Top Check Backwater Valve
and Top Check Backwater Valve Parts

Mainline Top-check Backwater Valves in 4" PVC

These 4" PVC Top check Backwater Valves drop 1" from Inlet to Outlet

• This revolutionary new Mainline TopCheck Backwater Valve design features an automatic top suspended gate that can also be closed manually.

• The gate requires requires minimal maintenance and stays clean and ready to protect your dwelling from sewer backup events!

• The clear plastic lid also integrates a manual sewer shutoff allowing for easy manual closure if you know a backup event is likely, or you leave the dwelling

• We offer this package with Access Box, Bladder Seal and Alarm System!

This Top-Check Fullport Backwater Valve is Mainline’s newest an most advanced automatic backwater valve.  The top-suspended gate is up and out of the normal flow of waste so stays clean and ready to protect. This is a normally-open gate automatic backwater valve design.

A unique design feature in the clear polycarbonate inspection lid allows the owner to easily twist a red shut off to manually close the valve gate

The clear plastic lid allows for easy visual inspection and a removable black plastic lid for cleaning or main sewer line snaking / rodding.

The Schedule 40 PVC (poly vinyl chloride) 4" DWV valve body is sturdy and durable.

Black ABS Access Box with removable access panel Included!

Bladder Seal Included!

Seals the dwelling against groundwater flooding through the box.

Seals against insects / bugs from entering dwelling through the box.

Ensures nice clean access to your TopCheck Backwater Valve free of concrete, gravel, sand, mud and water once installed over the access box.

Protects against radon gas from entering your dwelling and easily integrates with any existing vapor barrier system.

Top Check Backwater Valve Alarm System Included!

This is an integrated backwater valve flood alarm for the Mainline Top-Check Backwater Valve, powered by a standard 9V battery.

It can be easily installed by simply inserting an included magnet into a factory-provided slot in the Top Check Backwater gate, installing an electromagnetic sensor on the outside rim of the clear plastic cover adjacent to the magnet, and connecting the included wiring he Alarm Box.

The box emits a loud, shrill tone (similar to that of a smoke alarm) to alert you  when your Backwater Valve is in active and protecting you from a sewer line backup.

VIEW Top-Check Alarm brochure here

Patented in USA # 5406972
Patented in Canada # 2114602
Other patents pending
Made in Canada
ASME A112.14.1-2003(R17)
CSA B181.1-02 and CSA B181.2-2018
UPC Compliant
National Plumbing Code of Canada Compliant
International Plumbing Code (IPC) Compliant

This product has been tested by an IAPMO R&T recognized laboratory. This recognition has been granted based upon the laboratory's compliance to the applicable requirements of ISO/IEC 17025.

View the ToCheck Backwater Valve brochure here