Piloted check valve that is used to fill the cylinder chamber behind a piston moving rapidly under its own weight or with a piston for rapid traverse with unpressurised oil from the tank. The high velocity required produces very high flow rates. The pre-fill valve is therefore much larger than the nominal diameters normally required.
The cone is mostly opened for the feed by the negative pressure in the cylinder. For the reflux, on the other hand, it is opened by an opening cylinder. In addition, often a is used to be able to maintain the opening cylinder smaller.
Figure F 38: Pre-fill (and outlet) valve with decompression