ASTM A106 Pipe Specifications

ASTM A106 Hot-finished pipe need not be heat treated. Cold-drawn pipe shall be heat treated after the final cold draw pass at a temperature of 1200°F (650°C) or higher.

An analysis of each heat of steel shall be made by the steel manufacturer to determine the percentages of the elements specified. If the secondary melting processes are employed, the heat analysis shall be obtained from one remelted ingot or the product of one remelted ingot of each primary melt. The chemical composition thus deter- mined, or that determined from a product analysis made by the manufacturer, if the latter has not manufactured the steel, shall be reported to the purchaser or the purchaser-s representative, and shall conform to the requirements specified.

ASTM A106 pipe shall conform to the requirements as to chemical composition prescribed.

For pipe NPS 2 [DN 50] and under, a sufficient length of pipe shall stand being bent cold through 90° around a cylindrical mandrel, the diameter of which is twelve times the outside diameter (as shown in ASME B 36.10M) of the pipe, without developing cracks. When ordered for close coiling, the pipe shall stand being bent cold through 180° around a cylindrical mandrel, the diameter of which is eight times the outside diameter (as shown in ASME B 36.10M) of the pipe, without failure.

Subject to the approval of the purchaser, for pipe whose diameter exceeds 10 in. [250 mm], it shall be permissible for the bend test to be substituted for the flattening test described in Section 12. The bend test specimens shall be bent at room temperature through 180° with the inside diameter of the bend being 1 in. [25 mm], without cracking on the outside portion of the bent portion.

For pipe whose diameter exceeds 25 in. [635 mm] and whose diameter to wall thickness ratio is 7.0 or less, the bend test described shall be conducted instead of the flattening test.

Except as allowed by 11.2, for ASTM A106 pipe over NPS 2 [DN50], a section of pipe not less than 21-2 in. [63.5 mm] in length shall be flattened cold between parallel plates until the opposite walls of the pipe meet. Flattening tests shall be in accordance with Specification A 530/A 530M, except that in the formula used to calculate the -H- value, the following -e- constants shall be used:

0.08 for Grade A

0.07 for Grades B and C

When low D-to-t ratio tubulars are tested, because the strain imposed due to geometry is unreasonably high on the inside surface at the six and twelve o-clock locations, cracks at these locations shall not be cause for rejection if the D-to-t ratio is less than ten.

As an alternative to the hydrostatic test at the option of the manufacturer or where specified in the purchase order as an alternative or addition to the hydrostatic test, the full body of each ASTM A106 pipe shall be tested with a nondestructive electric test in accordance with Practice E 213, E 309, or E 570. In such cases, the marking of each length of pipe so furnished shall include the letters -NDE.- It is the intent of this nondestructive electric test to reject pipe with imperfections that produce test signals equal to or greater than that produced by the applicable calibration standard.

Where the nondestructive electric test is performed, the lengths shall be marked with the letters -NDE.- The certification, where required, shall state -Nondestructive Electric Tested- and shall indicate which of the tests was applied. Also, the letters -NDE- shall be appended to the product specification number and material grade shown on the certification. The following information is for the benefit of the user of this specification:

The reference standards defined are convenient standards for calibration of nondestructive testing equipment. The dimensions of such standards are not to be construed as the minimum sizes of imperfections detectable by such equipment.

The ultrasonic testing referred to in this specification is capable of detecting the presence and location of significant longitudinally or circumferentially oriented imperfections: however, different techniques need to be employed for the detection of such differently oriented imperfections. Ultrasonic testing is not necessarily capable of detecting short, deep imperfections.

The eddy current examination referenced in this specification has the capability of detecting significant imperfections, especially of the short abrupt type.

The flux leakage examination referred to in this specification is capable of detecting the presence and location of significant longitudinally or transversely oriented imperfections: however, different techniques need to be employed for the detection of such differently oriented imperfections.

The hydrostatic test has the capability of finding defects 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. Hydrostatic testing is not necessarily capable of detecting very tight, through-the-wall imperfections or imperfections that extend an appreciable distance into the wall without complete penetration.

A purchaser interested in ascertaining the nature (type, size, location, and orientation) of discontinuities that can be detected in the specific applications of these examinations is directed to discuss this with the manufacturer of the tubular product.

For ultrasonic testing, the calibration reference notches shall be, at the option of the producer, any one of the three common notch shapes shown in Practice E 213. The depth of notch shall not exceed 121-2 % of the specified wall thickness of the pipe or 0.004 in. [0.1 mm], whichever is greater.

For eddy current testing, the calibration pipe shall contain, at the option of the producer, any one of the following discontinuities to establish a minimum sensitivity level for rejection.

