Irua - Swing Check Valves

To avoid slam is essential that the counterweight closes the valve before a flow reversal occurs. That Slam is what causes the “Water Hammer” in piping systems. The cushion cylinder cannot retard the valve closure and will minimize the slamming tendency when the valve closes too quickly due to its own counterweight. The counterweight requires an opening force that diminishes as the valve opens and produces the maximum closing force at the seated position where it is most needed. The pressure drop is therefore minimized. This type of Swing Check valve is designed to produce full pipeline flow area at only 25 to 30 degrees opening. In response to a high demand the disc continues to lift up to a maximum of 60 degrees while other types of swing check valves as the Slantered type cannot absorb this high demand conditions.