FFP valve protecting the hydraulic system from oil loss in the event of sudden leakage of the installation (e.g., hose rupture). During normal operation of the system, the valve allows oil flow in both directions. In the event of a sudden increase in flow (e.g., hose rupture), the valve closes the oil flow in one direction. Permissible flow direction: A → A1 (free), A1 → A (valve). Material: carbon steel, galvanized (body), hardened steel (valve). Sealing: metal-metal. Operating temperature: from -30°C to +100°C.