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The HDPE Rainstopper is a patented manhole insert designed to reduce inflow in your municipality’s sanitary sewer system. It also reduces the inflow of street level contaminants, while simultaneously controlling the escape of undesirable sewage odor and minimizing traffic related manhole noise and cover displacement. The

insert is manufactured in the USA to precise, custom specifications from extremely durable HDPE plastic. Its unique design allows for the venting of sewer gases through a non-mechanical device, reducing maintenance costs by eliminating moving parts. Weighing only 2 pounds, it can easily be installed by a single person. No engineering necessary.


Accurate frame and cover measurements are absolutely critical for the successful elimination of inflow. While carefully following the instructions included on the Rainstopper Measurement Worksheet (PDF 244 KB) measure and record the physical dimensions for each unique manhole  frame and cover. Enter the desired quality for each measurement configuration. Do not hesitate to contact us if you have questions or concerns.


Long term exposure to UV rays can deteriorate the gasket, so care should be taken to protect the stored units prior to installation. Manufacturer recommends either leaving polyethylene shrink wrapped units on pallets if stored outside or storing unpackaged units in an area protected from direct sunlight.


To install the Rainstopper, remove the manhole lid. Clean all dirt and debris from manhole frame. Seat Rainstopper in manhole frame rim. Replace manhole lid. Ensure lid is flush with frame to alleviate tripping hazard. Once installed, maintenance is not required.


Limited one-year replacement warranty: If this insert is defective in materials or workmanship within one year of purchase, it will be replaced free of charge by Rainstopper, if not damaged through mishandling, accident, or abnormal use. This warranty excludes all consequential damages in those states where such exclusion is allowed.


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