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ASME B16.51-2021 pdf download

ASME B16.51-2021 pdf download.Copper and Copper Alloy Press-Connect Pressure Fittings.
4 SIZE The size designations ofthe fittings shown in the tables ofthis Standard correspond to standard water tube sizes as shown in ASTM B88. The size designations of the threaded ends correspond to nominal pipe sizes as shown in ASME B1.20.1. Fittingsshallbedesignatedbythesizeoftheopeningsin the sequence illustrated in Figure 3.1-1. 5 MARKING Each fitting shall be permanently marked with the manufacturer’s name or trademark in accordance with ANSI MSS SP-25. Marking on fittings less than nominal size 1 ∕ 2 or on any fitting where itdamages joining surfaces is not required. 6 MATERIAL 6.1 ð21Þ Wrought Copper Alloys (a) Fittings shall be made from copper alloy UNS No. C10200, C12000, C12200, or C23000. (b) Othercoppers andcopperalloys shallbepermitted, provided theirchemical composition contains a minimum of80% copper and a maximum of16% zinc, and provided the fittings produced from the copper alloy meet all the mechanical andcorrosion-resistantproperties forthe end purposes of the fittings. For potable water applications, fittings shall be produced from low-lead (0.25% or less) copper alloys and shall meet all the mechanical and corrosion-resistant properties for the end purposes of the fittings. The composition of the copper alloy shall not inhibit joining to the tube or to other fittings. The special requirements shall be as follows: (a) Z1 designates compliance with NSF/ANSI 61. (b) Z2 designates the compression set. Elastomeric material shall be tested for compression set as per the ASTM D2000 suffix requirements of B35 in accordance with ASTM D395, Method B, plied, for 22 h at 125°C. The maximum allowed compression set shall be 30%. (c) Z3 designates chloramine resistance, which is determined by testing for 1 008 h at 70°C (158°F) in a solution containing 50 ppm total chlorine, per ASTM D6284; this shall be checked and refreshed daily. Upon completion of the test, the change in volume shall be less than 30%, and the change in durometer hardness shall be a maximum of6. There shall be no visual degrada- tion of the elastomeric material. (d) Z4 designates resistance ofthe elastomer to copper degradation. The test shall be conducted in accordance with para. 14.9.1. Upon completion of the test, the change in volume shall be less than 30%, and the change in durometer hardness shall be a maximum of 6. There shall be no visual degradation ofthe elastomeric material. 6.4 Seal Lubricant The only seal lubricant that shall be used is that speci- fied by the manufacturer. 7 LAYING LENGTHS Due to widely varying manufacturing processes, mean- ingful laying length requirements of fittings cannot be established. Consult the manufacturer for these dimen- sions.
10.2 Threading Tolerances NPT threads shall be checked by use of a plug or ring gage in either standard or limit types. When gaging internal taper threads, the plug gage shall be screwed hand-tight into the fitting. The reference point for gaging internal product-threads depends on the chamfer diameter. When the internal chamfer diameter exceeds the major diameter of the internal thread, the reference point shall be the last thread scratch on the chamfer cone. Otherwise, when the internal chamfer diameter does not exceed the major diameter of the internal thread, the reference point shall be the end of the fitting. In gaging external taper threads, the ring gage shall be screwed hand-tight on the external thread. On the external thread, the ring gage shall be flush with the end of the thread. Tolerance for an internal threaded end having an internal shoulder shall be from the gage reference point(notch) to oneturnsmall. Toleranceforaninternally threaded end without a shoulder and for an externally threaded end shall be from one turn small to one turn large. 10.3 Design of Threaded Ends The wrenchingsection ofinternallythreaded ends shall be polygonal, and the wrenching section of externally threaded ends shall be furnished with either polygon or flats, at the manufacturer’s option. 11 ALIGNMENT The maximum allowable deviation in the angular align- ment of any end from the specified axis position shall be 1 ∕ 2 deg (1 deg total). See Figure 11-1. 12 GAGING 12.1 Preferred Gaging Method of Press-Joint Ends Thepreferredmethodofgagingthediametertolerances for external and internal ends shall be by the use ofplain plug and ring gages designed to hold the product within the limits established in Table 9.1-1. Gage tolerances shall be Class ZM, as defined in ANSI B4.4M.

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