ASME B16.1:2010 pdf download

ASME B16.1:2010 pdf download.Gray Iron Pipe Flanges and Flanged Fittings
1 SCOPE
This Standard covers Classes 25, 125, and 250 Gray Iron Pipe Flanges and Flanged Fittings. It includes (a) pressure–temperature ratings (b) sizes and method of designating openings of reducing fittings (c) marking (d) materials (e) dimensions and tolerances (f) bolting and gaskets (g) pressure testing
2 GENERAL
2.1 References Standards and specifications adopted by reference in this Standard are shown in Mandatory Appendix II, which is part ofthis Standard. Itis notconsidered practi- cal to identify the specific edition of each referenced standard and specification in the text, when referenced. Instead, the specific editions of the referenced standards and specifications are listed in Mandatory Appendix II. 2.2 Quality Systems Requirements relating to the product manufacturer’s Quality System Programs are described in Nonmandatory Appendix A. 2.3 Relevant Units This Standard states values in both SI 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. Within thetext, theU.S. Customaryunits are showninparenthe- sis or in separate tables. The values stated in each table 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, com- bining values from the two systems constitutes noncon- formance with the standard. 2.4 Service Conditions Criteria for selection of materials suitable for particu- lar fluid service are notwithin the scope ofthis Standard.2.5 Convention For the purpose of determining conformance with this Standard, the convention for fixing significant digits where limits, maximum and minimum values are speci- fied, shall be rounded 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. Decimal values and tolerance do not imply a particular method of measurement.
3 PRESSURE–TEMPERATURE RATINGS
3.1 General Pressure–temperature ratings are maximum allow- able working pressures in bar units at the temperature in degrees Celsius shown in Table 1 for the applicable material and class designation. Table I-1 of Mandatory Appendix I lists pressure–temperature ratings using psi units for pressure at the temperature in degrees Fahrenheit. For intermediate temperatures, linear inter- polation is permitted. Interpolation between class desig- nations is not permitted.3.2 Flanged Joints A flanged joint is composed of independent interre- lated components; the flanges, the gasket, and the bolt- ing, that are assembled manually. Proper controls must be exercised in the selection and application for these elements to attain a joint that has acceptable leak tight- ness. Special techniques, such as controlled bolt tight- ening described in ASME PCC-1, may be used to achieve a tight joint in service. 3.3 Rating Temperature Temperatures shown for the corresponding pressure rating shall be the material temperature of the pressure- retaining structure. It may be assumed that the material temperature is the same as the fluid temperature. Use of a pressure rating at a material temperature other than that of the contained fluid is the responsibility of the user and subject to the requirements of any applicable code or regulation. 3.4 Low-Temperature Ratings Pressure ratings for temperatures below −29°C (−20°F) should be determined in accordance with low- temperature properties of gray iron (ASTM A 126) as governed by applicable code or regulation. 3.5 Ductility Gray Iron has little ductility, therefore, the resistance of these flanges and flanged fittings to excessive forces and suddenly applied loads is significantly less than for more ductile materials such as steel. The following precautions are recommended: (a) These flanges and flanged fittings should not be used where suddenly applied loads such as rapid pres- sure fluctuation may occur. (b) Alignment of flange faces is essential along with control of assembly bolt torque so as not to over-stress the gray iron flanges. Care should also be exercised to ensure that piping loads transmitted to gray iron flanges are controlled.