Underdrains collect filtered water during the filter run, and distribute air and water during the backwash cycle. Providing cleaner filters mean longer filter runs and higher water efficiency, more product water, and less waste. This lowers your operating costs per gallon or liter of filtered water. All Leopold underdrains deliver the superior performance that has made the Leopold underdrain the industry leader.
The Leopold Type SL® underdrain features a low profile of 8” (20cm), making it the perfect choice for shallow filters.
The dual parallel lateral design and the water recovery channels, both developed by Leopold, give even distribution with less than +/-5% maldistribution and no dead zones.
The Type SL underdrain can be specified with Leopold I.M.S.® 1000 or 200 media retainers and factory-installed on the Type SL underdrain to save time at installation. The I.M.S. media retainers replace up to 14 inches (36 cm) of gravel media support allowing for the same media depth in less vertical space or longer air/water backwash.
The air flow adjustability allows for more control and saves energy and water. Air scour rate can be adjusted from 2 to 5 scfm/sq.ft. (0.6 to 1.5 m/min), enabling collapse pulse cleaning during concurrent air/water backwash with various media configurations. Air scour provides higher shear forces and cleaner media, with less wastewater generation.
The Type SL underdrain is also equipped with internal baffles that can be installed to a level tolerance of ±1/4 inch. This is ideal for older installations, where construction tolerances aren't as rigid. Installation tolerances that are more forgiving also make for simpler installations and lower filter construction costs.
In addition, the Grout-Tite® Bridge prevents grout from entering the flume, so there's no costly cleanup.