ASME B16.50:2001 pdf free download.WROUGHT COPPERAND COPPER ALLOY BRAZE-JOINT PRESSURE FITTINGS.
9.2 Ovality of Fitting End (C or FTG)
Maximum tmality of the lifting braze-joint end shall not exceed l% of the maximum diameters shown in Table 3 (Table 13). The average of the maximum and miflimtllfl diameters shall be within the dimensions shown in the table.
9.3 Inside Diameter of Fitting
The minimum cross-sectional area of the inside diameter through the fining body shall not be less than the theoretical minimum area defined by diameter “0” in Table 3 (Table 13). The out.of.roundncss condition of the cross.scctional area shall not exceed the value shown in Table 3 (Table 13).
For reducer or adapter fittings. the smallest end diameter shall apply. provided that this diameter does not restrict the other outlets.
9.4 Wall Thickness
The luininluin wall-thickness shall not be less than shown in Table 3 (Table 13).
10 THREADED ENDS
Fitting threads shall be right-hand, conforming to ASME Bl.20.l. American National Standard for Pipe Threads. General Purpose (Inch). They shall he taper threads (NV!’).
10.1 Countersink or Chamfer
All internal threads shall be countersunk a distance no less than one-half the pitch of the thread, at an angle of approximately 45 deg with the axis of the thread. All external threads shall be chamfered at an angle of 30 deg to 45 deg from the axis. Countersinking and chamfering shall he concentric with the threads.
The length of threads shall be measured to include the countersink or chamfer.
10.2 Threading Tolerances
Tapered pipe threads (NV) shall be checked by use of plug or ring gauges in either standard or limit types. When gauging internal taper threads, the plug gauge shall be screwed handtight into the fitting. The reference point for gauging internal product-threads depends on the chamfer diameter. When the internal-chamfer diameter exceeds the major diameter of the internal thread, the reference point shall be the last thread scratch on the chamfer cone. Otherwise, when the internal-chamfer diameter does not exceed the major diameter of theinternal thread, the reference point shall be the end ofthe fitting. In gauging external taper threads,the ringgauge shall be screwed handtight on the external thread.On the external thread,the ring gauge shall be flushwith the end of the thread.
Tolerance for an internally threaded end having aninternal shoulder shall be from the gauge referencepoint (notch) to one turn small. Tolerance for aninternally threaded end without a shoulder,and for anexternally threaded end,shall be from one turn smallto one turn large.