ASME B16.49-2017 pdf – Factory-Made, WroughtSteel, Buttwelding Induction Bends for Transportation and Distribution Systems.
11.1.2 Fracture Toughness Testing. A set of three transverse Charpy V-notch impact specimens shall be taken from the tangent, the transition zones, and the bend at both the intrados and extrados for each lot of material. See FIgure 2 or Figure 3 for locations. If the tangents and/or transition zones are not left integral to the bend, no impact tests are required except on the bend. See Figure 2 or Figure 3.
U.L3 WeLd Testing
(a) Longltudénal Seams. The tensile, Impact, and hardness tests shall be performed on the pipe or cylinder longitudinal seam weld at the locations shown in Figure 2. Acceptance criteria shall be as specified in paras. 8.1, 82, 83. and 111.4.
(b) Heitcal Seam. The tensile, impact, and hardness tests shall be performed on the pipe or cylinder helical seam at the locations shown in Figure 3. Acceptance criteria shall be as specified in paras. 8.1. 8.2, 8.3. and
11.14 Hardness Testing. The bend shall be tested for average hardness in all the same locations as the tensile tests are taken as well as each transition zone. In addition. an average hardness reading shall be taken from a minimum of two locations in the bend at the extrados and intrados. The allowable difference between the minimum and maximum hardness readings fora quadrant around the circumference Is 30 Hrinell hardness number, or equivalent. if another testing method is used. Sec Figure 2 or FIgure 3.
11.2 Production Bend Requirements
To demonstrate unilurmiry between the qualification and production bends, each production bend shall be hardness tested in all the same locations as the qualification bend. In addition, hardness readings shall be taken for each additional 30 deg of arc beyond the qualitication bend angle. All values within like quadrants around the circumference shall be within the same range as determined in para. 11.1.4. No readings shall exceed the maximum specified in Table 1. and no average shall equate to a tensile strength less than the minimum required in Tablc 1 for thc specified grade.
11.3 Testing ResuLts
The bend shall be marked with the appropriate grade symbol of Table 1 based on the test results for all locations meeting the minimum values specified for that grade. If the bend strength is different from the mating pipe, and the substitution wall thirdness for yield strength is used In accordance with para. 8.1, both the bend grade and the intended mating pipe grade shall be marked on the bend (i.e. P414/X423).
The dimensional requirements in section 12 shall be met on each bend.
12.1 OvaLity
Ovality shall be measured throughout the bend and tangents. The difference between the maximum and minimum outside diameter shall not exceed 3% of the nominal mating pipe outside diameter within the bend and 1% at the welding end, The purchaser and manufacturer may agree to a different ovality tolerance (see para.
12.2 Outside Diameter
The outside diameter of each welding end shall be wIthin 1% of the nominal mating pipe outside diameter. The diameter throughout the bend and the remainder of the tangents need only meet the ovality tolerance, unless the purchaser and manufacturer agree to other tolerances.
12.3 WaLL Thickness
The wall thickness shall be checked in sufficient locations throughout the bend to ensure that the minimum wall does not fall below 90% of the nominal mating wall thickness marked on the bend (or below the purchaser-specified minimum wall thickness). This below-tolerance allowance does not apply to those areas determined to need reinforcement as a result of design requirements ol para. 2.2. Inspection shall be done using compression wave ultrasonic examination by calibrated equipment that meets a procedure developed by the manufacturer to ensure accurate readings.
12.4 InsIde Diameter
12.4.1 Wetding Ends. For NI’S 36 (DN 900) and smaller, the inside diameter tolerance at the bevel Face shall be i2.5 mm (±0.10 in.). For larger sizes, the inside diameter tolerance shall be ±3 mm (±0.12 In.).
12.4.2 Body. Unless otherwise agreed to by the purchaser, the average Internal diameter at any location in the bend shall not be less than 97% of the minimum specified mating pipe internal diameter. Proof of conformance to this requirement shall be demonstrated by passing a sphere or other suitable gaging device through the bend without assistance of power equipment.