Technical Instructions
Document No. 155-199P25
October 24, 2005
Page 4
Siemens Industry, Inc.
Figure 1. Water Capacity Graph.
Selection Example
See Figure 1.
Select a valve given:
Required flow = 20 gpm.
Desired pressure drop = 5 psi.
Choose a 1-inch (25 mm) valve, Cv 10.
Table 5. Close-off Pressures.
Action
Valve Size Inches (mm)
SSB Actuator
psi (kPa)
NC
Upper port
1/2", 0.4< Cv <1.6
(15 mm, 0.34< Kvs <1.37)
70 (483)
1/2", 2.5< Cv <4
(15 mm, 2.15< Kvs <3.44)
40 (276)
3/4" and 1" (20 mm and 25 mm)
30 (207)
NO
Bottom port
1/2", 0.4< Cv <1.6
(15 mm, 0.34< Kvs <1.37)
25 (172)
1/2", 2.5< Cv <4
(15 mm, 2.15< Kvs <3.44)
15 (103)
3/4" and 1" (20 mm and 25 mm)
10 (69)
