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A functional block diagram, in systems engineering and software engineering, is a block diagram that describes the functions and interrelationships of a system. The functional block diagram can picture: [1] functions of a system pictured by blocks; input and output elements of a block pictured with lines; the relationships between the functions ...
Air pressure acts on a piston or bellows diaphragm creating linear force on a valve stem. Alternatively, a quarter-turn vane-type actuator produces torque to provide rotary motion to operate a quarter-turn valve. A pneumatic actuator may be arranged to be spring-closed or spring-opened, with air pressure overcoming the spring to provide movement.
Diaphragm valves can be controlled by various types of actuators e.g. manual, pneumatic, hydraulic, electric etc. The most common diaphragm valves use pneumatic actuators; in this type of valve, air pressure is applied through a pilot valve into the actuator which in turn raises the diaphragm and opens the valve. This type of valve is one of ...
A pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Valves require little pressure to operate and usually double or triple the ...
A function analysis diagram (FAD) is a method used in engineering design to model and visualize the functions and interactions between components of a system or product. It represents the functional relationships through a diagram consisting of blocks, which represent physical components, and labeled relations/arrows between them, which represent useful or harmful functional interactions.
The schematic diagram of a radio does not show the width of each connection in the printed circuit board, but the layout does. To make an analogy to the map making world, a block diagram is similar to a highway map of an entire nation. The major cities (functions) are listed but the minor county roads and city streets are not.
Each block in the first level diagram can then be expanded to a series of functions, as shown in the second level diagram for "perform mission operations." Note that the diagram shows both input (transfer to operational orbit) and output (transfer to space transportation system orbit), thus initiating the interface identification and control ...
An automatic control valve consists of three main parts in which each part exist in several types and designs: Valve actuator – which moves the valve's modulating element, such as ball or butterfly. Valve positioner – which ensures the valve has reached the desired degree of opening. This overcomes the problems of friction and wear.