A piston or ball check valve uses a cushioned closure element, either a piston guided within a cylindrical bore or a free floating ball, that lifts off its seat under forward flow and returns to seal the moment flow stops. The piston design incorporates a dashpot action that slows the final stage of closure, cushioning the impact and reducing wear on the seat over repeated cycles. Ball check valves, by contrast, rely on the ball’s own weight and buoyancy in the fluid to reseat quickly, making them well suited to viscous or dirty service where a hinged disc might stick or foul.

Common Applications

• Metering and dosing pump discharge lines
• Viscous fluid service where debris could foul a hinged disc
• Small bore instrumentation and chemical injection lines
• Applications requiring cushioned, low noise closure