Many of the plumbing systems in residential and commercial properties around the Minneapolis and St. Paul area are fitted with a backflow preventer valve. This device prevents contaminated water in sewers or septic tanks from flowing back up the pipes and mixing with clean water. Plumbing technicians like P&D Mechanical install backflow preventer valves in areas where clean and dirty water are likely to cross paths. If you own a large boiler, a fire extinguishing system, or an irrigation system, your plumbing system likely contains a valve.


Annual Backflow Inspections and Testing

If you have a backflow valve installed, we need to provide professional backflow testing at least once a year to validate that it is working correctly. Backflow valves are crucial for preventing potentially hazardous contaminants such as bacteria and sediment from standing water in a boiler, or fertilizer and pesticides from a lawn irrigation system from making their way into your drinking water.


Valve assessments will reveal some issue we need to correct. If left unchecked, these issues can impair the valve’s ability to function, thus, increasing the probability of water contamination in your home, business, or in the neighborhood. Below is a summary of some of the most common problems we have identified.


First Check Valve Malfunctioning. The first check valve opens up at a certain water pressure level; It opens when water pressure reaches a 2.0 PSI. If it’s not working, the water pressure will have to increase to open it up.


Second Check Valve Malfunctioning. While checking the second check valve, we search for signs of backpressure. If the valve fails, contaminated water can leak past it, back into the area between checks where there is clean water.


Relief Valve Opening Too High. When water enters the relief valve, it goes into a relief valve sensing line. It enters an elastic element and builds up the pressure to compress a spring. The spring moves the relief valve disc to block the seal. Backflow preventers are designed with different PSI thresholds. The problems are that It can become too high if the relief valve disc isn’t positioned correctly. If not, it will affect the pressure and the valve.



Relief Valve Opening Too Low. The relief valve opening point can become too low when an object is restricting water flow into the relief valve stem mechanism. In most cases, scale and corrosion are what cause the problem.


Backflow Testing Services from P & D Mechanical

We can detect these and other problems during backflow testing. They require professional backflow preventer repairs to resolve the problem safely. P&D Mechanical offers complete backflow testing, repairs, and replacement for both residential and commercial properties in Minneapolis and St. Paul, Minnesota. To find out more about how our backflow testing service can help you, call us at 763-533-2218, or you can message us on our contact page.

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