API Spec 5ST-2010 pdf download.Specification for Coiled Tubing U.S. Customary and SI Units.
6.2.4 Flattening Test All coiled tubing products that are produced to this specification shall comply with the flattening requirements shown in Table A.4. The acceptance criteria for flattening tests are as follows. No cracks or breaks exceeding 0.125 in. (3.2 mm) in any direction in the weld or the parent metal shall occur on the outside surface until the distance between the plates is less than the value calculated by the equations given in Table 4. Cracks that originate at the edge of the specimen and are less than 0.25 in. (6.4 mm) long shall not be cause for rejection. The minimum test frequency for milled lengths of coiled tubing shall be at least one flattening test from each end of each continuously milled length. 6.2.5 Flaring Test All grades of coiled tubing shall be subjected to a flaring test as specified in 8.3.3. The acceptable criterion is no cracking in the weld seam region or base metal up to a minimum ID expansion of ID f (defined in 8.3.3). 6.2.6 Fracture Toughness Test Fracture toughness testing for Charpy V-Notch energy is required where requested on the purchase order, considering the limitations imposed by diameter and thickness of the tubing ordered. Full size transverse (to the tube direction) specimens should be used when possible based upon pipe geometry per ASTM A370. When full size transverse specimens are not possible, the largest sub size specimens shall be used ( 3 / 4 , 1 / 2 ). When transverse specimens are not possible, 1 / 2 size longitudinal specimens shall be used. The test specimens shall be oriented circumferentially from a location 90° from the weld with the axis of the notch oriented through the pipe wall. All tests shall be conducted at 32 °F (0 °C). The minimum absorbed energy requirements for full size specimens shall be 20 ft-lb (27 J) average, 15 ft-lb (20 J) minimum individual for full size transverse specimens, 30 ft-lb (41 J) average, 20 ft-lb (27 J) minimum individual for full size longitudinal specimens.
7.2 Length of Strings and Sections of Strings 7.2.1 General The minimum and maximum length of the tubing shall be specified on the purchase agreement. The accuracy of length measuring devices shall be equal to or less than 1 %. 7.2.2 Coiled Tubing String Length Profile The preliminary length profile of a tapered coiled tubing string shall be specified by the purchaser following established criteria for the proposed service, and attached to the purchase agreement form. The final coiled tubing string length profile shall be by agreement between the purchaser and the manufacturer. 7.3 Diameter 7.3.1 Outside Diameter The outside diameter shall be within the tolerances shown in Table A.7 for product in the as-milled condition. Diameter measurements of coiled tubing shall be made with a caliper that measures actual diameter across a single plane, with the diameter of record representing the average of the maximum and minimum diameter readings. Diameter measurements shall be made on both ends of each spooled length of coiled tubing on segments that have not been subjected to plastic deformation from spooling. 7.3.2 Ovality When agreed upon between the manufacturer and the purchaser the ovality of the tubing shall be measured within 150 ft (45.7 m) of the ends, as installed on the reel. Ovality is defined as 2(D max – D min )/(D max + D min ) where D max and D min are the measured diameters at a specific location along the tubing, and may be expressed as a percentage.
7.6 Tube-to-tube Welds By written agreement, and when specified on the purchase agreement, two or more lengths of the same grade of tubing may be welded together by the manufacturer. See Annex B. 7.7 Workmanship and Defects 7.7.1 General Imperfections of the types described in 7.7.2 to 7.7.12 that exceed the specified criteria shall be considered defects. 7.7.2 Dents The tubing shall contain no dents. 7.7.3 Offset Skelp Edges The radial offset of the skelp edges of the longitudinal weld shall not exceed 0.01 0 in. (0.3 mm) or 0.05t, whichever is greater. 7.7.4 Height of Outside Seam Weld Flash The outside seam weld flash shall be trimmed to be flush with the tube outer surface. 7.7.5 Height of Inside Seam Weld Flash Column 18.104.22.168 Flash Height The inside seam weld of “flash-in” tubing shall not extend above the prolongation of the original inside surface of the tubing more than 0.090 in. (2.3 mm), or the specified wall thickness, t, whichever is less.