ASME B16.36:2006 pdf download

ASME B16.36:2006 pdf download.Orifice Flanges
1 SCOPE
1.1 General This Standard covers flanges (similar to those covered in ASME B16.5) that have orifice pressure differential connections. Coverage is limited to the following: (a) welding neck flanges Classes 300, 600, 900, 1500, and 2500. U.S. Customary units are presented in Mandatory Appendix I. (b) slip-on and threaded Class 300. (c) welding neck flanges Class 400 in U.S. Customary units in Mandatory Appendix II. 1.2 References Codes, standards, and specifications containingprovi- sions to the extent referenced herein constitute require- ments of this Standard. These reference documents are listed in Mandatory Appendix III. 1.3 Quality Systems Nonmandatory requirements relating to the product manufacturer’s Quality System Program are described in Nonmandatory Appendix A. 1.4 Relevant Units This Standard states values in both 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 stan- dard. Within the text, the U.S. Customary units are shown in parentheses or in separate tables. The values stated in each system are not exact equivalents; there- fore, 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. Except for Class 400 the values in U.S. Customary units are in Mandatory Appendix I. The main text of this Standard does not contain requirements for Class 400 welding neck flange; however, Mandatory Appendix II does contain requirements for this class, expressed in U.S. Customary units only.1.5 Convention For the purposes of determining conformance with this Standard, the convention for fixing significant digits where limits and maximum and minimum values are specified, shall be rounded as defined in ASTM Practice 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 tolerances do not imply a particular method of mea- surements. 1.6 Denotation 1.6.1 Pressure Rating Designation (a) Class, followed by a dimensionless number, is the designationforpressure–temperature ratings as follows: Classes 300 600 900 1500 2500. (b) Class 400 is retained in the U.S. Customary tables. 1.6.2 Sizes. NPS, followed by a dimensionless number, is the designation for the nominal flange size. NPS is related to the reference nominal diameter, DN, used ininternational standards. The relationship is, typi- cally, as follows
7 GASKETS FOR RAISED FACE FLANGES
7.1 Gasket Thickness Flange dimensions are based on the use of 1.5 mm (0.06 in.) thick gaskets. 7.2 Flange Gaskets Requiring Dimensional Changes When the location of the pressure tap with respect to the orifice plate is critical to the service and metering conditions, its location may be altered to accommodate other than 1.5 mm (0.06 in.) thick gaskets or ring type joint gaskets whose thickness may vary from that listed in in Tables 2, 3, 4, and 5 or those listed in Tables I-2, I-3, I-4, and I-5 or Mandatory Appendix II. The alteration of location may also be accomplished by the removal of 2 mm (0.06 in.) from the raised face of the flange. If an original 2 mm (0.06 in.) high raised face is removed, the user is cautioned to limitthe outside diameter of the gasket or orifice plate to the tabulated R dimension.
8 PRESSURE TAPS
8.1 General Each orifice flange shall be provided with two pres- sure tap holes extending radially from the outside diam- eter of the flange to the inside diameter of the flange. Corner taps may be used on NPS 1 1 ⁄ 2 and smaller if space permits. See Fig. 1. For ring joint flanges listed in Tables 2 through 5, Tables I-1 through I-5, and Mandatory Appendix II