ASME B16.42:2011 pdf free download

ASME B16.42:2011 pdf free download.Ductile lron Pipe Flanges and Flanged Fittings Classes 150 and 300.
flanges and flanged fittings shall have bearing surfaces for bolting that are parallel to the flange face within 1 deg. Any back facing or spot facing shall not reduce the flange thickness below the minimum. Spot facing or back facing shall be in accordance with MSS Sl’-9.
7.5 Reducing Flanges
7.5.1 Drilling, Outside Diameter, Thickness, and Facing Dimensions. Flange drilling, outside diameter, thickness, and facing are the same as those of the standard flange of the size from which the reduction is [wing made.
7.5.2 Threaded Flanges. The hub dimensions shall be at least as large as those of the standard flange of the size from which the reduction is being made. The huh may be larger or may be omitted, as detailed in Table 2.
7.6 Threads for Threaded Flanges
Threaded flanges shall have American National Standard pipe threads, general purpose (inch), conforming to ANSI/ASME B120.1 The thread shall be concentric with the axis of the flange, and variations in alignment shall not exceed 5 mm/rn (0.06 in./lt) (0.5%).
7.6.1 Class 150 Flanges. Class 150 flanges are made without a counterbore. The threads shall be chamfered approximately to the major diameter of the thread at the back of the flange at an angle of approximately 45 deg with the axis of the thread, to afford easy entrance in making a joint and to protect the thread. The chamfer shall be concentric with the thread and shall be included in the measurement of the thread length.
7.6.2 Class 300 Flanges. Class 300 flanges may be made with a counterbore. The threads shall be chamfered to the diameter of the counterbore at the back of the flange at an angle of approximately 45 deg with the axis of the threads to afford easy entrance in making a joint. The counterbore and chamfer shall be concentric with the thread.
7.6.3 Length of Threads. The minimum length of effective thread in reducing flanges shall beat least equal to dimension “Length of Thread” of the corresponding pressure class threaded flange as shown in the tables, but does not necessarily extend to the face of the flange. See Table 2 for reducing threaded flanges.
7.6.4 Threading Tolerances. The gaging notch of the working gage shall come flush with the bottom of the chamfer in all threaded flanges, and shall be considered as the intersection of the chamfer cone and the pitch cone of the thread, This depth of chamfer is approximately equal to one-half the pitch of the thread. The maximum allowable thread variation is one turn large or small from the gaging notch.
7.7 Stud Bolts, Bolts, and Nuts
7.7.1 Alloy Bolting, Alloy steel stud bolts, threaded at both ends or full length, or heavy hex bolts may be used. Heavy hex nuts shall be used with all alloy steel bolting.
7.7.2 Carbon Steel Bolting
(a) Bolts smaller than % diameter shall have square heads or heavy hex heads. Nuts shall be heavy hex.
(b) Bolts 4 diameter and larger shall have square heads or hex heads. Nuts shall be hex or heavy hex.