applied hydraulics and pneumatics

19P505 APPLIED HYDRAULICS AND PNEUMATICS

Unit 1: ELEMENTS OF FLUID POWER SYSTEM



Lecture 03- Hydraulic fluids and air

,Choice of Working Medium and System

• The choice of medium depends on the application.
• Some of the general, broad rules followed in the selection o
working medium are listed below.
• When the system requirement is high speed, medium press
(usually 6 to 8 bar) and less accuracy of position.
• Then pneumatic system is preferred.
• If the system requirement is high pressure and high precision.
• A fluid system with oil is good.

, Choice of Working Medium and System.....
•When the power requirement is high like in forging presses, sheet
metal press, it is impossible to use air system. Oil hydraulics is the
only choice.
• Air is used where quick response of actuator is required.
• If temperate variation range in the system is large, then use of air
system may run into condensation problems and oil is preferred.
• If the application requires only a medium pressure and high positio
accuracy is required then hydro –pneumatic system is preferred.