ASME B16.39 pdf download Malleable Iron Threaded Pipe Unions Classes 150, 250, and 300
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 offive times the cold 66°C (150°F) pressure rating for 1 min.
10 TENSILE STRENGTH
(a) Assembled unions shall be capable of withstanding, without rupture, the tensile loads shown in Table 2 and Table I-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 pro- duction lot shall be submitted for testing in accordance with section 11. The average outgoing quality level (AOQL), as defined in ANSI/ASQ Z1.4, of the estab- lished 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 coated, they shall be hot dipped in accordance with ASTM A 153 or have an electrodeposited zinc coating conforming to ASTM B 633, Type 1, Service Condition 4. Hot dipped coatings shall be a minimum thickness of 86 m (0.0034 in.) and applied prior to threading. Electrodeposited zinc shall be a minimum thickness of 25 m (0.001 in.) and may be applied either before or after threading.
13.2 Steel Unions NPS 1 ⁄ 8 unions made from steel bar, per para. 6(b) of this Standard, may be either uncoated or have an