AWWA C110-12 pdf download.Ductile-Iron and Gray-Iron Fittings
3. Attention is directed to an apparent confict between this standard and ASME B16.1, Cast Iron Pipe Flanges and Flanged Fittings, with regard to pressure ratings for fanged fttings.
In ANSI/AWWA C110/A21.10, fanged joint fttings are rated for 150- or 250-psi (1,034- or 1,724-kPa) working pressure, depending on the material, that is, gray iron or ductile iron; the wall thickness of gray iron; and the size of the ftting. Te ratings of these fttings were established on the basis of hydrostatic testing of fttings to bursting and provide for a factor of safety of at least 3.0 at the rated working pressure and at ambient temperature. ANSI/AWWA C110/A21.10 fanges that are adequate for water service of 250-psi (1,724-kPa) working pressure have facing and drilling identical to ASME B16.1 class 125 fanges and match class 125 B16.1 fanges that for service at –20° to 150°F (–28.9° to 65.6°C) are rated for only 150 to 200 psi (1,034 to 1,724 kPa), depending on the fange size and the class or grade of iron.
ASME B16.1 describes both separate fanges and fanged fttings of gray iron for service at both ambient and elevated temperatures. Te pressure-temperature ratings of these fanges, as stated in ASME B16.1 and stated on the fyleaf of that standard, are not based on burst strength, but have evolved over an extended period of time of satisfactory performance in a wide range of general service conditions. Tese ratings encompass pressure combined with elevated temperature, stresses imposed by piping, thermal stresses caused by temperature variations, and many other conditions causing stress in the fange or ftting.
4. Although this standard does not detail the orientation of bolt holes in the fanges of the mechanical joint, it is at times convenient or necessary to have the bolt holes specially oriented. Te normal but not universal practice is to have the bolt holes straddle the vertical centerline of the fttings, valves, and hydrants. (Te vertical center- line of a ftting is determined when the ftting is in the position to change the direction of fuid fowing in a horizontal plane. With standard base bends and standard base tees, the vertical centerline is determined when the ftting is in a position to change the fuid fowing in a vertical plane.) If special orientation is known to be necessary, it should be stated on the purchase order.AWWA C110-12 pdf download.