järjestysventtiilit

Järjestysventtiilit, known in English as sequence valves, are hydraulic valves that control the sequence of operation in a hydraulic system. They are typically pilot-operated and designed to open or close at a specific pressure. A sequence valve is essentially a pressure-actuated directional control valve. They can be used to ensure that one operation in a hydraulic circuit is completed before another one begins. For example, in a clamping and feeding circuit, a sequence valve can be used to ensure that a workpiece is clamped before the feed cylinder extends.

The operation of a sequence valve relies on a pilot pressure, which is usually taken from the outlet of the valve that controls the first operation. When the pressure in the pilot line reaches the preset cracking pressure of the sequence valve, the valve spool shifts, allowing flow to the next part of the circuit. When the pilot pressure drops below the reseal pressure, the sequence valve returns to its original position, interrupting flow to the second operation. Sequence valves are commonly used in applications such as automated machinery, industrial presses, and robotics where a specific order of operations is critical. They are a simple and effective way to manage sequential movements in hydraulic systems, contributing to both safety and operational efficiency.