ASME B16.42:2016 pdf free download

ASME B16.42:2016 pdf free download
ASME B16.42:2016 pdf free download.Ductile Iron Pipe Flanges and Flanged Fittings
7.6 Threads for Threaded Flanges Threaded flanges shall have American National Standard pipe threads, general purpose (inch), conform- ing to ANSI/ASME B1.20.1. The thread shall be concen- tric with the axis of the flange, and variations in alignment shall not exceed 5 mm/m (0.06 in./ft) (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 ofthe 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 cham- fered 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 inreducing flanges shall be atleastequal 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 consid- ered as the intersection of the chamfer cone and the pitchcone ofthethread. This depthofchamferis approx- imately equal to one-half the pitch of the thread. The maximum allowable thread variation is one turn large or small from the gaging notch.