Typical Installation

Retrofit Installation

Testing the Unit

Backwater Valve Specifications

Access Box Specifications

Maintenance

Installation of Backwater Valve

Prior To Installation

  • Inspect unit through cleanout
  • Check o-rings
  • Make sure flotation devices are in place (one on each side of gate)
  • Check the gate and ensure it moves freely.

Installation
  • Allow maximum grade when possible - 4% or higher
  • NOTE: min. grade must be at least 2% - 1/4 inch per foot
  • Check grade with level by placing it on the bolts
  • See arrows for direction of flow
  • Do not install any branches within 2 feet of inlet side of valve. This will ensure laminar flow through valve body (as there is no control of fitting layouts, in retrofit installations this rule may be waived by the enforcing authority)
  • Care should be taken when solvent welding pipe into valve. Ensure solvent does not enter the body as it will affect the valve's function
  • Re-inspection of unit-remove sand, gravel, dirt or any other debris which may have entered the body and and hinge area upon installation
  • Tighten cleanout
  • Install Mainline Access Box
WARNING
  • Improper installation may result in valve failure
  • Follow installation procedures carefully, with special care and attention to be taken when retrofitting valve into existing systems
  • Do not install if proper grade cannot be achieved


Home Why a Mainline Valve How it Works Installation Links Contact Us Privacy Policy Mainline Backflow Products Canadian Home Builders' Association Mechanical Contractors Association of Alberta