Abstract： ASME B16.4:1998 pdf download.GRAY IRONTHREADED FITTINGS Classes 125 and 250. 3 SIZE (a) The sizes of the fittings scheduled in Tables 3 through 7 are identified by the corresponding nominal’ pipe size (NPS). (b) For reducing tees and cros...

ASME B16.4:1998 pdf download.GRAY IRONTHREADED FITTINGS Classes 125 and 250.

3 SIZE

(a) The sizes of the fittings scheduled in Tables 3 through 7 are identified by the corresponding nominal’ pipe

size (NPS).

(b) For reducing tees and crosses, the size of the largest run opening shall be given first, followed by the size of the opening at the opposite end of the run. Where the fitting is a tee, the size of the outlet is given last. Where the fitting is a cross, the largest side- outlet opening is the third dimension given, followed by the

opposite opening. The straight-line sketches of Fig. I illustrate how the reducing fittings are read.

4 MARKING

(a) Each Class 125 fitting shall be marked for identification with the manufacturer’s name or trademark.

(b) Each Class 250 fitting shall be marked for identification with:

(c) the manufacturer’s name or trademark, and (2) the numerals “250.”

5 MATERIAL

Castings shall be produced to meet the requirements of ASTM A 126, Specification for Gray Iron Castings for

Valves, Flanges. and Pipe Fittings. Class A, B or C. The manufacturer shall be prepared to certify that the

product has been so produced and that the chemical and physical properties thereof, as proved by test specimens,

are equal to these requirements.

6 DIMENSIONS AND TOLERANCES

(a) Tables of center-to-end dimensions are given for standard straight and reducing fittings. The sketches of

fittings shown in the Standard are representative and for the purpose of illustration.

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