AWWA C504-87 PDF

This standard covers rubber-seated butterfly valves, 3 in. through 72 in. in diameter, with various body and end types, for fresh water having a pH greater than 6 and temperatures less than 125 °F, and suitable for maximum steady-state fluid working pressure of 150 psig, a maximum steady-state differential pressure of 150 psi, and a maximum velocity of 16 ft/s.

1.1.1 Body types, classes, and sizes. Valves covered by this standard are furnished in four body types and in classes as follows:
1.1.1.1 Wafer valves. Class 15013, in sizes 3-20 in.
1.1.1.2 Short-body flanged valves. All classes, in sizes 3-72 in.
1.1.1.3 Long-body valves. Class 75A, class 7513, class 150A, and class 150B, in sizes 3-72 in.
1.1.1.4 Mechanical-joint-end valves. Class 15013, in sizes 3-24 in., and all classes in sizes 30-48 in.
1.1.2 Definition of classification. In each case the numeric designation represents the pressure rating, that is, the maximum steady-state fluid working pressure, in pounds per square inch gauge, and also the maximum steady-state differential pressure, in pounds per square inch, for which the valves are designed. The designations "A" and "B" define the flow-rate capabilities with the valve in the fully open position. "A" valves are rated for a maximum velocity of 8 ft/s, and "B" valves are rated for a maximum velocity of 16 ft/s in the piping section upstream of the valve.