Data Sheet

GX Control Valve and Actuator
D103171X012
Product Bulletin
51.1:GX
March 2012
35
Table 27. Fisher GX, Cavitrol III, Flow Down Through the Port
Cavitrol III, Flow Down
Linear
Characteristic
Trim
Stage
Valve
Size
Port
Diameter
Maximum
Travel
Flow
Coeffi-
cient
Minimum
Throttling
C
v
(1)
Valve Opening–Percent of Total Travel
F
L
(2)
mm mm 10 20 30 40 50 60 70 80 90 100
One
Stage
DN 25
(NPS 1)
22 20
C
v
0.4 0.4 1.1 2.0 2.9 3.7 4.6 5.2 5.9 6.5 7.1 0.97
K
v
0.346 0.346 0.952 1.73 2.51 3.20 3.98 4.50 5.10 5.62 6.14 ---
DN 40
(NPS
1-1/2)
36 20
C
v
1.1 0.4 1.7 4.2 6.6 9.2 11.2 13.6 15.6 17.5 19.4 0.97
K
v
0.952 0.346 1.47 3.63 5.71 7.96 9.69 11.8 13.5 15.1 16.8 ---
DN 50
(NPS 2)
46 20
C
v
2.0 0.8 3.2 5.9 9.1 12.6 15.3 17.8 20.4 22.8 25.2 0.95
K
v
1.73 0.692 2.77 5.10 7.87 10.9 13.2 15.4 17.6 19.7 21.8 ---
1. Valves should not be required to throttle at a C
v
less than the specified minimum C
v
for an extended period. Erosion damage to the valve seats may result.
2. At 100% travel.