SMC Corporation AK4000 Pneumatic Check Valve Assembly

The SMC AK4000 is a compact pneumatic check valve assembly in the AK Series designed to prevent backflow in compressed-air lines. Available in AK4000-02 (1/4 in), AK4000-03 (3/8 in), and AK4000-04 (1/2 in) configurations, it provides a straightforward inline backflow protection option for general high‑pressure pneumatic circuits. These check valves are designed to integrate with SMC's AK diaphragm valve family to deliver reliable one‑way flow control in demanding environments, from semiconductor tooling to general automation. Some AK4000 variants offer quick‑connect fittings for 8 mm tubing, such as the AK4000-F03 configuration, illustrating the family’s versatility in connection options. The AK4000 series is documented in SMC catalogs and product pages as Check Valve components within the AK line, emphasizing a compact footprint suitable for mounting on standard manifolds and in confined spaces. When selecting an AK4000 model, choose the port size to match your tubing or fitting standard (1/4, 3/8, or 1/2 inch) and the desired connection variant, noting that specific configurations are identified by the suffix in the AK4000 part number.