hydraulic subtopic

1. Laws governing pneumatic systems

2. Boyle’s Law
Gay-Lussac’s
Law
Charles’ Law
GENERAL GAS LAW

3.  Temperature constant
 Volume will change inversely with absolute pressure

4.  Pressure constant
 Volume will change inversely with absolute
temperature

5.  Volume constant
 Pressure will change inversely with absolute pressure

6.  Combination of Boyle’s, Charles’, Gay-Lussac’s Law
 No parameter is held constant
 Remember, all are expressed in ABSOLUTE terms, not
GAUGE terms!

7.  Gas at 6.895 × 106 Pa and 38 °C is contained in the 50.8
m3 cylinder as shown below. A piston compresses the
volume to 38.1 m3 while the gas is heated to 93 °C.
What is the final pressure in the cylinder?
Ans: 1.09 × 107 Pa

9.  Definition: The use of compressed air in order to
generate force that can produce mechanical
movement
 Pneumatics has been used for carrying out
mechanical tasks for a long time
 Important applications:
◦ Determine the status of processors (sensor)
◦ Switching of actuators by means of final control
elements
◦ Carrying out work (actuators)

10.  Advantages of pneumatics
◦ Raw material freely available
◦ Easily transportable and stored
◦ Can be used in high temperatures
◦ Clean
◦ Fast
◦ Explosion proof
◦ Parts are easy to design & build
 Disadvantages
◦ Preparation
◦ Compression
◦ Force limitations
◦ Noise

11.  Drilling
 Milling
 Sawing
 Finishing
 Forming
 Stamping
 Embossing
 etc

12.  The product development in pneumatics can be
considered in number of:
◦ Actuators
◦ Sensors and output devices
◦ Processors
◦ Accessories
◦ Control systems

13.  Factors in development of pneumatics control
system:
◦ Reliability and safety of operation
◦ Ease of maintenance
◦ Cost (economy, spare parts, etc)
◦ Assembly and connection
◦ Interchangeability and adaptability
◦ Compact design
◦ Operation efficiency