ASME B16.39-2019 pdf free
ASME B16.39-2019 pdf free.Malleable ron Threaded Pipe Unions Classes 150, 250, and 300.
4.1 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 identifying the end connection of unions. The number Is not necessarily the same as the fitting inside diameter. The connecting pipe dimension can be found in ASME B36.1OM.
5 MARKING
Unions shall he marked on the nut with the manufacturers name or trademark and nominal pressure class except on bar stock unions, where marking is impractical. Additional markings permitted by MSS SP-25 may be used.
6 MATERIALS
(a) The mechanical properties of the malleable iron castings shall be at least equal to those specified in
ASTM A197/A197M.
(b) Steel bar stock having a yield strength not less than 207 MPa (30 ksi) may be substituted for malleable iron in NPS unions.
(c) Insert rings may be of suitable copper or copper alloy. Where copper-alloy seats are furnished, either the head or tail part of unions produced from bar stock may be solid copper alloy. Such parts must meet the tensile strength requirements listed In Table 6-1.
7 JOINTS AND SEATS
Inserts shall be secured into the ends permanently with no signs of cracking. Inserted seat rings shall be of sufficient width to allow ample hearing for the seating of the male end.
8 THREADING OF PIPE ENDS
8.1 Types of Threads
Pipe ends of head and tall parts shall be threaded with taper pipe threads (ASME B1.20.1) except that NPS % unions made from bar stock may have National Pipe Straight Coupling (NPSC) Internal straight pipe threads.
8.2 Types of Threads
All fittings with internal threads shall be threaded with taper pipe threads per ASME B1.20.1. Variations in threading shall be limited to one turn large or one turn small from the gaging notch when using working gages. The reference point for gaging is the starting end of the fitting. provided the chamfer does not exceed the major diameter of the internal thread. When a chamfer on the internal thread exceeds this limit, the reference point becomes the last thread scratch on the chamfer cone.
9 HYDROSTATIC STRENGTH
Assembled unions shall be capable of withstanding, without rupture or leakage through the shell or at the union joint, an internal hydrostatic pressure of five times the cold 66°C (150°F) pressure rating for I mm.
10 TENSILE STRENGTH
(a) Assembled unions shall be capable of withstanding without rupture the tensile loads shown in Table 6-1.
(b) Tests shall be conducted by attaching threaded steel bars or pipe to each end of the union using the pipe threads. Bars or pipe are to be secured in a tensile testing machine. Load shall be Increased at a uniform rate until the tensile load is attained.ASME B16.39 pdf download.
