Check valves, also known as non-return valves or one-way valves, come in several types:
Swing Check Valve:
This type has a disc that swings on a hinge. When fluid flows in the forward direction, it pushes the disc open. When the flow reverses, the disc swings back and closes against the seat, preventing backflow.
Commonly used in larger pipelines and applications where moderate pressure drops are acceptable.
Lift Check Valve:
Features a disc that is lifted off its seat by the forward flow of fluid. When the flow stops or reverses, the disc falls back onto the seat due to gravity or spring force.
Can handle higher flow rates and is often found in industrial applications.
Ball Check Valve:
Contains a ball that is lifted by the fluid flow to open the valve. When the flow stops, the ball drops back by gravity to close the valve.
Compact and suitable for applications with smaller pipe sizes and lower pressure differentials.
Duckbill Check Valve:
Resembles a duck's bill. It is made of flexible material and opens under forward pressure while remaining closed against backflow due to its unique shape.
Commonly used in applications where a tight seal is required and resistance to clogging is important.
Piston Check Valve:
Uses a piston that moves within a cylinder. Forward flow pushes the piston to open the valve, and backflow causes the piston to seal against the seat.
Suitable for high-pressure applications and can handle abrasive fluids.
