ASME B16.36:2020 pdf free download – Orifice Flanges
1 SCOPE
This Standard covers pressure-temperature ratings,materials, dimensions, tolerances, testing, and making of 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 300,400,600,90o,150o,and 2500
b) slip-on and threaded Class 3002 GENERAL
2.1 References
Codes,standards, and specifications containing provi-sions to the extent referenced herein constitute require-ments of this Standard.These reference documents arelisted in Mandatory Appendix l1.
2.2 Quality Systems
Nonmandatory requirements relating to the productmanufacturer’s Quality System Program are describedin Nonmandatory Appendix A.
2.3 Relevant Units
This Standard states values in both SI (Metric) and U.S.Customary units.As an exception, diameter of bolts andflange bolt holes are expressed in inch units only.Thesesystems of units are to be regarded separately as standard.Within the text, the U.s. Customary units are shown inparentheses.The values stated in each system are notexact equivalents; therefore, it is required that eachsystem of units be used independently of the other.Except for diameter of bolts and flange bolt holes,combining values from the two systems constitutesnonconformance with the Standard. The main text ofthis Standard does not contain requirements expressedin Sl units for Class 400 flanges; however,MandatoryAppendix l does contain requirements for this class,expressed in u.s. Customary units only.
2.4 Convention
For determining conformance with this Standard, theconvention for fixing significant digits where limits(maximum and minimum values) are specified shall beas defined in ASTM E29.This requires that an observedor calculated value be rounded off to the nearest unit in the last right-hand digit used for expressing the limit. Decimalvalues and tolerances do not imply a particular method ofmeasurement.
2.5 Denotation
2.5.1 Pressure Rating Designation. Class, followed bya dimensionless number, is the designation for pressure-temperature ratings as follows: Classes 300,400,600,900,1500, and 2500.
2.5.2 Sizes. NPS, followed by a dimensionless number,is the designation for the nominal flange size. NPS isrelated to the reference nominal diameter,DN, used ininternational standards. The relationship is, typically,as follows:
4.1 General
Flange materials shall be in accordance with the re-quirements of ASMEB16.5.Flanges shall be manufacturedas one piece in accordance with the applicable materialsspecification. Except when the purchaser chooses flangeswith nipples welded to the flange taps. assembly ofmultiple pieces into the finished product by welding orother means is not permitted by this Standard.
Changing the distance from the face of the flange to thetap centerline may also be accomplished by changing theraised face height. If flat gaskets are being used and theraised face is completely removed,the user is cautioned tolimit the outside diameter of the gasket or orifice plate tothe outside diameter of raised face, R, in order to ensureproper gasket compression.
9 PRESSURE TAPS
9.1 General
Each orifice flange shall be provided with two pressuretap holes extending radially from the outside diameter ofthe flange to the inside diameter of the flange. Corner tapsmay be used on NPS 11/2 and smaller if space permits. SeeFigure 9.1-1.
For ring joint flanges listed in Tables 5-2 through 5-5,and Mandatory Appendix l, where radial taps will interferewith the ring groove, angular meter taps, as illustrated inFigure 9.1-2,will be required.
9.2 Location
9.2.1 Measurement.The distance between the center-line of the tap and the face of the flange shall be measuredat the bore. Dimensions different than those shown in thetables may be supplied by agreement between thepurchaser and manufacturer.
9.2.2 ldentification. When methods other than thosedescribed in this Standard are used for ring joint flangesrequiring changes to the pressure tap location due tointerference with the ring groove, such changes shallbe identified as agreed by purchaser and manufacturer.9.3 Pipe Connection
Unless otherwise specified by the purchaser, orificeflanges shall be supplied with NPs 1/2 threaded connec-tions.
9.3.1 NPS 1/2 Taps. Pressure tap connections may beinternally threaded in accordance with ASME B1.20.1or socket welding in accordance with ASME B16.11.Each threaded pressure tap connection shall be equippedwith a pipe plug meeting the requirements of para.4.4.Each socket pressure tap connection shall be fittedwith a plastic socket weld plug.