Nipples shall be cut from ASTM A106 pipe of the same dimensions and quality described in the specification.

The tensile requirements specified shall be determined on one length of pipe from each lot (Note 3) of 400 lengths or fraction thereof of each size under NPS 6 [DN 150], and from each lot of 200 lengths or fraction thereof of each size NPS 6 [DN 150] and over as per ASTM A106.

The flattening test specified in Section 12 shall be made on one length of pipe from each lot of 400 lengths or fraction thereof of each size over NPS 2 [DN 50], up to but not including NPS 6 [DN 150], and from each lot of 200 lengths or fraction thereof, of each size NPS 6 [DN 150] and over.

If any test specimen shows flaws or defective machining, it shall be permissible to discard it and substitute another test specimen.

If the percentage of elongation of any tension test specimen is less than that as prescribed and any part of the fracture is more than 3-4 in. [19 mm] from the centre of the gage length of a 2-in. [50-mm] specimen as indicated by scribe scratches marked on the specimen before testing, a retest shall be allowed. If a specimen breaks in an inside or outside surface flaw, a retest shall be allowed.

Should a crop end of a finished pipe fail in the flattening test, one retest is permitted to be made from the failed end. Pipe shall be normalized either before or after the first test, but pipe shall be subjected to only two normalizing treatments.

On NPS 8 [DN 200] and larger, specimens cut either longitudinally or transversely shall be acceptable for the tension test. On sizes smaller than NPS 8 [DN 200], the longitudinal test only shall be used.

When round tension test specimens are used for pipe wall thicknesses over 1.0 in. [25.4 mm], the mid-length of the longitudinal axis of such test specimens shall be from a location midway between the inside and outside surfaces of the pipe.

Test specimens for the bend test specified and for the flattening tests shall consist of sections cut from a pipe. Specimens for flattening tests shall be smooth on the ends and free from burrs, except when made on crop ends.

For ASTM A106 pipe When test reports are requested, in addition to the requirements of Specification A 530/A 530M, the producer or supplier shall furnish to the purchaser a chemical analysis report for the elements specified.

In addition to the marking prescribed in Specification A 530/A 530M, the marking on ASTM A106 pipe shall include heat number, the information, an additional symbol -S- if one or more of the supplementary requirements apply; the length, OD 1 %, if ordered as special outside diameter tolerance pipe; ID 1 %, if ordered as special inside diameter tolerance pipe; the schedule number, weight class, or nominal wall thickness; and, for sizes larger than NPS 4 [DN 100], the weight. Length shall be marked in feet and tenths of a foot [metres to two decimal places], depending on the units to which the material was ordered, or other marking subject to agreement. For sizes NPS11-2, 11-4, 1, and 3-4 [DN 40, 32, 25, and 20], each length shall be marked as prescribed in Specification A 530/A 530M. These sizes shall be bundled in accordance with standard mill practice and the total bundle footage marked on the bundle tag; individual lengths of pipe need not be marked with footage. For sizes less than NPS 3-4 [DN 20], all the required markings shall be on the bundle tag or on each length of pipe and shall include the total footage; individual lengths of pipe need not be marked with footage. If not marked on the bundle tag, all required marking shall be on each length.

When ASTM A106 pipe sections are cut into shorter lengths by a subsequent processor for resale as material, the processor shall transfer complete identifying information, including the name or brand of the manufacturer to each unmarked cut length, or to metal tags securely attached to bundles of unmarked small diameter pipe. The same material designation shall be included with the information transferred, and the processor-s name, trademark, or brand shall be added.

Bar Coding-Bar coding is acceptable as a supplementary identification method. The purchaser may specify in the order a specific bar coding system to be used.

The flattening test of Specification A 530/A 530M shall be made on a specimen from one end or both ends of each pipe. Crop ends may be used. If this supplementary requirement is specified, the number of tests per pipe shall also be specified. If a specimen from any length fails because of lack of ductility prior to satisfactory completion of the first step of the flattening test requirement, that ASTM A106 pipe shall be rejected subject to retreatment in accordance with Specification A 530/ A 530M and satisfactory retest. If a specimen from any length of pipe fails because of a lack of soundness, that length shall be rejected, unless subsequent retesting indicates that the remaining length is sound.

The steel shall be homogeneous as shown by etching tests conducted in accordance with the appropriate sections of Method E 381. Etching tests shall be made on a cross section from one end or both ends of each pipe and shall show sound and reasonably uniform material free from injurious laminations, cracks, and similar objectionable defects. If this supplementary requirement is specified, the number of tests per pipe required shall also be specified. If a specimen from any length shows objectionable defects, the length shall be rejected, subject to removal of the defective end and subsequent retests indicating the remainder of the length to be sound and reasonably uniform material.

