1.5" Foam Bridge

This compressible foam seal wrapped in a polyethylene sleeve expands instantly when it exits the bottom of the drive casing to provide positive placement of a barrier that prevents any solids from entering the screened area. It provides a positive temporary barrier when used above the water table in conjunction with granular Bentonite, pellets or chips. Expanding foam bridge on a 6" piece of riser; male X female astm flush thread