Fire Sprinkler Backflow Prevention 101
Have you ever wondered how drinking water is separated from the water in fire sprinkler systems and pipes? The difference is potable (treated, drinking quality) vs. non-potable (untreated, not fit for drinking) water, and backflow preventers are responsible for keeping potable water clean and free of contaminants.
The purpose of a backflow prevention device is to prevent the water utilized in a building’s water systems from backing up and entering into drinking water. This can include the domestic water system, the irrigation system, and the fire sprinkler system. All water companies in the State of Texas require that backflow preventers be tested, regularly inspected, and maintained by certified professionals to ensure they are reliable and functioning properly.
Types of Backflow Preventers for Fire Sprinkler Systems
There are many types of backflow preventers and each has specific applications. While the testing for each type generally remains the same, the most common assemblies for commercial fire protection systems are:
- Reduced Pressure Zones (RPZ):Primarily intended for plumbing and other internal systems, RPZs are the most complex and reliable backflow preventers. These devices consist of a shutoff valve, two spring-loaded check valves separated by a pressure differential relief valve, four test cocks, and an outlet shutoff valve.
- Double Check Valves (DCV): As the most common type of approved backflow prevention device, DCVs consist 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. DCVs are specifically designed to prevent backflow in fire sprinkler systems.
Backflow Testing, Maintenance, and Inspections
Scheduled testing of backflow assemblies is essential for State of Texas code compliance and commercial building safety. A routine backflow test consists of attempting to remove water from a backflow assembly. While the frequency of testing varies between jurisdictions, it is expected to be tested annually at a minimum. These system tests are critical to ensure potable water is safe to drink.
Due to the inherent risk of contaminated water, a backflow assembly only delivers pass or fail results – there is no middle ground. If any water escapes the backflow assembly, it fails. If a device fails the test, it should be repaired or replaced immediately. Solutions for failed backflow assemblies can vary in scope and costs, but can be as simple as replacing parts.
To have an FireTron, Inc. fire professional conduct inspection and testing services on your backflow assembly call 1(800)-575-TRON or request a backflow service or inspection on our site.