Fluid regulation may be achieved by a process performed by a controller. The process may include regulating a first fluid with a fluid-driven fluid regulator, receiving a second fluid, receiving electric power generated using the second fluid, and controlling the fluid regulator with the second fluid. The process may also include determining whether wirelessly sent instructions regarding regulation have been received and, if wirelessly sent instructions regarding regulation have been received, adjusting control of the fluid regulator.
An electrical power supply system comprises an air-powered alternating current electrical generator in which pressurized air from a single source is used to drive an air turbine secured on the shaft of the alternating current electrical generator. One uncontrolled nozzle continuously directs air from the single source to the air turbine. At least a second controlled nozzle directs air from the single source. A solenoid-controlled shut-off valve is placed in a conduit between the source of compressed air and the second nozzle.
A control loop of a control valve is operated using outlet pressure from a pneumatic amplifier as the control parameter. The control loop may be operated continuously in pressure control mode, or may be switched from another mode, such as travel control mode, to pressure control mode in response to certain operating conditions such as operation in the cutoff range, operation with the throttling element engaging a travel stop, or as a backup in the event of primary control parameter sensor failure. Operating the control loop in pressure control mode further allows diagnostics to be performed on the control loop components, even when the system is operating in cutoff range or has engaged a travel stop. The diagnostics may be performed using pressure and displacement sensors normally provided with a positioner. A processor may be programmed to receive data from the sensors and generate fault signals according to a logic sub-routine. The logic sub-routine may include calculating mass flow of control fluid through pneumatic amplifier outlet ports and comparing other operating parameters to detect leaks and blockages in the control loop components. Once a fault is detected, the location of the root cause of the fault may be identified by characterizing operating parameters of the control loop at the time of the fault.
An apparatus including a cantilevered head assembly is disclosed. The apparatus includes a flow control device to control flow proximate to the cantilevered head assembly. In one embodiment, the flow control device includes a blower assembly coupleable to a pressure source and/or vacuum assembly to limit flow disturbances proximate to the cantilevered head assembly.
