How the Size of a Backflow Preventer Affects Performance
A great number of factors impact the success and effectiveness of plumbing prevention equipment. Read on to learn how the size of a backflow preventer affects performance.
Flow Rate Considerations
The main impact of backflow preventer size on prevention performance concerns flow rate. Basically, flow rate measures gallons of moving fluids per minute, or GPM. Large plumbing infrastructure can support high quantities of water and typically features fast flow rates. It's important to select a backflow preventer size that supports your existing system’s GPM rating. An undersized prevention device cannot effectively manage backflow, while oversized preventers can physically damage water lines. Most residential buildings have systems with 4-80 GPM ratings. Conversely, commercial properties often require support for 100 GPM or more.
Water pressure Considerations
Water pressure is very important in fire sprinkler systems. The pressure must be constant and it must be reliable, in the case of a fire. Tall buildings require a lot of water pressure, to pump water up to the top floor. Very large buildings usually have a backflow preventer that is 8 inch or larger in diameter, and often they need several backflow preventers in the same building. Likewise, in very flat areas, like the great plains, it can be harder to build water pressure, so larger valves are needed.
Conversely, small office buildings, townhomes, churches, and other small structures typically can use smaller diameter backflow preventers. These types of buildings usually use between 2 inch and 4 inch backflow preventers.
Residential backflow preventers are even smaller. These are different than what we carry at Backflow Direct.
If you are installing a backflow preventer on a new building or home, a specifier may tell you the pipe size and flow rate that is required. This will help you determine the inlet connection size of the valve. You can find the flow rate of the valve in the product spec sheet. If you’re replacing an older backflow preventer, you will also need to know the flow rate and inlet connection size.
You can clearly see that the size of a backflow preventer significantly affects the device's performance. Luckily, our friendly team at Backflow Direct is here to help you find the proper Deringer backflow preventer valve and related prevention equipment for your system. Contact us today to learn more about our different backflow preventers and plumbing solutions!