We’re not so far from Thanksgiving and we know that families will be coming to town and lots of food will be consumed. The last issue that you want to come up with having backflow in your home. Deer Valley is here to help you prevent backflow during the holidays! We are here for all of your plumbing needs so just sit back and let us tell you about backflow preventers.
The Different Types & How They Work
There are multiple types of backflow preventers, the three most common being the pressure vacuum breaker (PVB), the reduced pressure zone (RPZ), and the double check assembly (DCA). These are all installed in the water system immediately after the isolation valve.
Pressure Vacuum Breaker
Pressure vacuum breaker assemblies (PVB) are the most common, inexpensive type of whole-system backflow preventer. It consists of an inlet shutoff valve at the bottom, a single valve body consisting of a pressure vacuum breaker, check valve, and two test cocks, and an outlet shutoff valve. As well as being inexpensive, PVBs are relatively simple in design, and are easy to install, maintain and repair. Some pressure vacuum breakers also offer built-in freeze protection; however, this only protects the PVB assembly. Inlet and outlet pipes can still freeze if the system isn’t properly winterized.
Double Check Valves
Double check valves (DCV, also called double check assemblies or DCA) are a good choice for underground or indoor installations. A DCA consists of an inlet shutoff valve, two independently operating spring-loaded check valves (usually inside a single valve body), four test cocks, and an outlet shutoff valve.
The DCA is the most common type of approved backflow prevention device for use in underground or in-line installations. Some areas do require above-ground installation, so check with local authorities before installing below ground. It is possible to build a double check valve assembly from new components, but this is not the best option as there is a high risk of built assemblies not meeting local code. A better option, for convenience, cost-effectiveness, and coding restrictions, is to purchase a pre-assembled double check valve assembly.
Reduced Pressure Zone Assembly
Reduced pressure zone assemblies (RPZ), also sometimes called a reduced pressure principle assembly, is the most complex and expensive backflow preventer. However, when working properly, RPZs are the most secure and reliable of all backflow prevention devices. A reduced pressure zone assembly consists of an inlet shutoff valve, two independently operating spring-loaded check valves separated by a pressure differential relief valve, four test cocks, and an outlet shutoff valve.
Reduced pressure zone assemblies come in a variety of configurations. Choose an “inline” or “straight” configuration for installation underground. For above-ground installation, consider an “n” configuration assembly for a very small footprint.
Contact Deer Valley
If you need help with testing, caging, installation, repair or replacement of your backflow preventers, Deer Valley Plumbing has your back. Give us a call at 602.832.8418 or visit our Contact Us page!