ASME B16.12:2019 pdf download

ASME B16.12:2019 pdf download.Cast Iron Threaded Drainage Fittings
1 SCOPE AND GENERAL
1.1 Scope This Standard for cast iron threaded drainage fittings covers (a) sizes and method ofdesignatingopenings in reduc- ing fittings (b) marking (c) material (d) dimensions and tolerances (e) threading (f) ribs (g) coatings (h) face bevel 1.2 Applicability This Standard covers fittings intended foruse in gravity drainage systems subjectonlyto the gravityhead ofwaste liquids at temperatures from ambient to approximately 100°C (212°F). The use of this Standard for pressurized waste handling systems is the responsibility of the user and is subject to the requirements ofany applicable code. 1.3 Quality Systems Requirements relating to the product manufacturers’ Quality S ys tem Pro grams are des crib ed in Nonmandatory Appendix A. 1.4 References Standards and specifications adopted by reference in this Standard are shown in Mandatory Appendix I, whichispartofthis Standard. Itisnotconsideredpractical to identifythe specificeditionofeach referenced standard andspecification inthe text, whenreferenced. Instead, the specific editions of the referenced standards and specifi- cations are listed in Mandatory Appendix I.
4 MATERIALS
4.1 Castings The dimensions prescribed in this Standard (Tables 4.1-1 through 4.1-11) are based on grayiron cast- ings of high quality produced under regular control of chemical and physical properties by a recognized process. The manufacturer shall be prepared to certify that the product has been so produced and that its chem- ical and physical properties, as proved by test specimens, are equal to the requirements specified in ASTM A126. 4.2 Optional Material Drainage fittings are regularly made ofcast iron. At the option ofthe manufacturer, drainage fittings maybe furn- ished of malleable iron complying with the minimum physical requirements of ASTM A197.
5 DIMENSIONS AND TOLERANCES
5.1 Dimensions This Standard states values in both SI (metric) and U.S. Customary units. These systems of units are to be regarded separately as standard. Within the text, the U.S. Customary units are shown in parentheses. The values stated in each system are not exact equivalents; therefore, it is required that each system of units be used independently of the other. Combining values from the two systems constitutes nonconformance with the Standard. Some dimensions of steel pipe from ASME B36.10M are listed for convenience in Nonmandatory Appendix B in inches only. Tolerances ap- plicableto dimensions offittings are specifiedinparas. 5.2 through 5.6. 5.2 Metal Thickness At no point in the castings shall the metal thickness be less than 90% of the values listed in Table 4.1-1. 5.3 Thread Chamber The length ofthread and total length ofthread chamber to shoulder shall not vary from the dimensions shown in thetablesbymorethanplus orminus theequivalentofthe pitch of one thread. 5.4 Outside Diameter and Width of Band Theminus tolerances giveninTable 2.1-1 arepermitted on inspection to applyto the diameter ofthe band and the width of the band.
6 THREADING
(a) All fittings (except roof connections) shall be threaded with American National Standard Taper Pipe Threads (ASME B1.20.1), and the variations in threading shall be limited to one turn small and no turn large. Threaded openings without shoulder, however, shall be limited to one turn large and one turn small from the gaging notch on the plug when using working gages. Roof connections may have taper threads as above or American National Standard Straight Pipe Threads, Free Fitting Mechanical Joint NPSM (ASME B1.20.1). (b) When gaging internal threads, the notch shall be flush with the bottom of the chamfer, which shall be considered as being the intersection of the chamfer cone and the pitch cone of the thread. This depth is approximately equal to one-half thread from the face of the fitting. (c) All threads shall be countersunk a distance not less than one-half thread at an angle approximately 45 deg with the axis of the thread, both for easier entrance in making a joint and for protection of the thread. Counter- sinking shall be concentric with the thread. (d) The length ofthread specified in this Standard shall be measured to include the countersink. (e) The maximum allowable variation in the alignment of threads of all openings of threaded fittings shall be 5 mm/m (0.06 in./ft).