A piston pump works by using the reciprocating motion of a piston inside a cylinder to draw fluid in and push it out.
A piston pump is a type of positive displacement pump. This means it moves a fixed amount of fluid with each stroke of the piston. Here's the basic process:
The Components
The main parts of a piston pump include:
- Cylinder: A chamber where the piston moves.
- Piston: A disc or cylinder that moves back and forth (reciprocates) within the cylinder.
- Inlet Valve: A one-way valve that allows fluid to enter the cylinder.
- Discharge Valve: A one-way valve that allows fluid to exit the cylinder.
The Working Cycle
The operation typically involves two main strokes:
-
Suction (Intake) Stroke:
- The piston moves away from the inlet valve, increasing the volume inside the cylinder.
- This creates a lower pressure inside the cylinder compared to the inlet pressure.
- The inlet valve opens, and fluid is drawn into the cylinder.
- The discharge valve remains closed.
-
Discharge (Pressure) Stroke:
- The piston reverses direction and moves towards the inlet valve.
- This action is being pushed in, significantly reducing the volume inside the cylinder, so we go from large volume to small volume.
- This rapid reduction in volume and the piston's movement is pushing the liquid away, building pressure.
- The inlet valve closes due to the increased pressure.
- When the pressure inside the cylinder exceeds the discharge pressure, the discharge valve opens, and the fluid is expelled from the pump.
This cycle repeats, creating a continuous flow of fluid. The reference highlights the need for a good discharge or inlet and discharge separation, which is precisely the function of the one-way valves – they ensure that fluid flows in the correct direction during each stroke and prevent backflow.
Key Aspects
- Positive Displacement: Each stroke displaces a specific volume of fluid, making the flow rate directly proportional to the pump's speed.
- High Pressure: Piston pumps are capable of generating very high pressures, making them suitable for applications like hydraulic systems or high-pressure cleaning.
- Valves are Crucial: The reliable operation of the inlet and discharge valves is essential for the pump to function correctly and maintain flow separation.
Piston pumps are used in various applications, from small hand pumps to large industrial pumps, due to their ability to handle a wide range of fluids and generate high pressures.