At the request of the purchaser, one tensile test shall be performed by the manufacturer on a test specimen from each heat of steel furnished which has been either stress relieved at 1250°F or normalized at 1650°F, as specified by the purchaser. Other stress relief or annealing temperatures, as appropriate to the analysis, may be specified by agreement between the purchaser and the manufacturer.

The internal surface of hot finished ferrite steel pipe and tube shall be manufactured to a free of scale condition equivalent to the visual standard listed in SSPC-SP6. Cleaning shall be performed in accordance with a written procedure that has been shown to be effective.

The steel shall be killed steel, with the primary melting process being open-hearth, basic-oxygen, or electric-furnace, possibly combined with separate degassing or refining. If secondary melting, using electro slag remelting or vacuum-arc remelting is subsequently employed, the heat shall be defined as all of the ingots remelted from a single primary heat.

Steel cast in ingots or strand cast is permissible. 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.

For pipe NPS 11-2 [DN 40] and under, it shall be permissible to furnish hot finished or cold drawn.

Unless otherwise specified, pipe NPS 2 [DN 50] and over shall be furnished hot finished. When agreed upon between the manufacturer and the purchaser, it is permissible to furnish cold-drawn pipe.

Dimensions, Mass, and Permissible Variations

Mass-The mass of any length of pipe shall not vary more than 10 % over and 3.5 % under that specified. Unless otherwise agreed upon between the manufacturer and the purchaser, pipe in NPS 4 [DN 100] and smaller may be weighed in convenient lots; pipe larger than NPS 4 [DN 100] shall be weighed separately.

Diameter-The tolerances for diameter shall be in accordance with the following:

Except for pipe ordered as special outside diameter tolerance pipe or as inside diameter tolerance pipe, variations in outside diameter shall not exceed those prescribed in Table 3.

For pipe over 10 in. [250 mm] OD ordered as special outside diameter tolerance pipe, the outside diameter shall not vary more than 1 % over or 1 % under the specified outside diameter.

For pipe over 10 in. [250 mm] ID ordered as inside diameter tolerance pipe, the inside diameter shall not vary more than 1 % over or 1 % under the specified inside diameter.

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

Pipe lengths shall be in accordance with the following regular practice:

The lengths required shall be specified in the order, and No jointers are permitted unless otherwise specified.

If definite lengths are not required, pipe may be ordered in single random lengths of 16 to 22 ft [5 to 6.7 m] with 5 % 12 to 16 ft [3.7 to 4.8 m], or in double random lengths with a minimum average of 35 ft [10.7 m] and a minimum length of 22 ft [6.7 m] with 5 % 16 to 22 ft [5 to 6.7 m].

The pipe manufacturer shall explore a sufficient number of visual surface imperfections to provide reasonable assurance that they have been properly evaluated with respect to depth. Exploration of all surface imperfections is not required but consideration should be given to the necessity of exploring all surface imperfections.

Surface imperfections that penetrate more than 121-2 % of the nominal wall thickness or encroach on the minimum wall thickness shall be considered defects. Pipe with such defects shall be given one of the following dispositions:

The defect shall be removed by grinding, provided that the remaining wall thickness is within the limits specified in 16.3.

Repaired in accordance with the repair welding provisions of 18.6.

The section of pipe containing the defect may be cut off within the limits of requirements on length. Rejected.

To provide a workmanlike finish and basis for evaluating conformance with 18.2 the pipe manufacturer shall remove by grinding the following noninjurious imperfections:

Mechanical marks, abrasions and pits, any of which imperfections are deeper than 1-16 in. [1.6 mm].

Visual imperfections commonly referred to as scabs, seams, laps, tears, or slivers found by exploration in accordance to be deeper than 5 % of the nominal wall thickness.

At the purchaser-s discretion, pipe shall be subjected to rejection if surface imperfections acceptable are not scattered, but appear over a large area in excess of what is considered a workmanlike finish. Disposition of such pipe shall be a matter of agreement between the manufacturer and the purchaser.

When imperfections or defects are removed by grind- ing, a smooth curved surface shall be maintained, and the wall thickness shall not be decreased below that permitted by this specification. The outside diameter at the point of grinding is permitted to be reduced by the amount so removed.

Wall thickness measurements shall be made with a mechanical caliper or with a properly calibrated nondestructive testing device of appropriate accuracy. In case of dispute, the measurement determined by use of the mechanical caliper shall govern.

Weld repair shall be permitted only subject to the approval of the purchaser and in accordance with Specification A 530/A 530M.