Measuring and Installation Procedures:

  1. Remove the Manhole cover.
  2. Clean the Manhole rim flange area of dirt and debris to insure accurate measurement.
  3. Locate Manhole frame Inside Diameter (ID) and measure across ID with a minimum of two dimensional readings for accuracy-record the smallest measurement to the nearest 1/8".
  4.  Locate Manhole Outside Diameter (OD) and measure across OD with a minimum of two dimensional readings for accuracy-record the smallest measurement to the nearest 1/8".
  5.  Install Inflow Dish and replace Manhole cover.

For additional assistance contact USSI
at 941-926-2646.


Inflow Dish Body:
The inflow dish body shall be manufactured from high density polyethylene material, comply with UL Standard, 94-HB, and meet all associated ASTM specifications related to Prime HDPE 250. Dish thickness shall be a uniform 1/8" thick or greater. Inflow dish shall have a minimum depth at the 90 degree vertical point of 3.8 inches and a minimum depth of 5 inches at the center point. Inflow dish body to be fabricated with molded ribbing members in bowl area for structural integrity. Inflow dish to have smooth radius molded edges for additional strength and prevention of cracking. Inflow dish to have manufacture date (Month & Year) permanently molded in dish body for future warranty identification.

Gasket Seal:
The gasket seal shall be made of closed cell neoprene material and have a pressure sensitive adhesive on one side for adhering to inflow dish body, seating rim. Gasket to be 1/2" wide and shall have a minimum thickness of 1/8".

Lift strap:
The Lift strap shall be made from a woven polypropylene material, securely adhered to the inflow body interior, with a corrosion resistant fastener assembly.

For proper abatement results, the inflow dish, when installed, must seat fully flush within the manhole frame rim seat area. Frame must be cleaned of all dirt and debris prior to installation.

USSI recommends clients inspect inflow dish gasket seal on an annual basis. To ensure proper abatement performance, replacement of worn or missing gaskets may be required.

Five-year warranty on manhole inflow dishes standard. Manufacture date molded into inflow dish body. Gasket seal not included. Replacement gasket seals are available from USSI.

The Inflow Defender™, manhole inflow dish, shall be furnished exclusively by USSI, LLC Venice, Florida.

If you are a Florida Utility please contact us directly for Piggyback Contract Pricing


Quote Request

Inflow Defender®

The USSI Manhole Inflow Defender® (Inflow Dish) was designed to significantly abate rainfall "Inflow" from entering the sanitary sewer system through the manhole cover and upper frame area. The Inflow dish shall withstand all gases associated with waste water collection systems. To ensure a proper fit, inflow dishes are manufactured to specific measurements provided by the client. Please see USSI Inflow Defender® Dish Measuring and Installation procedures.