Waste lines from a sewage ejector or sump pump use a check valve to stop wastewater from flowing back into the basin. When these valves shut, they can make a thud loud enough to be heard throughout the house.
Everbilt 1.25 in. and 1.5 in. ABS InLine Sump Pump Check
For sump pump applications the THD1020 can be used with any 1.25 in. or 1.5 in. sump pump. The THD1020 features 1.25 in. or 1.5 in. combination rubber adapters and the industry's most durable check valve
The Flotec Sump Pump Inline Check signed to help prevent pumped water from flowing back into the basin. This check valve nnection of 11/4 in. nnection that can be 11/4 in. or 11/2 in. Easy to install, nstructed of rubber.