Typical Installation

Retrofit Installation

Testing the Unit

Backwater Valve Specifications

Access Box Specifications


Mainline Fullport Backwater Valve Specifications

Model number #4963

CAN/CSA-B181. 1-M90

Type I - intended for use in horizontal pipe runs to floor drains, building drains, sewers, holding tanks, etc.

Application Backwater valves should be used in building drainage systems whenever a risk of flooding due to sewer surcharge, back up, or failure exists.

  • Backwater valves must be installed to ensure access for inspection or maintenance.
  • Periodic inspection is important to maintain satisfactory performance of the backwater valve.
  • The building owner must maintain and keep backwater valves in proper working order.
Body, Lid, Gate, Cleanout plug
Acrylonitrile-Butadiene-Styrene (ABS) Plastic

Bolting System
Stainless steel 1/4 x 3/4
1/4 stainless steel

Gate Seal
Neoprene rubber ( Buna 50 durometer #241 )

Lid Gasket
Flat-section closed-cell gasket
Neoprene 3/16 x 3/8 (1220 RL BL x 1)

Floatation Devices
Closed-cell cross-linked polyethylene (PEX) foam
"Boltaron Polyethylene"

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