ASME B16-42:1998 pdf download DUliTllElRON PIPEFLANGESAND FLANGED FlTTlNbS Classes 150 and 30
5 MATERIALS
5.1 Castings
Ductile iron castings covered by this Standard shallconform to ASTM A 395.The castings shall not berepaired by plugging, welding,brazing, or impregnation.
5.2 Bolting
Bolting listed in paras. 5.2.1 and 5.2.2 shall be usedin flanged joints covered by this Standard. Bolting ofother material may be used if permitted by the applicablecode or governmental regulation.
5.2.1 High Strength Bolting. Bolting materialshaving allowable stresses not less than those for ASTMA 193 Grade B7 may be used with any flanged jointat all listed temperatures. The strength of the nut shallbe not less than specified for ASTM A 194 Grade 2H
5.2.2 Low Strength Bolting. Bolting materialswith yield strength equivalent to ASTM A 307 GradeB are considered low strength and may be used forflanged joints at temperatures no greater than 400°Fand only with gaskets described in para. 6.8.
5.2.3 Bolting to Cast iron Flanges. When Class150 ductile iron flanges are bolted to Class 125 castiron flanges, or Class 300 ductile iron flanges are boltedto Class 250 cast iron flanges, it is recommended thatlow strength boltings be used within the limitations inpara. 5.2.2. If high strength bolting is used, it isrecommended that the mating filanges be flat faced andthat full-faced gaskets (ASME B16.5,Fig. El，Group[a materials) extending to the O.D. of the fange be used
5.3 Gaskets
Materials listed in Fig. E1 (ASME B16.5,Anncx E)shall be used. The user is responsible for selection ofgasket materials that will withstand the expected boltload without injurious crushing and which are suitablcfor the service conditions.For low strength bolting described in para. 5.2.2.only gaskets listed in Group la (ASME B16.5，FigE1) shall be used.
6.1 Center-to-Contact Surface and Center-to-End
6.1.1 Standard Fittings. Center-to-contact surfacedimensions are shown in Tables 5 and 9.
6.1.2 Reducing Fittings. Center-to-contact surfaceor center-to-flange edge dimensions for all openingsshall be the same as those of straight size fittings of thelargest opening.The contact surface-to-contact surfacedimensions for all combinations of reducers and eccentric reducers shall be as listed for the larger opening
6.1.3 Side Outlet Fittings. Side outlet elbows,side outlet tees, and side outlet crosses shall have allopenings on intersecting center lines, and the center-to-contact surface dimensions of the side outlet shallbe the same as for the largest opening. Long radiuselbows with side outlet shall have the side outlet onthe radial center line of the elbow, and center-to-contactsurface dimension of the side outlet shal! be the sameas for the regular 90 deg elbow of the largest opening.
6.1.4 Fittings With Bases. Dimensions of basesfor base elbows and base tees are shown in Tables 6and 10.
6.1.5 Special Degree Elbows. Special degreeelbows ranging from 1 deg to 45 deg, inclusive, shallhave the same center-to-contact surface dimensions as45 deg elbows; those over 45 deg to 90 deg, inclusive,shall have the same center-to-contact surface dimensionsas 90 deg elbows. The angle designation of an elbowis its deflcction from straight line flow and is also theangle betwecn the flange faces.
6.2 Facings
6.2.1 General. Class 150 fittings and companionflanges are regularly furnished fat or with a 0.06 inraised face. Class 300 fittings and companion flangesare furnished with a 0.06 in. raised face. The raisedface is included in the minimum flange thickness Q
6.2.2 Facings of Blind Flanges. Blind flangesneed not be faced in the center if, when this centerpart is raised, its diameter is at least 1 in. smaller thanthe inside diameter of the corresponding pressure classfittings, as given in the tables. When the center part
ASME B16-42:1998 pdf download
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