ASME B16.9-2007 pdf – Factory-Made Wrought Buttwelding Fittings.
The arc or radius may be terminated in tangents. Except as provided for block forgings (see section 5), the projected profile of external surfaces of fittings shall not have sharp intersections (corners) and/or collapsed arcs.
Unless otherwise specified, the details of the welding end preparation shall be in accordance with Table 12. Transitions from the welding bevel to the outside surface of the fitting and from the root face to the inside surface of the fitting lying within the maximum envelope shown in Fig. I are at the manufacturer’s option, except as covered in Note (5) of Fig. 1 or unless otherwise specifically ordered.
9.1 Required Tests
Proof tests shall be made as set forth in this Standard when the manufacturer chooses proof testing to qualify the fitting design. Unless otherwise agreed upon between the manufacturer and purchaser, the proof test shall be one based on the computed bursting pressure of the fitting and its connecting piping.
Lap joint stub ends are exempt from proof testing because they are used in a flange assembly, which will have different ratings depending on service application.
9.2 Test Assembly
9.2.1 Representative Components. Fittings that are representative of production and selected for testing shall be identified as to material, grade, and lot, including heat treatment. They shall be inspected for dimensional compliance to this Standard.
9.2.2 Other Components. Straight seamless or welded pipe sections whose calculated bursting strength is at least as great as the proof test pressure as calculated in para. 9.3 shall be welded to each end of the fitting to be tested. Any internal misalignment greater than 1.5 mm (0.06 in.) shall be reduced by taper boring at a slope not over 1:3. Length of pipe sections for closures shall be as follows:
(a) Minimum length of pipe shall be one pipe O.D. for NPS 14 (DN 350) and smaller.
(b) Minimum length of pipe shall be one-half pipe O.D. for NPS greater than 14 (DN 350).
9.3 Test Procedure
Test fluid shall he water or other liquid used for hydrostatic testing. Hydrostatic pressure shall be applied to the assembly. The test is successful if the fitting withstands, without rupture.
9.4 Applicability of Test Results
It is not necessary to conduct an individual test of fittings with all combinations of sizes, wall thicknesses, and materials. A successful proof test on one representative fitting may represent others to the extent described in paras. 9.4.1, 9.4.2, and 9.4.3.
9.4.2 Thickness Range. One test fitting may be used to qualify similarly proportioned fittings with LiD ranges from one-half to three times that for the tested fitting.
9.4.3 Material Grades. The pressure retaining capacity of a geometrically identical fitting made of various grades of steel will be directly proportional to the tensile properties of the various grades; see para. 2.1. Therefore, it is necessary to test only a single material grade in a representative fitting to prove the design of the fitting.
Hydrostatic testing of wrought fittings is not required by this Standard. All fittings shall be capable of withstanding, without leakage or impairment of serviceability, a hydrostatic test pressure required by the applicable piping code for seamless pipe of material equivalent to the fitting material, and of the size and wall thickness the fitting marking identifies.
Tolerances for fittings are shown in Tables 13 and 1-12, and apply to the nominal dimensions given in Tables I through 11 and Tables I-I through I-il. Where given in the tables, the minimum and maximum dimensions are based on these tolerances. The listings with decimals do not imply precision measurement, such as use of vernier, micrometer, electronic read out equipment, etc.