Double acting cylinders use pressurized air to extend and retract the piston through two connection ports. They have four main parts: the cylinder, plunger, piston rod, and connection ports. When port A is pressurized, the piston extends out and port B exhausts air, and when port B is pressurized the piston retracts and port A exhausts air. Double acting cylinders generate thrust in both directions from air pressure and are more compact and generate constant force compared to single acting cylinders.

2. BY
CH.NARENDRA CHOWDARY
M2 SEC

3. Double Acting Cylinders
 Is a cylinder designed to use air to
extend and retract the piston.
 Double acting cylinders are far more
popular than single acting.
 They are available in single rod end and
double rod end, cushioned and non-
cushioned.

4. PARTS OF DAC:
I. Cylinder
II. Plunger
III. Piston rod
IV. Connection ports

5. A B
Cylinder is at rest when neither
port is energized.
When A is pressurized
the piston extends out
and B exhausts air.
When B is pressurized, the piston
retracts and A exhausts air. The
cylinder is now back to its original
state.

6. WORKING:
Thrust is developed
in both extending
and retracting
directions as air
pressure is applied
to the appropriate
ports.

7. Air cylinders are available in a variety of
sizes and can typically range from a small
2.5 mm air cylinder.
An 400 mm diameter air cylinders which
would impart enough force to lift a car.
Some pneumatic cylinders reach 1000 mm
in diameter.

8. Extending Stroke: Fe = (p / 4) * D² x P
Retraction Stroke: Fr = (p / 4) * (D²-d²) x P
FOR DOUBLE ACTING CYLINDER

9. Required Air Flow Rate
Max Pressure/Required
Pressure
Capable Force
Capable Torque
Max RPM
Linear Velocity
S PS

10. • More compact body when compared
to single acting.
•Constant force(Dependent on stroke)
• Higher force with smaller bore size
due to absence of spring.

11. • Every movement uses compressed air.
• No defined position in the event of
compressed air failure.