The new pilot operated check valves enable flow in one direction, which in return blocks the flow in the opposite direction: thus preventing pneumatic cylinders from unintentionally deaerating in the event of a pressure drop. If necessary, users can open the valves by inserting a defined pressure and force ventilating the cylinders. The pilot operated check valve is designed for a working pressure range of 1 to 10 bar and a temperature range of -10 to +70 °C. As an ideal connection supplement, Eisele’s swivel joint in series 25 (page 215), which in addition to activation through compressed air, can also be used with manual activation.