ASME B16.15:2018 pdf free download – Cast Copper Alloy Threaded Fittings
2.5 Time of Purchase
Manufacture, orInstallation The pressure–temperature ratings in this Standard are applicable upon its publication to all fittings within its scope that otherwise meet its requirements. For unusedfittings maintainedininventory, themanufacturer of the fittings may certify conformance to this edition provided it can be demonstrated that all requirements of this edition have been met. Where such components were installed in accordance with the pressure–tempera- ture ratings of an earlier edition of this Standard, those ratings are applicable except as may be governed by the applicable code or regulation.
3.2 Rating
Pressure–temperature ratings are independent of the contained fluid and are the maximum allowable pressures at the tabulated temperatures. Intermediate ratings may be obtained bylinear interpolation between the tempera- tures shown. Thetemperatureshownforthecorrespondingpressure rating shall be the material temperature ofthe pressure- retaining structure. It may be assumed that the material temperature is the same as the fluid temperature. Use ofa pressure rating at a material temperature other than that ofthe contained fluid is the responsibility ofthe user and subject to the requirements of any applicable codes and regulations.
4.2 Reducing Sizes
In the case of reducing tees, crosses, and Y branches (laterals), the NPS of the largest run opening shall be givenfirst, followed bythe NPS ofthe openingatthe oppo- site end of the run. Where the pipe fitting is a tee or Y branch (lateral), the NPS of the outlet is given last. Where the pipe fitting is a cross, the largest side-outlet opening is the third dimension given, followed by the opening opposite. The straight line sketches of Figure 4.2-1 illustrate how the reducing pipe fittings are read.
6 MATERIAL
(a) Castings shall be produced to meet the require- ments of ASTM B62, alloy UNS C83600, or the chemical and tensile requirements of ASTM B584, alloys UNS C83800 or UNS C84400, and in all other respects shall conform to the requirements of ASTM B62.
(b) Bar stock, when used for manufacturing smaller sizes of wrought plugs, bushings, caps, and couplings, shall be in accordance with the requirements of ASTM B16, alloy UNS C36000, or ASTM B140, alloy UNS C32000 or UNS C31400.
7.1.1 Countersinks and Chamfers. All internal taper pipethreadsshallbecountersunkorchamferedadistance notless than one-halfthe pitch ofthe thread atan angle of approximately45 degwith the axis ofthe thread. External taperpipe threads shall be chamferedatanangle between 30 deg and 45 deg with the axis for easier entrance in making a j oint and protection of the thread. Countersinking and chamfering shall be concentric with the threads. The length of threads specified in all tables shall be measured to include the countersink or chamfer.”
7.1.4 External Threading. All externally threaded fittings shall be threaded with ASME B1.20.1 NPT threads. The reference point for gaging is the end of the thread, provided the chamfer is not smaller than the minor diameter of the external thread. When a chamfer on the external thread exceeds this limit, the reference point becomes the last thread scratch on the chamfer cone.
7.2Gaging Tolerances
For taper pipe threads, the variation in threading shall be limited to one turn large or one turn small from the gaging notch on the plug or the gaging face of the ring when using working gages. For straight pipe threads, the variation in threading shall be limited to 1 1 ∕ 2 turns large or 1 1 ∕ 2 turns small from the gaging notch on the plug when using working gages.