ASME B16.49-2007 pdf – Factory-Made,Wrought Steel, Buttwelding Induction Bends for Transportation and Distribution Systems.
11.1 Qualification Bend Requirements
11.1.1 Tens4le Testing. Transverse tensile samples for NI’S S (DN 2(X)) or brger shall be taken from the tangent, the transition zone, and the bend segment at both the intrados and extrados for each lot of material as shown in Fig. 2 or 3. For sizes smaller than NI’S S (DN 2(X)), either transverse or longitudinal test specimens shall be used. If the tangents and/or transition zones are not left integral to the bend, no tensile tests are required except on the bend. See Fig 2 or 3.
11.12 Fracture Toughness Testing. A set of three transverse Charpv 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 Fig. 2 or 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 Fig. 2 or 3.
11.1.3 We4d Testing
(a) Ltmgitudinal Snios. [he tensile, impact. and hardness tests shall be performed on the pipe or cylinder longitudinal seam weld at the locations shown in Fig. 2. Acceptance criteria shall be as specified in paras. 5.1. 8.2, 8.3, and 11.1.4.
(b) Helical Seam, The tensile, impact, and hardness tests shall be performed on the pipe or cylinder helical scam at the locations shown in Fig. 3. Acceptance criteria shall he as specified in paras. 8.1, 8.2, 83, and 11.1.4.
11.1.4 Hardness Testing. The bend shall be tested fur 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 for a quadrant around the circumference is 30 Hrinell hardness number, or equivalent, if another testing method is used. Sec Fig. 2 or 3.
11.2 Production Bend Requirements
To demonstrate uniformity between the qualification and pn.iduction bends, each production bend shall be hardness tested in all the same locations as the qualification bend. In addition, hardness readings shall be taken fur each additional 3odeg of arcbeyond the qualification bend angle. All values within like quadrants around the circumference shall be within the same range as determined in pars. 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 Table I for the specified grade.
11.3 Testing Results
The bend shall be marked with the appropriate grade symbol of Table I 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 of wall thkkiwss For yield strength is used in accordance with para. tl.1, both the bend grade and the intended mating pipe grade shall be marked on the bend (i.e., P414/X483).
12 DIMENSIONAL REQUIREMENTS
The dimensional requirements in section 12 shall be met on each bend.
12.1 OvaLity
Ovalitv shall be measured throughout th bend and tangents. The difference between the maximum and minimum outside diameter shall not esceed 3% of the nominal mating pipe outside diameter within the bend and 1% at the welding end. The purchaser and manufac hirer may agree to a different ovallty tolerance (see para.
SRI5.3).
12.2 Outside Diameter
The outside diameter of each welding end shall be within %of the nominal mating pipe outside diameter. The diameter throughout the bend and the remainder oF 11w tangent. need only meet 11w ovality tolerance, unless the purchaser and manulachirer 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 th 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 of para. 22 Inspection shall be done using compression wave ultrasonic examination by calibrated equipment that meets a procedure developed by the manufacturer to ensure accurate readings.