When using a meter-out flow control on the cap end of a double acting cylinder, what is being controlled?

In a hydraulic system, using a meter-out flow control on the cap end of a double-acting cylinder specifically controls the speed of extension of the cylinder. This is accomplished by restricting the flow of hydraulic fluid exiting the cap end as the rod extends. As the fluid is metered out, it allows for a controlled, gradual extension of the rod, affecting its speed of movement.

This method is particularly useful in applications requiring fine control over the extension phase, as it ensures that the load is moved at a desired rate, preventing sudden movements that could cause instability or damage. The pressure in the cylinder is influenced by the flow control, but the primary function of the meter-out control is to regulate how quickly the hydraulic fluid can leave the cylinder, thereby dictating the speed of extension. It’s essential for maintaining control over the operation of the cylinder while under load.