A petrol/diesel drainage pump is a portable, engine-driven machine used to remove or transfer water from one place to another, especially in areas without electricity. It is commonly used for draining flooded areas, irrigation, construction sites, fish ponds, and general water management. The pump consists of an internal combustion engine (petrol or diesel), a pump housing, an inlet (suction pipe), an outlet (discharge pipe), and a frame for easy carrying. It is designed to handle large volumes of water quickly and efficiently.

In operation, the suction pipe is placed into the water source, and the pump is first primed by filling it with water to remove air. The engine is then started using a pull cord or electric start. As the engine runs, it drives the pump impeller, creating suction that draws water into the pump through the inlet pipe. The water is then forced out through the discharge pipe at high pressure. The flow continues as long as the engine is running and fuel is available. The operator can control the flow by adjusting the engine speed. After use, the engine is turned off, and the pump is drained and stored properly.