as designed, as hydraulically-actuated devices may be present in the section isolated by the fuse. Depending on the system, hydraulic fuses may reset automatically after a delay, or may require manual re-opening. Forklift main hoist cylinders are usually equipped with a fuse built into the hose adapter at the base of the cylinder that resets immediately upon stopping the flow. In dam spillways In the design of a spillway for a dam, a fuse plug is a water retaining structure designed to wash out in a controlled fashion if the main dam is in danger of overtopping due to flood, and if the normal spillway channel is insufficient to control the overtopping. See also Relief valve Safety valve Hydraulics Safety valves