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.
3.3 Plugs Pressure retaining plugs shall conform to ASME B16.11, unless otherwise agreed between pur- chaser and manufacturer. Plug material shall be at least as corrosion resistant as the corresponding flange material. 4 SIZE Orifice flange sizes are indicated by the nominal pipe size to which they are attached. Only those listed in Tables 1 through 5; Tables I-1 through I-5, and Mandatory Appendix II are considered standard. 5 MARKING Flanges shall be marked as required in ASME B16.5. For welding neck flanges only, the bore diameter shall be marked. 6 FLANGE FACING FINISH The finishofcontactfaces shallconform to the require- ments of ASME B16.5. 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.
9 JACK SCREW PROVISION 9.1 Location Each flange shall have a machine bolt mounted in a hole drilled on the flange bolt circle center line at 90 deg from the pressure taps, for use as a jack screw. Machine bolt shall be regular with one heavy hex nut. See Fig. 3. 9.2 Slot for Nut A slot shall be provided in the flange 2 mm (0.06 in.) wider than the width across flats ofthe nut. The depth of the slotshall admitthe nutso thatthere is no interference with the joining of the flanges when bolted together without orifice plate. 9.3 Tapped Hole As an alternative to para. 9.2, a tapped hole may be provided and the hex nut omitted when agreed on between the purchaser and the manufacturer. 10 FLANGE DIMENSIONS Dimensions are listed in Tables 1, 2, 3, 4, and 5, for metric, and Tables I-1, I-2, I-3, I-4, and I-5, and Mandatory Appendix II for U.S. Customary. 11 FLANGE THREADS Threaded flanges shall have an American National Standard taper pipe thread conforming to ASME B1.20.1. (a) The thread shall be concentric with the axis of the flange. Variations inalignmentshall notexceed 5 mm/M (0.06 in./ft).