ASME B16.50 pdf download WROUGHT COPPER AND COPPER ALLOY BRAZE-JOINT PRESSURE FITTINGS
1.1 General This Standard establishes requirements for wrought copper and wrought copper alloy braze-joint seamless fittings designed for use with seamless copper tube conforming to ASTM Standard Specification, B 88 (Water and General Plumbing Systems), B 280 (Air Conditioning and Refrigeration Service), and B 819 (Medical Gas Systems). This Standard covers joints assembled with brazing materials conforming to ANSI/AWS A5.8. This Standard is allied to ASME standards B16.18 and B16.22. It provides requirements for fitting-ends suitable for brazing. This Standard covers:
(a) pressure-temperature ratings;
(b) abbreviations for end connections;
(c) size and method of designating openings of fit- tings;
(f) dimensions and tolerances; and
1.2 Convention For the purpose of determining conformance with this Standard, the convention for fixing significant digits where limits, maximum or minimum values, are speci- fied shall be “rounding off” as defined in ASTM E 29. This requires that an observed or calculated value shall be rounded off to the nearest unit in the last right-hand digit used for expressing the limit.
1.3 Units of Measure The values stated in either SI (metric) or US Custom- ary (in.-lb) units of measure shall be regarded separately as standard. Within the main text, SI units are given. For convenience, the customary units are shown in Mandatory Appendix I. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. 1 NOTE: Combining values from the two systems may result in nonconformance with the standard.
1.4 References Standards and specifications adopted by reference in this Standard are shown in Mandatory Appendix II, which is part of this Standard. It is not considered practical to identify the specific edition of each standard and specification in the individual references. Instead, the specific edition reference is identified in Mandatory Appendix II.
1.5 Quality Systems Requirements relating to the product manufacturer’s Quality System Programs are described in Nonmanda- tory Appendix B.
2 PRESSURE-TEMPERATURE RATINGS
2.1 Rating of System The internal working pressure-temperature rating for a braze-joint system is dependent upon, not only fitting and tube strength, but also selection of valves and appurtenances. Pressure-temperature ratings for fittings and braze joints to the dimensions of Table 3 (Table I3), made with typical commercial brazing materials, shall be considered equal to the values given in Table 1 (Ta- ble I1). The internal working-pressure rating of the system shall be the lowest of the values shown in Table 1 (Table I1) and those of the tube, valves, or appurtenances.
2.2 Fitting Bursting Strength Fittings manufactured to this Standard shall have an ambient-temperature bursting-strength of at least four times the 38°C (100°F) rated internal working-pressure as shown in Table 1 (Table I1).
3.1 Abbreviations The following symbols are used to designate the type of fitting end: C p braze-joint fitting end made to receive cop- per tube diameter (female) F p internal ANSI standard taper pipe-thread end (female) NPTI M p external ANSI standard taper pipe-thread end (male) NPTE FTG p braze-joint fitting end made to copper tube diameter (male)
3.2 Definitions out-of-roundness: the maximum measured diameter minus minimum measured diameter. ovality: the elliptical condition associated with out- of-roundness.
4 SIZE The size of the fittings shown in Table 3 and Table I3 corresponds to standard water tube size as shown in ASTM B 88, Specification for Seamless Copper Water Tube. The size of the threaded ends corresponds to nominal pipe size as shown in ASME B1.20.1. Fittings are designated by the size of the openings in the sequence illustrated in Fig. 1.
5 MARKING Each fitting shall be permanently marked with the manufacturer’s name or trademark in accordance with MSS SP-25 and the letters “BZ” in upper case. Marking on fittings less than size 1 ⁄ 2 or on any fitting where it damages the brazing surfaces is not required.
6 MATERIAL (a) Fittings shall be made from copper UNS Nos.