Increase Filter Run Times and Reduce Backwash Consumption
With superior air scouring and water backwash performance, the Leopold Type S and Type SL underdrains provide highly effective media cleaning for longer filter runs and lower operating costs per gallon of water filtered.
The Type S underdrain is ideal for installations requiring extended-length laterals and high combined air and water backwash rates, while the lower profile of the Type SL underdrain allows greater media depth in shallow filters.
- Uniform air and water distribution, even in extra-long lengths
- Facilitates high combined air and water backwash rates
- Standard profile of 12 in (30 cm)
- Lateral lengths of up to 96 ft (29.3 m) with center feed, and up to 48 ft (14.6 m) with end feed
- Can be designed for wall-feed applications as well as center flume, front flume, and Leopold Flat-Bottom Flume®
- Superior air and water distribution for effective backwash, giving longer filter runs and lower operating costs
- Easy handling – snaps together for quick installation
- Available in recycled materials for wastewater applications to reduce environmental impact
Setting the standard
Gravity media filtration underdrains collect filtered water during the filter run, and distribute air and water during the backwash cycle. Providing cleaner filter media means longer filter runs and higher water efficiency, more product water and less waste. This lowers your operating costs per gallon/liter of filtered water.
All Leopold underdrains deliver the superior performance that has made the Leopold underdrain the industry leader for nearly a century.
Robust underdrain design
The Leopold Type S underdrain is an HDPE underdrain, designed for strength and corrosion resistance.
Suitable for high concurrent air and water rates, extra-long laterals, and standard flume configurations, the Type S underdrain offers great design flexibility. It is ideal for installations requiring longer laterals, as well as applications using large filter media.
Efficient media cleaning
Leopold Type S underdrains promote trouble-free operation and effective media cleaning with closely spaced, non-clogging orifices for uniform air and/or water backwash.
The dual parallel lateral design and the water recovery channels, both developed by Leopold, give even air and water distribution and eliminate dead zones.
The Type S underdrain facilitates both sequential and concurrent air/water backwash, as well as water only backwash. In concurrent air/water backwash, the Type S underdrain enables high combined air/water rates due to the large air/water interface inside the lateral. The air scour rate can be adjusted from 2 to 5 scfm/ft2 (36 to 91 m/hr) and the water rate adjusted from 3 to 8 gpm/ft2 (7 to 20 m/hr) in the concurrent backwash, enabling effective collapse pulse cleaning with a wide range of media configurations.
Optimized installation processes
Proper installation is critical to lasting underdrain performance; that’s why Leopold underdrains are designed for ease of installation.
The Leopold Type S underdrain is equipped with internal baffles that can be installed to a level tolerance of ±0.25 in (6 mm). This is ideal for older installations where construction tolerances were not as rigid. Installation tolerances that are more forgiving also make for simpler installations and lower filter construction costs.
Meanwhile, the Grout-TITE® bridge prevents grout from entering the flume, so there’s no costly cleanup.
Our patented wire mesh installation process also strengthens the grout bond for improved uplift resistance.
Gain filter height with the I.M.S® media retainer
The Type S underdrain can be specified with Leopold I.M.S 1000 or 200 media retainers to eliminate the need for gravel media support. I.M.S media retainers replace up to 14 in (35 cm) of gravel, allowing additional media depth or greater vertical head for the backwash cycle.
I.M.S media retainers are available factory-installed on the Type S underdrain.
Reduce environmental impact with recycled materials
For wastewater applications, the Leopold Type S underdrain can also be supplied in recycled HDPE materials. The Type S Recycled Materials underdrain meets the same stringent tests for strength, durability, reliability, and performance as the original Type S – while reducing the carbon footprint of our manufacturing.
- Use of post-consumer recycled resins reduces greenhouse gas emissions by 71% for HDPE.
- Use of recycled plastic reduces total energy consumption by 88% for HDPE.