ASME B16.4:2011 pdf free download

ASME B16.4:2011 pdf free download.Gray Iron Threaded Fittings Classes 125 and 250.
7 DIMENSIONS AND TOLERANCES
(a) Center-to-end dimensions in millimeters are given for standard straight and reducing fittings in Tables 2 through 6 (Tables 1-2 through 1-6 are in U.S. Customary units). The sketches of fittings shown in the Standard are representative and for the purpose of illustration.
(b) The dimensions in Tables 2 through 6 (Tables 1-2 through N)) of reducing fittings are for use only when making patterns for the specific reducing fitting in question and do not apply when a larger size pattern is bushed to make the reducing fitting wanted.
(c) The following tolerances shall be permitted:
(1) Metal Thick,wss Tolerances. Metal thickness at no point in the castings shall be less than 90% of the value given in Tables 2 through 6 (Tables 1-2 through 1-6).
(2) Center-to-End Tolerances. Permitted tolerances on the center-to-end dimensions of the fittings are shown in Tables 7 and 1-7. Tolerances for end-to-end dimensions and lengths of couplings and reducers shall be twice those given. The largest opening in a reducing fitting governs the tolerances to be applied to all openings. These tolerances do not apply to return bends and caps.
8 THREADING
(a) All fittings shall be threaded according to ANSI/ASME 81.20.1, and the variations in threading shall be limited to one turn large or one turn small from the gaging notch on the plug when using working gages.
(b) The reference point for gaging internal fittings threads depends upon the chamfer diameter. When the internal chamfer diameter exceeds the major diameterof the internal thread,the reference point is the lastthread scratch on the chamfer cone. When the internalchamfer diameter does not exceed the major diameterof the internal thread, the reference point is the end ofthe fitting (see Fig. 2).
(c) For the purpose of easier entrance in making ajoint and for protection of the thread, all threads shallbe countersunk a distance of not less than one-half thepitch of the thread at an angle of approximately 45 degwith the axis of the thread.Countersinking shall be con-centric with the threads.
(d)The length of the threads specified in all tablesshall be measured to include the countersink.
e)The maximum allowable variation in the align-ment of threads of all openings of threaded fittings shallbe 5.0 mm/ m (0.06 in./ ft) (0.5%slope).
9RIBS
(a)The addition of ribs or lugs is permitted onthreaded fittings. Where ribs are used, it is recom-mended that their thickness be the same as specified formetal thickness of the fitting.
(b)Right-hand couplings shall have not more thantwo ribs.
(c)Right- and left-hand couplings shall have four ormore ribs unless the left-hand opening is clearly marked,in which case the use of ribs is optional with themanufacturer.
10PLUGS, BUSHINGS,AND LOCKNUTS
For dimensions of plugs,bushings, and locknuts tobe used in connection with Classes 125 and 250 grayiron threaded fittings, see ASME B16.14.