Control Valves : Final Control Element in the Control Loop

Control Valves : Final Control Element in the Control Loop free download

Control Valves-Throttling Type;Const;Sizing Software;Selection of valve & actuators;Pneumatic actuators;Calibration

Introduction to Control Valves;Process Control TerminologyProcess Control Valves for oil & gas,power,petro-chemicals-Sliding-Stem Control Valve TerminologyControl Valve FunctionsControl Valve Performance and Characteristics Throttling/Modulating Type Globe type;Ball valve;Butter fly valve; Construction; Major parts; Sizing  Equations valve flow coefficient Cv definition ;Cv determinants;valve charecteristics; ANSI valve leakage class; Sizing Software; Installation Data,process data,Cv calculations, Selection of valve,port area,valve travel, Noise limitations ;Actuators; Pneumatic actuators; I/P converter, valve positioner. Electric Actuators,Hydraulic Actuators ;Process Control Terminology

Accessory: A device that is mounted on the actuator to complement the actuator’s function and make it a complete operating unit. Examples include positioners, supply pressure regulators, solenoids, and limit switches.;Actuator*: A pneumatic, hydraulic, or electrically powered device that supplies force and motion to open or close a valve. Actuator Assembly: An actuator,including all the pertinent accessoriesthat make it a complete operating unit.Backlash: The general name given to a form of dead band that results from a temporary discontinuity between the input and output of a device when the input of the device changes direction. Slack, or looseness of a mechanical connection is a typical example.Capacity* (Valve): The rate of flow through a valve under stated conditions.

Closed Loop: The interconnection of process control components such that information regarding the process variable is continuously fed back to the controller set point to provide continuous automatic corrections to the process variable.

Controller: A device that operates automatically by use of some established algorithm to regulate a controlled

variable. The controller input receives information about the status of the process variable and then provides

an appropriate output signal to the final control element.

Control Loop: Control Range: The range of valve travel over which a control valve can maintain the installed valve gain between

the normalized values of 0.5 and 2.0.

Control Valve Assembly: Includes all components normally mounted on the valve: the valve body assembly,actuator, positioner, air sets, transducers,limit switches, etc.Dead Band: The range through which an input signal can be varied,upon reversal of direction, without initiating an observable change in the output signal.