The liquid shut-off valve/Recovery Tank Lid for the sewage tank of SUNMAX RT50, RT50+, RT50AC, RT50D, RT50D+ Floor Scrubber Machines. Once the sewage tank is filled with water, the buoyant ball enclosed within this shut-off assembly will prevent further water from entering the sewage tank. This assembly enables the machine to start and stop the liquid flow as needed during cleaning, guaranteeing effectiveness.