ASME B16.4-2006 pdf download

ASME B16.4-2006 pdf download.Gray lron Threaded Fittings Classes 125 and 250.
1.6 Convention
For the purpose of determining conformance with this Standard, the convention for fixing significant digits where limits, maximum and minimum values are specified, shall be rounded as defined in ASTM E 29. This requires that an observed or calculated value shall be rounded off to the nearest unit in the last right- hand digit used for expressing the limit. Decimal values and tolerance do not imply a particular method of measurement.
1.7 Denotation
1.7.1 Pressure Rating Designation. Class, followed by a dimensionless number, is the designation for pressure—temperature ratings as follows: Class 125 and Class 250.
1.7.2 Size. NPS, followed by a dimensionless number, is the designation for nominal fitting size. NPS is related to the reference nominal diameter, DN, used in international standards. The relationship is, typically, as follows:
3 SIZE
3.1 Nominal Pipe Size
As applied in this Standard, the use of the phrase “nominal pipe size” or the designation NPS followed by a dimensionless number is for the purpose of identifying the end connection of fittings. The number is not necessarily the same as the fitting inside diameter.
3.2 Reducing Fittings
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
(1) the manufacturer’s name or trademark
(2) the numerals “250”
5 MATERIAL
Castings shall be produced to meet the requirements of ASTM A 126, 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.