CPC F16K 37/0083 (2013.01) [F16K 37/0033 (2013.01); F16K 37/0041 (2013.01); F16K 37/005 (2013.01); F16K 37/0091 (2013.01); F16K 31/1221 (2013.01); F16K 31/1262 (2013.01)] | 20 Claims |
1. A flow control, comprising:
a valve assembly comprising a yoke, a pneumatic actuator having an actuator piston and coupled to a first end of the yoke, a valve body coupled to a second end of the yoke, the valve body housing a closure member therein;
a feedback mechanism that is configured to generate data that corresponds with position of the closure member and pressure of an actuating signal that pressurizes the pneumatic actuator; and
a controller mounted to the yoke of the valve assembly between the pneumatic actuator and the valve body and coupled with the feedback mechanism, the controller having operating hardware that is configured to calculate a value for energy use using the data according to,
![]() wherein, when the pneumatic actuator is a single-acting device, t1−t0 is a time interval, W=½ A(P0+P1) (x1−x0), A is the effective area of the actuator piston, P0+P1 is the change in pressure of the actuator signal during the time interval T, and x1−x0 is the change in position of the closure member, and
wherein, when the pneumatic actuator is a double-acting device,
![]() Aa is the effective area of side “A” of the actuator piston, Ab is the effective area of side “B” of the actuator piston, Pa0 is pressure of the actuator signal on side “A” at time t0, Pb0 is pressure of the actuator signal on side “B” at time t0, Pa1 is pressure of the actuator signal on side “A” at time t1, and Pb1 is pressure of the actuator signal on side “B” at time t1.
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