In Hydraulic engineering (OIL) what is a double acting & single acting cylinder?

Question

A cylinder is used for operations of any machine/process. It may be driven hydraulically or pneumatically. A hydraulic cylinder needs a hydraulic (oil) pump to deliver pressure equiped with relief valves, flow control valves etc.

Answer 1

The terms "Double acting" and "Single acting" refer to pressure driven cylinder motion.  

On SINGLE acting cylinders, the driving pressure, whether air or oil, acts on only one (SINGLE) side of the piston.  A cylinder can be single acting "extend" or single acting "retract", it depends on how the cylinder is ordered, as both are available.  On a single acting cylinder the opposite direction of movement can be achieved by gravity, external load, or an internal compression spring.  In many cylinder designs, the spring rates and loads can be somewhat flexible to suit the individual application needs.

On DOUBLE acting cylinders, the driving pressure, whether air or oil, acts on both (DOUBLE) sides of the piston.  Here the driving pressure creates the extend and the retract motions.  Therefore there are no other forces used to move the cylinder.

Answer 2

A double acting cylinder receives pressure on both sides of the piston, the single acting, only on one side.

Answer 3

Single acting: pumps on "DOWN" stroke

Double acting: pumps on "DOWN" and "UP" strokes

Answer 4

IN SINGLE ACTING CYLINDER YOU USE ONLY ONE SOLENOID TO ACTIVATE THE CYLINDER.WHEN YOU REMOVE SUPPLY FROM THAT SOLENOID COIL, THE CYLINDER RETRACTS ITSELF BY SPRING ACTION.

        IN Double acting you use two coil & no spring in that.