At the front of the dams is drain port, this port drains away any water which may seep under the gate through the inlet side of the valve

Upon a slow reversal flow, water rises in the body and the gate starts to float (lift). Once the gate starts to lift the water flow in turn pushes the gate into the gate position.

Depending on how your land is used, the type of device that you need will be defined by the backflow risk of your property;

However, if the pressure in the water main goes lower than the pressure in your plumbing supply, backflow can occur. The flow changes direction and may cause waste, pollutants and other hazardous materials to enter into your water supply. Your life-giving liquid then presents a hazard to your health. Changes in pressure can happen if the water main bursts or there’s a high demand, such as during fire fighting operations.

The Mainline #4963 Full-Port Backwater Valve is the ‘flagship’ of the company. Established in 1997, this valve has revolutionized sewer protection across North America with its patented ‘normally open’ gate design. This valve is typically installed in homes or buildings that have basements, cellars, crawl spaces or area that are accessible for servicing. The normally open gate allows the sewer system to ‘vent’ any gases that may be causes by positive or negative pressures in the sewer line. The 4963 has a ‘Clear View’ top that makes inspection of the valve quick and simple for the building owner or plumber! As well, the 4963 comes with an integral clean-out for rodding the sewer lateral. Should rodding from the stack be necessary, the snake can easily pass over the open gate and be retracted with out doing any harm to the components.

You are responsible for maintaining the backflow prevention devices on your property since you own them. Testable devices require checking at commissioning, after maintenance or at least annually. Only licensed plumbing contractors may test these devices. They must give you the results within five days after the test. Otherwise, there’s a penalty of $1,000. If you do not maintain the devices, you may receive a non-compliance notice.

At the bottom of the valve you will notice dams, the gate in the open position rests on these dams preventing any flow from circling back from the outlet side of the gate and penetrating back into the hinge area,

The built-in sewer clean out is downstream of the gate, a sewer tape will not catch on the gate when feeding or retrieving the cable

The #2013 Access Box is a very useful accessory to the 4963 valve. Its dimensions of: length 20 in; width of 12.5 in; and height of 16 in make accessing the 4963 for servicing a very easy task!

On models fitted with closed cell polyethylene floats, check the condition of floats and replace as necessary. * Note: these floats are located on both sides of the gate and are protected from sewage contamination by the sidewalls of the gate and body (long-life cycle, impervious to sewage). CSA certified floats.

The water in your everyday plumbing typically flows in one direction. From a potable supply through the fixtures in your building, such as faucets and showers, down the drain and to the sewer system. Adequate water pressure usually maintains this flow. This is so that you can turn on your faucet and enjoy a safe and refreshing drink.

Upon a quick reversal: The gate is fitted with 45 degree angles on the front which act as wings, upon quick reversal action water is diverted into the wing area through the flow channels. Water then pushes up on the 45 degree angles causing the gate to quickly close.

Backflow prevention devices are necessary to keep you and the other occupants of your property safe and healthy. Don’t avoid their installation just to save money or because it’s inconvenient. You risk the health and safety of people as well as expose yourself to fines and disconnection of water service.

Backwater valves are mechanical devices sitting in a sewage environment, and regular inspections are required. To ensure the satisfactory performance of the backwater valve follow the procedures listed below.

The Water Services Act 2012 and Water Services Regulations 2013 mandate the installation of backflow prevention devices. This is to protect the public from the health problems or death caused by backflow incidents. You may receive notice to install these devices at plumbing connections within your property boundary. If you do not comply, you may be fined up to $5,000 plus $500 per day, or have your water services restricted or disconnected.

Backflow prevention devices can only a licensed plumbing contractor. The contractor installs the device inside your property boundary on your side of the water connection. The device must be out in the open. It cannot be put in a pit, chamber, or underground. After installation, the contractor must register the device.

Gate is fitted with closed cell polyethylene floats, this flotation material is impervious to sewage and will not become water logged (gate design locks floats in place)

A simple way to prevent backflow is to add an air gap. This is a vertical space between where the water comes from, such as a valve, and where water can collect, such as a sink. In more complex systems or when there’s a greater risk of contaminants entering the water supply. A physical backflow prevention device is needed at each connection to the drinking water supply. Specific situations also require the device:

Your property receives a risk rating when the building application is approved. Descriptions in the Land Use Code are used for assigning the risk level, based on what you plan on doing in the property. For example, if your property is either used for industrial waste process or has unknown uses, it receives a high-risk rating. Your plumbing contractor can advise you on the minimum type of backflow device needed in your system based on the rating.