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Mainline Fullport Backwater Valve

The Mainline Fullport Backwater Valve is a “normally-open” backwater valve.

• The valves "normally-open" design allows un-restricted sewage flow from inlet to outlet.
• This "normally-open" design is what sets this valve apart from the industry standard flapper valve
• Clear transparent cover allows easy visual inspection of the valve
• Built-in flow channels on the gate and body, direct sewage out of the valve. These flow channels prevent sewage from flowing beneath the gate, where it may effect the mechanics of the valve.
• Upon a quick reversal sewer backsurge, flow is diverted to the gates 45-degree wings (incorporated on the sides of the gate) – this causes an upward lifting action of the gate. Once the lift occurs, the reversal flow of water quickly slams the gate into the closed position, isolating the entire plumbing system from backflow.
• Upon a slow reversal backsurge, the gate is fitted with certified flotation devices that initiate the lifting (floating) of the gate. The reversal flow of water then pushes the gate closed, isolating the system.
• As part of the design a BUILT-In CLEANOUT feature is incorporated downstream of the gate, for the rodding (snaking)of the building drain-sewer
• So not only is this a "normally-open" backwater valve with a clear cover, but also a cleanout for your building-sewer.

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

• Allow maximum grade when possible
• NOTE: min. grade must be at least 2% - ¼ inch per foot
• Check grade with level by placing it on the bolts
• See arrows for direction of flow
• DO NOT install any fittings 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 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 hinge area upon installation
• Tighten cleanout
• Install Mainline Access Box (PE2013 or equivalent)

• Failures may occur due to back grade on valves. In order to achieve grade in retrofit installations, an installer must expose approximately 4-5 feet of piping. Often sewers are at a minimum, flat, or back grading. Since there is ¾ of an inch difference in height from inlet to outlet on your Mainline valve, it may be necessary to adjust the grade on the piping leading up to the valve, to achieve required grade on the backwater valve.
• In retrofit installations, always run and test all fixtures to ensure each fixture runs through the backwater valve, and nothing remains unprotected
• Check that the sewer is unrestricted (roots, blockages, etc.) downstream of valve
• Ensure weeping tiles (French drains) tie in downstream of valve
• Warning: Improper installation may result in valve failure.

Optional Access Box for Mainline Fullport Backwater Valve 4963

• Intended to be used as an access opening for the Mailnline Fullport Backwater Valve Model #4963. Add PAGE # 22 (May be used for other access applications such as cleanouts, irrigation, etc.)
• Reading Plate: Maintenance instructions for building owner (Reading plate may be customized for distributor)
• Body and Lid - High-density polyethylene (plastic). Bolts - Zinc coated ¼ x 1½ in.
• Weight approximately 5 lbs.
• 16" H x 12.5" W x 20" L