ASME B16.50:2018 pdf free download – Wrought Copper and Copper Alloy Braze-Joint Pressure Fittings
2.1 Relevant Units
This Standard states values in both SI (metric) and U.S. Customary units. These systems of units are to be regarded separately as standard. Within the text, the U.S. Customary units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, it is required that each system of units be used independently of the other. Combining values from the two systems constitutes nonconformance with the Standard.
2.2 References
Standards and specifications adopted by reference in this Standard are shown in Mandatory Appendix I, which is part of this Standard. It is not considered practical to identify the specific edition of each standard and spec- ification in the individual references. Instead, the specific edition reference is identified in Mandatory Appendix I.
3.1 Rating of System
The internal pressure–temperature rating for a braze joint system is dependent on 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 3.1-1, made with typical commercial brazing materials, shall be considered equal to the values given in Table 3.1-2. The internal pressure–temperature rating of the system shall be the lowest of the values shown in Table 3.1-2 and those of the tube, valves, or appurtenances.
3.2 Fitting Bursting Strength
Fittings manufactured to this Standard shall have an ambient-temperature bursting strength of at least 4 times the 38°C (100°F) internal pressure rating as shown in Table 3.1-2.
4.1 Size
The size of the fittings shown in Table 3.1-1 corresponds to standard water tube size as shown in ASTM B88. 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 Figure 4.1-1.
7 LAYING LENGTHS
Due to widely varying manufacturing processes, mean- ingful laying length requirements of fittings cannot be established. Consult the manufacturer for these dimensions.
8 TUBE STOPS
Except for repair couplings, fittings shall be manufac- tured with a tube stop. Repair couplings shall not require a tube stop. The tube stop shall control joint length, even with an external (FTG) end having the minimum outside diameter shown in Table 3.1-1. Examples of various tube stop configurations are shown in Figure 8-1.
9 INSPECTION TOLERANCE
9.1 Convention
For determining conformance with this Standard, the convention for fixing significant digits where limits (maximum and minimum values) are specified shall be as defined in ASTM E29. This requires that an observed or calculated value be rounded off to the nearest unit in the last right-hand digit used for expressing the limit. Decimal values and tolerances do not imply a particular method of measurement.
10.1 Countersink or Chamfer
All internal threads shall be countersunk a distance no less than one-half the pitch of the thread, at an angle of approximately 45 deg with the axis of the thread. All external threads shall be chamfered at an angle of 30 deg to 45 deg from the axis. Countersinking and cham- fering shall be concentric with the threads. The length of threads shall be measured to include the countersink or chamfer.