Mainline Backwater Valve

The Mainline Fullport Backwater Valve Model #'4963' is now one of the most trusted and accepted backwater valves in construction today. Many of the new homes in Canada get a Mainline valve during construction because it provides automatic sewer protection and is more user friendly for both the contractor and building owner.

The Mainline Fullport Backwater Valve installed on the main building drain allows for the free circulation of air and will protect the entire building from backflow with just the one valve. The location of the valve, just inside the footing; makes it easy and convenient for the building owner to find for inspection and servicing, the valve also has a built-in sewer cleanout on it eliminating the need for a building sewer cleanout. Plumbing contractors and municipalities using the Mainline Fullport Backwater Valves quickly see the advantages of Main-building drain protection over the old fashioned 'branch' protection.

Today there are close to 200,000 Mainline Valves in operation across Canada and the United States. The news and success of the valve has reached the United Kingdom and Australia with sales starting to flow to these countries.

For more information contact Mainline Backflow Products.


Advantages of using the Mainline Fullport Backwater Valve

The Mainline Fullport Backwater Valve is installed in the main-building drain, because its fullport design allows venting of the municipal sewer through the building. The design also allows unobstructed sewage flow and automatic closure of the gate upon reversal of flow (sewer backup) protecting the entire building from backflow.

• The entire plumbing system is protected from municipal sewer backup with just one conveniently located backwater valve at the point where the building drainsewer exits the building. This offers EASY HOMEOWNER ACCESS

• The Mainline Fullport Backwater Valve has a built-in main sewer cleanout in the valve for the rodding of the sewer.

• Since the Mainline Fullport backwater Valve is a "normally open" backwater valve, it allows unobstructed sewage flow, which in turn prevents sewage buildup in the valve's body.

• The "normally open" design allows cleaning tools to pass through the body without getting hooked on the gate when retrieving the cable (this prevents the gate from being destroyed).

• By installing the valve in the main-building drain it eliminates the need for branchline backwater valves, cleanout assemblies, and also saves in groundwork labor and extra piping when, trying to utilize one branchline bwv to protect extra fixture drains.

• Ensures that entire building is protected from backflow, where branches are often missed and left unprotected, when using branchline protection

• If additional fixtures or branches are added to the system they are automatically protected from backflow


Disadvantages of Traditional, Normally Closed Backwater Valves

• Normally closed BWV's are installed only on the branchlines of the building drain because they don't allow a free circulation of air from the stack to the municipal sewer system.

• Since the BWV's are installed on the branch of the building drain, the valves (typically situated in hallways, underneath cabinets, under furnaces, etc. and usually covered by flooring) are difficult to locate and access for servicing.

• Often branches are missed and left unprotected by inspectors and plumbers upon rough-in

• Branchline BWV's are "normally closed", and therefore require the flow of sewage to push open the gate. This results in an accumulation of solids on the gate and piping leading up to the inlet side of the valve, and will affect the reliability when a backsurge of the municipal sewer occurs.

• Interfere with buildings venting system.

• When cleaning tools are run through "normally closed" BWV's, the gate is destroyed upon retrieving the cable.

• Installation on the branchline of the building drain usually requires more than one BWV, leaving the homeowner with multiple inconveniently located BWV's to service.

• Still requires Main-sewer cleanout assembly.

• Labor intensive

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