Centre of gravity of the weight
<img src="https://eng-calculations.com/SVG/Hydraulic_engineering/Valves/Centre of gravity of the weight.svg" alt="Centre_of_gravity_of_the_weight" title="Centre_of_gravity_of_the_weight">
https://eng-calculations.com/SVG/Hydraulic_engineering/Valves/Centre of gravity of the weight.svg