ASME B16.39-2009 pdf free download.Malleable lron Threaded Pipe Unions Classes 150,250, and 300.
(a) The mechanical properties of the malleable iron castings shall be at least equal to those specified in ASTM
(b) Steel bar stock having a yield strength of 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 cupper 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 2 and Table 1-2,
7 JOINTS AND SEATS
Inserts shall be secured into the ends to become a permanent part of them with no signs of cracking. Inserted seat rings shall be of sufficient width to allow ample bearing for the seating of the male end.
8 THREADING OF PIPE ENDS
8.1 Types of Threads
Pipe ends of head and tail parts shall be threaded ‘with taper pipe threads (ASME B1.20.1) except that NI’S unions made from bar stock may have NC internal straight pipe threads.
The variation in taper threading shall Lw limited to one turn large and one turn small from the gaging face of the ring and gaging notch on the plug when using working gages.
The reference point for the internal product thread is the starting end of the fitting. providing the chamfer does not exceed the major diameter of the internal thread. When a chamfer on the product thread exceeds this limit, the reference point becomes the last thread scratch on the chamfer cone. Allowance must be made for depth of counterbore on counterbored fittings.
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 66CC (I5OCF) pressure rating for I mm.
10 TENSILE STRENGTH
(a) Assembled unions shall be capable of withstanding, without rupture, the tensile loads shown in Table 2 and Table 1-2.
(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,
11 AIR PRESSURE TEST
Assembled unions selected in accordance with section 12 shall be tested with air at a minimum pressure of 2.8 bar (40 psi).
12 SAMPLING FOR AIR PRESSURE TEST
A random sample of unions representative of the production lot shall be submitted for testing in accordance with section Ii. The average outgoing quality level (AOQL), as defined in ANSI/ASQ Z1.4, of the established acceptable sampling plans used shall not exceed 2%. A lot, for purposes of this Standard, is defined as the number of unions of the same size, design, and pressure rating submitted for testing at any one time.
13.1 Malleable Iron Unions
When malleable iron unions are zinc coaled, they shall be hot dipped in accordance with ASTM A 153 or have an electrodeposiled zinc coating conforming to ASTM B 633, Type I, Service Condition 4. hot dipped coatings shall be a minimum thickness of 86 p.m (0.0034 in.) and applied prior to threading. Electrodeposited zinc shall be a minimum thickness of 25 p.m (0.001 in.) and may be applied either before or after threading.
13.2 Steel Unions