Pneumatica

FLUID POWER FLUID POWER EQUIPMENT TUTORIAL – PNEUMATIC CIRCUTS This work covers part of outcome 3 of the Edexcel standard module: UNIT 21746P APPLIED PNEUMATICS AND HYDRAULICS The material needed for outcome 3 is very extensive and the time required to study it in detail is more than that normally allowed for a single module. This tutorial looks at the design requirements for pneumatic circuits.
OUTCOME 3 Investigate pneumatic and hydraulic circuits • Design and draw a circuit for either pneumatic or hydraulic multi-actuator sequential operation, including emergency stop functions. Design and draw either a pneumatic or hydraulic rotary actuation circuit illustrating speed control in both directions. Design and draw either an ‘electro-pneumatic’ or ‘electrohydraulic’ circuit arrangement. Design and draw an emergency ‘fail safe’ circuit for either a pneumatic or hydraulic application.

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This series of tutorials provides extends the work from outcome 2 to the construction of complete circuits. • • • • Describe further elements needed for controlling pneumatic circuits. Explain the advantages of pneumatics compared to other systems. Explain the classification of pneumatic components. Explain some of the basic principles of control systems.

© D.J.DUNN

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ADVANTAGES OF PNEUMATICS

Pneumatics is used in preference to hydraulics for the following reasons. 1. Easily connected to an air supply and needs no separate power pack. 2. The operation of actuators is fast. 3. No return piping is required; the air is vented to atmosphere. 4. Clean medium with no mess when it leaks. 5. No fire hazard as with oil. Pneumatics is used in preference to electrics for the following reasons. 1. Will not start a fire through electric fault (Intrinsically safe). 2. Air motors are safe when over loaded and does not overheat. 3. Safer for operators (no risk of electrocution). 2. COMPONENT CLASSIFICATION

Pneumatic circuit elements are classed into four primary