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GE Oil & Gas
Table 15: Pneumatics Double Acting Standard Flow
Air Supply
Dry, oil-free, 5 micron filtered air see ISA S7.3
Action
Output 1 increases with increasing signal
Output 2 decreases with increasing signal
Supply Pressure for
Double Acting
25 - 150 psi max. (1.73 to 10.3 bar)
Do not exceed actuator rating.
Air Delivery for
Double Acting
7.2 scf/min. (204 l/min) at 30 psi (2.1 bar) supply
12.8 scf/min. (362 l/min) at 60 psi (4.2 bar) supply
18.3 scf/min. (518 l/min) at 90 psi (6.3 bar) supply
23.8 scf/min. (674 l/min) at 120 psi (8.3 bar) supply
Air Capacity
(flow coefficient)
Loading CV = 0.57
Venting CV = 0.53
Air Consumption for
Double Acting
0.4 scf/min. (11.3 l/min) at 30 psi (2.1 bar) supply
0.85 scf/min. (24.1 l/min) at 80 psi (5.52 bar) supply
Air Supply Failure
Positioner cannot control the failure position of an actuator without a spring. The actuator
can, under different conditions, fail in place, fail open, or fail close. In cases where the
valve must fail to a required position additional accessories are required.
Some overshoot can occur when air pressure returns after a period without air supply
pressure. Always set control set point to 0%, and put the process control system in man-
ual, for smooth recovery from air supply failure.
Loss of Input Signal
Output 1 fails to atmosphere
Output 2 fails to supply pressure.
