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Mainline Backwater Valves; the innovative, award-winning product designed to effectively solve your basement flooding and sewage backup problems.

backwater valve designA $10,000 Manning Innovation Award, sponsored by Falconbridge Ltd. was recently awarded to Mr. Gabe Coscarella, founder of Mainline Backflow Products, Inc. by the Ernest C. Manning Awards Foundation.

After working for many years as a plumbing and gas fitting contractor for the City of Edmonton, Gabe Coscarella learned just how damaging sewer backup and flooding can be to a home.  His company would go in after the sewer had backed up and install valves in an attempt to prevent the problem from happening again. After he and his crew had installed more than 200 valves per year for several years, Coscarella was certain there was a better way to stop the sewer backflow and flooding from happening in the first place.

top check backwater by MainlineOne day I he came up with an idea for a valve and drew it out on paper.  That drawing led to Coscarella becoming an award winning valve designer and the owner and president Mainline Backflow Products Inc.

When Coscarella sketched his new idea, the National Plumbing Code of Canada required homes at risk of a sewer backflow to be protected by valves on each sewer branch line in a house.  There is a wastewater line for your kitchen, each bathroom, laundry room, basement drain, etc.

The problem with this branch-line protection approach, Coscarella thought, was that the valves on each branch line was scattered around the basement and are typically covered walls, flooring and carpeting.  If a line plugged up and a cleaning snake was run through it, the cable typically caught on the valve gate and diminished its functionality.  The defect would be hard, if not possible to detect, difficult to repair due to its enclosed location, and now apt to let sewage in in the event of a backflow.  His new and innovative design was about to change the way in which buildings are protected from sewer backflows.

Instead of having a normally closed valve on each sewer branch line, the Mainline Fullport Backwater Valve installs directly on the main sewer line coming into the house, in a normally open or "fullport" position.  It was no longer important to install a valve on each valve.  A single backwater valve was installed to protect an entire building.

top check backwater valve operation diagramAdditionally, when Coscarella was inventing his valve, the National Plumbing Code of Canada didn't allow the normally closed valves on the market at the time to be installed on the main line. The code required the free flow of air between the building's drainage system and the municipal sewer line to prevent a dangerous buildup of sewer gases and a normally closed valve went violated that requirement.

Mainline's Fullport Backwater Valve, with its normally open design, allowed for the unimpeded passage of air.  His valve's venting property enabled Coscarella and Mainline to convince the industry and government regulators to change the National Plumbing Code of Canada in 1998.  For the first time, buildings could now be protected by just one normally open valve installed on the main sewer line.

The first prototype was constructed out of Plexiglas and Tupperware, but was illustrative and functional enough for Coscarella to obtain a patent on it!

He incorporated Mainline and attracted investing shareholders which allowed the company to build its first working valve.  This design was thoroughly tested by the Northern Alberta Institute of Technology in Edmonton, subjected to flushes with abrasive silica sand and improvements as needed were made.

The challenge was to build a valve that would work with raw sewage, allow for the free flow of waste water, and close quickly enough to prevent the backflow caused by a sewer backup from reaching an open drain.

The resulting valve which Mainline commenced selling in 1997 has interior flow channels that direct the normal flow of wastewater through it, helping to keep the valve gate clean.  The gate, hinged on the bottom of the valve is kept open by gravity.  The gate is fitted with small, streamlined, water impervious floats.  When the sewer starts to back up causing the water level to rise within valve, the gate starts to float and lift, being securely pushed into by the closed position by the reversed flow of water.

The valve has a 4" built in main sewer cleanout with a threaded cap, allowing cleaning sewer augers or snakes to pass over the open gate the gate or other components of the valve.  These tough injection molded ABS or PVC valves also have a transparent lid for easy visual inspection.  There are hundreds of thousands of Mainline Backwater Valves installed in buildings across North America.

In existing homes where a valve is to be fitted into the main sewer line, there must be a grade or slope of at least 2% (2' of fall per 100' of pipe) in the mainline for the valve to function properly.  If the line isn't changed to provide sufficient grade, it could cause potential problems.

The plumbing code In Alberta calls for every building has to be protected and the Mainline valve is used in about 95 per cent of the homes in western Canada.  In new homes, the company has never had a valve failure.

The Canadian Institute of Plumbing and Heating voted Mainline's valve the most innovative product of 1997, and the valve also won the institute's Ivan R. Leger Award.  The Mainline Backwater Valve was also awarded U.S. Patent # 5406972

The company's fullport valves are also making inroads in eastern Canada, although the province of Ontario has been slower in adopting the new approach in the National Plumbing Code of Canada.

Mainline also makes the "Adapt-A-Valve" which can be installed on the main line either normally open or normally closed (where code permits) for the U.S. market  which is more familiar with the normally closed configuration valve.  The fullport design valve is becoming more and more popular south in the US too and Mainline's valve sales are split almost 50/50 between the normally open and the normally closed configurations.  The company's product for the U.S., where a building's sewer system is required to be tested upon installation, can be also be fitted with a special test gate that slides into the same valve body and isolates the system for testing.

In the beginning, Mainline acquired grants from the National Research Council of Canada's Industrial Research and Assistance Program and the federal Scientific Research and Experimental Development tax credits program.  Once product was marketed, profits were able to sustain the company.

Mainline is now selling approximately 40,000 valves each year in Canada and the U.S. mostly through wholesale plumbing outlets.  The company's sales manager oversees a sales agent network that stretches across both Canada and the U.S.

Mainline, based in Edmonton, has remained lean and agile, employing a production manager who supervises five to six full time employees in the summer to assemble and ship products.  They sub-contract the injection molding of the valves in various sizes to another Edmonton company helping to provide jobs for another eight people.

Mainline is continuously creating new products and will soon be marketing an "insertable valve" to meet the needs of the plumbing industry.  They strive for 30% growth and have plans to expand sales into Australia.  Mainline's innovations are attracting attention from some of the world's biggest plumbing equipment firms.

Coscarella expressed that he believes winning the Manning Innovation Award will gain attention to Mainline and that he felt honored to have received such an award.

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Mainline Fullport Backwater Valves offer the right solution for your sewer backup problems.


Protect Your Home with a Backwater Valve

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copyright 2004 to 5/30/2024 at 7:52:49 ET,
Akron, OH, USA.
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backflow prevention links is independently owned and resells products produced and manufactured by Mainline of Canada and assumes no liability for the installation of backwater valves and related products.

Be sure to check with the plumbing authority in the municipality in which your valve is to be installed to insure that your installation is in compliance with local code, and be sure have your valve inspected by your local plumbing inspector after installation. Inspect your valve frequently; the Backwater Valve through its clear plastic housing top, and the Adapt-A-Valve, by removing the gate cassette.


Pipe end-to-end, the Adapt-A-Valve takes up 6" of run in your line and the outlet is 1-1/2" LOWER than the inlet, so in just 6" the level of the pipe at the outlet side needs to be 1-1/2" lower.

Pipe end-to-end, the Backwater Valve takes up 12" of run in your line and the outlet is 3/4" LOWER than the inlet, so in just 12" the level of the pipe at the outlet side needs to be 3/4" lower.

Depending upon the amount of slope in your line (2% minimum is required for proper operation), you may need to replace several feet of pipe downstream from the valve to average out this "loss" of fall.

NOTE: New Straight-Fit and ML-FR4 require less slope. (refer to detail pages for these products)


Mainline Valve Warranty
(in printable Adobe Acrobat .pdf file)

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