The Titan KCV Klunkless Check Valves are installed on sump pump discharge pipes to keep water from returning to the sump pit when the pump stops. They also keep flooding water from entering the building through the discharge pipe. 

Features:

• Fits pipe from 1-1/4" to 1-1/2" in diameter
• Air tight chamber prevents water entry
• Includes stainless steel hose clamp
• No gluing required
• Not for use on ejector pumps

When the pump is running, the flapper in the check valve opens and lets the water out. When the pump stops, the water above the check valve rushes back down and automatically slams the flapper closed. While this keeps the water from re-entering the sump pit, it also makes a loud and annoying clunking noise.
The Klunkless Check Valve has a large silencing air chamber that absorbs the sound of the returning water and reduces the noise when the pump stops. You won't be awakened on rainy nights by a clunking noise every time the sump pump stops.    The Titan KCV Klunkless Check Valve is also known as the Basement Watchdog, PHCC Pro Series, and Glentronics Klunkless Check Valve.