Latco (Check) Valves: Function, Types, and Applications

A Latco valve (commonly called a check valve or non-return valve) permits fluid flow in one direction only, preventing backflow.

Components

• Valve seat: Stationary, installed in pipeline.
• Valve disc (poppet, ball, flap): Movable closure element.
• Spring (optional): Assists closure, reduces water hammer.

Operation

• Forward flow: pressure pushes disc off seat → flow.
• Reverse/no flow: spring/gravity seats disc → blocks backflow.

Common Types

1. Swing Check: Hinged disc swings open/closed; low pressure drop, horizontal/vertical up.
2. Lift Check: Guided disc lifts vertically; for high pressure, horizontal only.
3. Ball Check: Ball seats in conical seat; self-cleaning, viscous fluids.
4. Diaphragm Check: Flexible elastomer disc; sanitary, slurry service.
5. Wafer/Dual-Plate: Compact, between flanges; spring-loaded plates.

Applications

• Pump/compressor discharge protection
• Plumbing, HVAC, fire suppression
• Process industries: chemical, oil/gas, water treatment
• Prevent siphoning, water hammer, contamination

Selection depends on fluid, pressure, temperature, flow orientation, and maintenance access.