Flood-Guard operates like a check valve to seal off water backup caused by overloaded sewers. Water flows normally through the drain until the sewer begins to back up. Then the Flood-Guard float rises to seal off the drain opening until the water recedes.
For extreme, extended pressure, use the standpipe models. The 4" standpipe model is threaded to receive 1-1/2" IPS pipe. On the 3" model, the pipe is slipped through the rubber gasket before the screws are fully tightened.
Items sold by USABlueBook are intended for use only by professionals in the water and wastewater treatment industry. Many items sold by USABlueBook require supplemental training, licenses or permits for proper use and may be harmful if not used properly.