What is the function of a check valve in a pneumatic circuit?

What is the function of a check valve in a pneumatic circuit?

• A. Allows air flow in one direction only, preventing backflow.
• B. Diverts flow to two outputs.
• C. Shuts off flow completely.
• D. Increases pressure in the line.

Answer: (A)

In pneumatics, a check valve is used to prevent backflow while allowing forward flow. It works by letting air move freely in the intended direction, then sealing off if pressure tries to push it backward. This keeps pressure and flow in the desired path, protecting components and maintaining predictable operation when other parts of the circuit change state. It doesn’t divert flow to two outputs, it doesn’t shut off flow entirely, and it doesn’t increase pressure in the line. The key idea is one-way flow: forward movement is allowed, reverse movement is blocked.

In pneumatics, a check valve is used to prevent backflow while allowing forward flow. It works by letting air move freely in the intended direction, then sealing off if pressure tries to push it backward. This keeps pressure and flow in the desired path, protecting components and maintaining predictable operation when other parts of the circuit change state.

It doesn’t divert flow to two outputs, it doesn’t shut off flow entirely, and it doesn’t increase pressure in the line. The key idea is one-way flow: forward movement is allowed, reverse movement is blocked.