This standard covers rubber-seated butterfly valves, 3 in. (75 mm) through 72 in. (1,800 mm) in diameter, with various body and end types, for fresh and reclaimed water having a pH range from 6 to 12 and a temperature range from 33° to 125°F (0.6° to 52°C). This standard covers rubber-seated butterfly valves suitable for a maximum steady-state fluid working pressure of 250 psig (1,723 kPa, a maximum steady-state differential pressure of 250 psi (1,723 kPa), and a maximum velocity of 16 ft/s (4.9 m/s).

Valves covered by this standard are furnished in four body types and in classes as follows:

Wafer valves, Class 150B, in sizes 3 in. – 20 in. (75-500 mm)
Short-body and long-body flanged valves in classes 25A, 25B, 75A, 75B, 150A, and 150B, in sizes 3 in. – 72 in. (75 mm – 1,800 mm), and class 250B in sizes 3 in. – 48 in. (75 mm – 1,200 mm)
Mechanical-joint-end valves, classes 150B and 250B, in sizes 3-24 in. (75-600 mm), and classes 25A, 25B, 75A, 75B, 150A, 150B, and 250B in sizes 30 in. – 48 in. (750 mm – 1,200 mm)

Major revisions to htis edition of hte standard affect the following: