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Depending on your application and the duration the project will require additional ground water run-off inlet protection FleXstorm has you covered. As the leading storm water control product these stainless steel filter housings stand up to the elements and continous work for years. 

Flexstorm Pure Inlet Filter Logo
FleXstorm Catch-IT inlet filters Logo
FleXstorm Catch-IT LITE logo

The FLEXSTORM PURE system is the preferred Catch Basin Insert for permanent inlet protection and storm water runoff control. Constructed of versatile stainless steel, FLEXSTORM PURE Catch Basin Inserts will fit any drainage structure and are available with site-specific filter bags providing various levels of filtration. Whether you’re the specifier or the user, it’s clear to see how FLEXSTORM PURE Catch Basin inserts outperform the competition.

PURE Benefits

  • Stainless Steel filter framing is custom configured to fit perfectly into any drainage structure, whether a standard design or obstructed inlet opening
  • Filters work below grade with an ultimate bypass allowing inlet area to drain with a full bag
  • Multiple Filter Bags are available targeting site specific removal of trash, litter, leaves, or small particles, oil and grease
  • Filtered Flow Rates and Ultimate Bypass Rates are designed to meet your specific Catch Basin requirements.
  • Units install in seconds and are easily maintained with the FLEXSTORM Universal Removal Tool (no heavy machinery required)

What are they made out of? 

The FLEXSTORM Inlet Filter system is comprised of a corrosion resistant steel frame and a replaceable geotextile sediment bag attached to the frame with a stainless steel locking band. The sediment bag hangs suspended from the rigid frame at a distance below the grate that shall allow full water flow into the drainage structure if the bag is completely filled with sediment.

Flexstorm Pure Square inlet filter
Flexstorm inlet filter in a square drain
Flexstorm inlet filter holding debris in a circular road drain
Schematic of a circular drain with Flexstorm Pure inlet filter

The Inlet Filter frame includes lifting handles in addition to the standard overflow feature. A Removal Tool engages the lifting bars or handles to allow manual removal of the assembly without machine assistance. The frame suspension system on most rectangular designs is adjustable in ½” increments up to 5” per side should the casting or drainage structure have imperfections.

rectangular frame for Flexstorm Pure inlet filter
metal Flexstorm frame
Flexstorm inlet filter being lifted out of a grate with a lifting tool


PURE Inlet Filters for permanent inlet protection: The FLEXSTORM PURE framing is comprised of 304 stainless steel with a 25 year life rating. Multiple filter bags are available: FX, FX+, PC, PC+, LL and others. The Post Construction “PC+” is the design standard consisting of the “FX” Woven Polypropylene sediment bag lined with Adsorb-it filter fabric, which is made from recycled polyester fibers. The “PC+” includes a replaceable hydrocarbon skimmer pouch strapped to the bottom of the bag for advanced TPH removal.

Flexstorm Pure filters with PCP hydrocarbon absorbent bags installed

Flexstorm Filters in Action