Mechanical emergency valve operator is a manual control assembly designed for the bottom valves/emergency shutoff valves of fuel tank trucks and fuel tanker semi-trailers. Suitable for multi-compartment tanks, the valve operator uses independent control levers to operate the corresponding bottom valve of each compartment. Each lever is connected to the bottom valve by a control cable, enabling remote manual opening and closing of the fuel transfer line during loading and unloading. This valve operator is a standard safety component for tankers carrying hazardous liquids.