Leopold Type XA underdrain

Overview Specifications Solutions Documentation & Tools
  • Leopold Type XA filter underdrain
  • Leopold Type XA dual parallel lateral underdrain
  • Patented grout pocket for superior uplift resistance
  • Type XA underdrain with I.M.S 200 media retainer


Product Features
  • Superior uplift resistance – withstands uplift pressures up to 65 psi (4.5 bar)
  • Low profile of 8.25 in (21 cm)
  • Lateral lengths up to 60 ft (18.3 m) with center feed, and up to 32 ft (9.75 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
  • Quick and easy installation with snap-together assembly and simple leveling

In a gravity media filtration system, 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 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.

Optimum media cleaning

The Type XA underdrain delivers superior backwash air and water distribution with patented interior baffles and dual water recovery channels. The innovative dual parallel lateral design and the water recovery channels, both developed by Leopold, deliver backwash water with less than +/-5% maldistribution and eliminate dead zones.

Air scour capabilities provide higher shear forces and cleaner media than water backwash alone, with less water wasted. Meanwhile, air flow adjustability allows for more control and saves energy and water. With the Type XA underdrain, the air scour rate can be adjusted from 2 to 5 scfm/ft2. (36 to 91 m/hr), enabling collapse pulse cleaning during concurrent air/water backwash.

Superior hold-down performance

The Type XA underdrain also delivers superior uplift resistance (also known as hold-down performance) without the need for expensive mechanical anchors. The key is Xylem’s patented grout pocket and wire mesh installation, which ensure that the Type XA underdrain will not lift from the filter floor, even if internal operating pressures reach 65 psi (4.5 bar).

Quick and easy installation

The Type XA underdrain’s lateral lengths and compatibility with standard flume layout options provide design versatility for new installations and retrofits.

Specially engineered features enable simple construction or retrofits without compromising quality, reliability, or performance. Snap-on/off handles allow two workers to easily maneuver blocks into position, and the blocks snap together with a bell and spigot seal, expediting installation.

In addition, the Grout-TITE® bridge prevents grout from entering the flume, so there’s no costly cleanup.

Save on filter height

The Type XA underdrain can be specified with Leopold I.M.S® 200 or 1000 media retainers, which come factory-installed to save time at installation. I.M.S media retainers replace up to 14 inches (35 cm) of gravel to allow for deeper media or higher backwash driving head without requiring more vertical space.




*Depending on lateral length 



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