ASME B16.36 pdf download Orifice Flanges
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. For ring joint flanges listed in Tables 2 through 5, Tables I-1 through I-5, and Mandatory Appendix II where radial taps will interfere with the ring groove, angular meter taps, as illustrated in Fig. 2, will be required. Each pressure tap hole shall be equipped with a pipe plug.
8.2.1 Measurement. The 24 mm(0.94 in.) dimension for raised face and 19 mm (0.75 in.) for ring joint shall be measured at the bore.
8.2.2 Identification. For ring joint flanges requiring alteration of pressure tap location due to interference with the ring groove other than methods provided in this Standard, such alteration shall be identified per agreement between purchaser and manufacturer.
8.3 Pipe Connection Unless otherwise specified, pressure tap holes may be either tapped 1 ⁄ 2 NPT in accordance with ASME B1.20.1 or 1 ⁄ 2 NPS socket connection in accordance with ASME B16.11.
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.