Check Valves

A check valve is a key component in pneumatic systems that prevents backflow. It uses a spring-loaded valve core: forward flow opens the valve smoothly, while reverse flow forces it tightly closed.

Fokca offers two series: AKH (inline push-in type) and AKB (male–female threaded type). With a cracking pressure as low as 0.005 MPa, they respond quickly and ensure tight shutoff.

All models are available in both flow directions. Operating range: -100 kPa to 1.0 MPa; temperature: -5°C to 60°C. Widely used for vacuum holding, backflow prevention, drop prevention, and circuit isolation.

What is a Check Valve?

A check valve is a key component in pneumatic systems that controls one-way airflow. It allows compressed air to pass in one direction while automatically blocking reverse flow. When air flows in the forward direction, the valve core is pushed open for smooth passage; when reverse flow occurs, the valve quickly closes under spring force and back pressure, effectively preventing backflow.

In pneumatic systems, check valves are widely used to prevent reverse leakage from cylinders or air tanks, isolate different pressure circuits, and maintain vacuum. They are essential for ensuring system safety, preventing unintended motion, and maintaining stable pressure.

Fokca AKH / AKB Check Valves

AKH Series (Inline Push-in Type)

Designed with an inline structure and push-in fittings, allowing tool-free tube connection for fast installation. Two configurations are available:

· Tube-to-tube (push-in → push-in) for inline pipeline use

· Tube-to-thread (push-in → male thread) for direct installation on equipment or valves
Tube sizes: 4 mm, 6 mm, 8 mm, 10 mm, 12 mm
Thread sizes: M5 and R1/8 to R1/2

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AKB Series (Male–Female Thread Type)

Featuring a compact sleeve design with one female and one male thread, allowing direct connection between pneumatic components or pipelines. Ideal for fixed installations and harsh environments such as coolant exposure or welding spatter.
Thread sizes: M5 and R1/8 to R1/2

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Flow Direction Options

All models are available in two types:

· Forward flow (thread → tube or female → male)

· Reverse flow (opposite direction)
Flexible selection based on pipeline layout.

Why Choose Fokca Check Valves

· Fast response
Cracking pressure as low as 0.005 MPa ensures smooth forward flow and quick system response.

· Reliable pressure resistance, vacuum compatible
Operating range: -100 kPa to 1.0 MPa. Suitable for both vacuum and positive pressure applications, including simple vacuum holding circuits.

· Full range of specifications
Tube sizes: 4 mm, 6 mm, 8 mm, 10 mm, 12 mm
Thread sizes: M5, R1/8, R1/4, R3/8, R1/2
Compatible with a wide range of pneumatic systems.

· Long service life
Made of high-strength engineering plastic or nickel-plated materials, with oil-resistant NBR seals. Heat-resistant and anti-aging, suitable for -5°C to 60°C (non-freezing).

· Compact and easy to install
Inline design with small size and light weight. Push-in fittings allow quick, tool-free installation, ideal for space-limited setups.

Installation Notes

· Installation direction: Follow the flow direction marking on the valve body. Incorrect installation may block airflow or disable the check function.

· Proper insertion: For push-in fittings, insert the tube fully and pull lightly to confirm it is securely locked.

· Air cleanliness: Ensure compressed air is filtered to prevent contaminants from causing valve sticking.

· Not suitable for long-term pressure holding: Some leakage is allowed; not recommended for long-duration pressure retention.

· Throttling impact: If there is throttling on the inlet side, the valve may not fully open even within the specified operating range.

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