APCO Surge Check Valves (CSV)

The APCO Surge Check Valve prevents critical shock conditions from occurring in installations where an Air Vacuum Valve could slam open or closed. The Surge Check Valve is bolted to the inlet of an APCO AVV Air/Vacuum Valve to provide slow closing functionality, protecting the Air/Vacuum Valve from slam. Because the pipeline media flows through the Surge Check Valve, it should be used in applications containing clean media.

The Surge Check Valve is a normally open valve so that air passes through unrestricted. When water rushes into the Surge Check Valve, the disc begins to close and reduces the rate of flow of water into the air valve. This ensures normal, gentle closing of the Air/Vacuum Valve regardless of the initial velocity, minimizing pressure surges.

As soon as the Air/Vacuum Valve is closed, pressure on both sides of the Surge Check Valve disc equalize and the disc automatically returns to its open position. The Air/Vacuum Valve does not need an incipient vacuum to open; it can open at any time the water level drops and the line pressure approaches atmospheric level. This immediately allows the full re-entry flow of air into the pipeline before a vacuum can form.