Abstract： SME B16.42:2021 pdf download.Ductile lron Pipe Flanges and Flanged Fittings Classes 150 and 300. 3.5 Variances From Ratings Except as provided herein, ratings are the maximum allowable working pressure for the corresponding temperature. 3.5...

SME B16.42:2021 pdf download.Ductile lron Pipe Flanges and Flanged Fittings Classes 150 and 300.

3.5 Variances From Ratings

Except as provided herein, ratings are the maximum allowable working pressure for the corresponding temperature.

3.5.1 Safety or ReLief Valve Operation. Under conditions otsafety valve, reliefvalve. or rupture disk operation. the pressure on a flange or flanged fitting may exceed the rated pressure at the pressure-relieving temperature by no more than 1O% Such conditions are necessarily of short duration. Overpressure greater than the aforementioned under pressure-relieving conditions is the

responsibility of the user, subject to the requirements of the applicable code or regulation.

3.5.2 Other Variances. Operating variations (transients) that subject a flange or flanged fitting to pressure in excess of the

rated pressure at the corresponding temperature are the responsibility of the user, subject to the requirements of the applicable

code or regulation.

3.5.3 System Hydrostatic Test. Flanged joints and flanged fittings may be subjected to system hydrostatic tests at a pressure not

to exceed the hydrostatic shell test pressure specified in para. 9.3. Testing at any higher pressure is the responsibility of the

user.

4 SIZE

4.1 NominaL Size

As applied in this Standard, the use of the phrase nominal pipe siz& or the designation NPS followed by a dimensionless number is

for Identifying the end connection of piping, flanges, or flanged fittings. The number Is not necessarily the same as the inside

diameter of the flange or flanged fitting, The diameter of a bolt Is Its nominal size. Use of nominal Indicates that the stated

size or dimension is only for designation, not measurement.

4.2 Reducing Fitting Sizes

Reducing fittings shall be designated by the size of the openings in their proper sequence as indicated in the sketches (see

Figure 4.2.1).

Recommended：