ASME B16.5-2020 pdf download

ASME B16.5-2020 pdf download.Pipe Flanges and Flanged Fittings.
This Standard states values in both SI (Metric) and U.S. Customary units. As an exception, diameter of bolts and flange bolt holes are expressed in inch units only. These systems of units are to be regarded separately as standard. Within the text, the U.S. Customary units are shown in parentheses or in separate tables following the SI tables. 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. Except for diameter of bolts and flange bolt holes, combining values from the two systems constitutes nonconformance with the Standard. Nonmandatory Appendix F describes how the values expressed in SI units were established. 1.7 Selection of Materials Criteria for selection of materials suitable for particular fluid service are not within the scope of this Standard. 1.8 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 observedASME issues Cases that are applicable to this Standard by, e.g., adding new materials or alternative construction requirements. The Cases (a) modify the requirements of this Standard. (b) are applicable from their issue dates until the Cases are annulled. (c) may be used only when agreed to by the purchaser and the manufacturer, and when a Case has been so agreed to, the marking on the flange shall include the Case number. 2 PRESSURE–TEMPERATURE RATINGS 2.1 General Pressure–temperature ratings are maximum allowable working gage pressures in bar units at the temperatures in degrees Celsius shown in Tables 2-1.1 through 2-3.19 for the applicable material and class designation. Tables 2-1.1C through 2-3.19C list pressure –temperature ratings using psi units for pressure at the temperature in degrees Fahrenheit. For intermediate temperatures,2.8.1 Hub Dimensions. Straight hub welding flanges have hubs of uniform thickness (see Figure 4).
Materials required for flanges and flanged fittings are listed in Table 1.1-1 with the following restrictions: (1) Plate and flat bar materials may be used only for blind flanges and reducing flanges without hubs. (2) Flanges and flanged fittings shall be manufac- tured as one piece in accordance with the applicable mate- rial specification. Assembly of multiple pieces into the finished product by welding or other means is not permitted by this Standard. (b) Each forged flange shall be finished from a part that is brought as nearly as practicable to the finished shape and size by a compressive plastic hot-working operation that consolidates the material to produce an essentially wrought structure, and shall be so processed during the operation as to cause metal flow in the direction most favorable for resisting the stress encountered in service. (c) Recommended bolting materials are listed in Table 1.1-2 (see para. 5.3). (d) Corresponding materials listed in Section II of the ASME Boiler and Pressure Vessel Code may be used provided that the requirements of the ASME specification are identical to or more stringent than the ASTM speci- fication for the Grade, Class, or type of material. 5.1.1 Application. Criteria for the selection of materials are not within the scope of this Standard. The possibility of material deterioration in service should be considered by the user. Carbide phase conversion to graphite and exces- sive oxidation of ferritic materials, susceptibility to inter- granular corrosion of austenitic materials, or grain boundary attack of nickel base alloys are among those items requiring attention. Except as described in paras. 2.8.2 through 2.8.4, the straight hub welding flanges shall have dimensions and tolerances of the welding neck flanges of the same size and class set forth in Tables 8, 11, 14, 16, 18, 20, and 22 (Tables 8C, 11C, 14C, 16C, 18C, 20C, and 22C). In Figure 4 the tolerances described in section 7 are applicable. 2.8.2 Length Through Hub. The length through hub shall be 229 mm (9 in.) for NPS 4 and smaller and 305 mm (12 in.) for larger than NPS 4. Other lengths may be furnished by agreement between the end user and manufacturer. 2.8.3 Bore. The bore diameter B shall be equal to the B ð20Þ dimension of the welding neck flange. Other bores may be furnished by agreement between the end user and manu- facturer. In no case shall the bore diameter exceed the bore of the same size and class lapped flange. 2.8.4 Hub End. The standard flange shall be provided with square cut end. The end user may specify welding end preparation in accordance with para. 6.7.