‘Q’ dimension is the minimum allowable pipe or flange inside diameter at the centered body face to protect the disc sealing edge against damage when opening the valve.
| Size (in) | Size (mm) | 10° | 20° | 30° | 40° | 50° | 60° | 70° | 90° |
|---|---|---|---|---|---|---|---|---|---|
| 24 | 600 | 220 | 1,000 | 2,300 | 4,000 | 6,400 | 10,000 | 16,500 | 30,000 |
| 30 | 750 | 340 | 1,500 | 3,600 | 6,200 | 9,900 | 16,000 | 26,000 | 47,000 |
| 36 | 900 | 500 | 2,600 | 5,200 | 9,100 | 15,000 | 23,000 | 38,000 | 70,000 |
| 42 | 1,050 | 670 | 3,000 | 7,000 | 12,000 | 19,500 | 31,000 | 51,000 | 93,000 |
| 48 | 1,200 | 870 | 4,000 | 9,000 | 16,000 | 25,000 | 40,000 | 66,000 | 120,000 |
Cv is the valve flow capacity expressed as the flow rate of 60°F water, in US gallons per minute, which produces a 1 psi pressure drop across the valve.
