Control of Pneumatic Energy Unit Six Control of Pneumatic Energy Pneumatic energy must be controlled in order to accomplish useful work and be safe. There are three quantities that must be controlled. Pressure Direction Flow

Valves As stated earlier, there are three quantities that must be controlled and they are all controlled by valves. All valves consist of basically the same parts. They each have a body, internal moving part, and ports to connect the valve to the system.

Control of Pressure In most cases, the pressure generated at the compressor and what is required by the system are different so pressure has to be controlled at two locations.

Pressure Control Switch Maximum pressure control in pneumatics is usually accomplished by the use of an electrical switch although some large systems use mechanical devices. With the switch, contacts are opened or closed to stop an electric motor.

Pressure Control Valve Safety Relief If for some reason the electrical switch or mechanical device should fail to stop the compressor at the right time, a fail safe device opens to permit the escape of air.

Pressure Control Valve Pressure Regulator The pressure regulator valve controls pressure in branch legs of a pneumatic system such as drop legs for individual machines.

Directional Control Valve Fluid must be directed to different points in order to control an actuator. The DCV controls where the fluid goes.

Flow Control Valve The basic operation of the flow control valve is to “pinch” off flow to adjust the speed of an actuator.

Simple Pneumatic System This type of drawing is referred to as a “pictorial”diagram.

Simple Hydraulic System This illustration is called a “schematic” diagram and is commonly used in industry.

Hydraulic Symbols These are some of the most often used symbols you will see in industry and this course. Make a point to become familiar with them.