Controls have a function available that is called retraction. This describes an action of the pneumatic cylinder or servo. Retraction can speed up the weld operation when repeating like welds near each other. We don’t want the cylinder to open fully just enough to allow part or gun movement to the next weld location. Then the weld repeats. Another example is to open enough to load the next part but not full open to reduce cylinder travel time.
This is retraction or opening to a weld ready position not the full open position. Welds can be made faster because you do not have to wait for the cylinder or servo to open fully and close again. It only has to move maybe 1” rather than 6” each way and you make more welds per hour. More welds means more parts which is more parts per day which means a good productive day.
Reference: RWMA - Resistance Welding Manual 4th Edition