. [38 mm] wide in the gauge length and shall represent the full wall thickness of the pipe from which the specimen was cut.

16.2.4 If any test specimen shows defective machining or develops flaws not associated with the quality of the steel or the welding, it may be discarded and another specimen substituted.

16.2.5 If the results of the tension tests of any lot do not conform to the requirements specified in 9.1, retests of two additional lengths from the same lot shall be made, each of which shall conform to the requirements specified.

16.2.6 If the percentage of elongation of any tension test specimen is less than that specified in 8.1, and any part of the fracture is more than ¾-in. [19.0-mm] from the center of the gauge length as indicated by scribe scratches marked on the specimen before testing, the specimen may be discarded and another substituted.

16.3.1 Specimens for flattening tests shall be smooth at the ends and free from burrs.

16.3.2 If any section of the pipe fails to comply with the requirements of 9.1, for pipe produced in single lengths, other sections may be cut from the same end of the same length until satisfactory tests are obtained, except that the finished pipe shall not be shorter than 80% of its length after the initial cropping; otherwise, the length shall be rejected. For pipe produced in multiple lengths, retests may be cut from each end of each individual length in the multiple; such tests shall be made with the weld alternately 0° and 90° from the line of direction of force.

16.4 All specimens shall be tested at room temperature.

17.1 The inspector representing the purchaser shall have free entry, at all times while work on the contract of the purchaser is being performed, to all parts of the manufacturer's works that concern the manufacture of the material ordered. The manufacturer shall afford the inspector, without charge, all reasonable facilities to satisfy him that the material is being furnished in accordance with this specification. All tests (except check analysis) and inspection shall be made at the place of manufacture prior to shipment, unless otherwise specified, and shall be so conducted as not to interfere unnecessarily with the manufacturer's operation.

18.1 Each length of pipe received from the manufacturer may be inspected by the purchaser and, if it does not meet the requirements of this specification based on the inspection and test method as outlined in the specification, the length may be rejected and the manufacturer shall be notified. Disposition of rejected pipe shall be a matter of agreement between the manufacturer and the purchaser.

18.2 Pipe found in fabrication or in installation to be unsuitable for the intended use, under the scope and requirements of this specification, may be set aside and the manufacturer notified. Such pipe shall be subject to mutual investigation as to the nature and severity of the deficiency and the forming or installation, or both, conditions involved. Disposition shall be a matter for agreement.

19.1 A manufacturer's certification shall be furnished to the purchaser stating that material has been manufactured, tested, and inspected in accordance with this specification, and that the test results on representative samples meet specification requirements. A report of the test results shall be furnished.

20.1 Each length of pipe shall be legibly marked with appropriate symbols by stenciling, stamping, or rolling to show the manufacturer's name, the size, the specification designation, the grade, and the hydrostatic test pressure when tested, or the letters "NH" when not tested.

20.2 In addition to the requirements in 20.1, bar coding is acceptable as a supplemental identification method. The purchaser may specify in the order a specific bar coding system to be used.

21.1 When specified on the purchase order, packaging, marking, and loading for shipment shall be in accordance with Practices A700.

21.2 The applicable levels shall be as specified in the contract. Marking for shipment of such material shall be in accordance with Fed. Std. No. 123 for civil agencies and MIL-STD-129 or Fed. Std. No. 183 if continuous marking is required for military agencies.

X1.1 Additional data on dimensions nominal weights (masses) and test pressures is provided in Table X1.1.

X1.2 Additional data on wall thicknesses are provided in Table X1.2.