1. Unit D: Topic 5 Hydraulic and Pneumatic Systems

2. Hydraulic Systems A closed system using a liquid under pressure. Liquids are incompressible and transmit pressure evenly in all directions.

3. Pneumatic Systems Use air instead of liquids. The air is not sealed in the device, but sucked in from the environment by a powerful motor and passes through the device at high pressure where it escapes. Think of an air pump. The air in the pump is compressed, raising its pressure and forcing it into a ball with a lower pressure.

4. Pneumatics Cont’d Air will always go from an area of high pressure to an area of low pressure. Examples of pneumatic systems include hovercrafts, dentists’ drills, staple guns, sandblasters, and jackhammers.

5. Circulatory System as Hydraulic System Circulatory system is a closed, hydraulic system: Heart = Pump –.moves blood throughout body Blood = Fluid under pressure (120/80 Pa) Blood vessels = container Valves are movable parts which control how much fluid can move through the system.

6. Valves and Veins -Valves are located in veins. When we move our muscles blood is forced up where a valve opens up above and closes after they close. -These valves do not let blood sink down to the bottom of our bodies. They can only move back up.