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Flow-through protection systems are those systems that do not have fire department pumper connections. They are constructed of approved potable water piping and materials to which sprinkler heads are attached. The system termi- nates at a connection to a toilet or other plumb- ing fixture to prevent the water from becoming stagnant. Combination protection systems also do not have fire department pumper connections and are constructed of approved potable water piping and materials that serve both the fire sprinkler system and the consumer’s potable water system. Both of the above two systems do not require backflow preventers because they are connected directly to the potable water and the inherently designed to potable water standards. Closed fire protection systems are separated from the potable water system by the minimum use of a Double Check Valve Assembly (DCVA) as long as no chemicals are used and a Reduced Pressure Backflow Assembly (RPBA) if chemicals are used. Closed system may have a fire depart- ment pumper connection. Note: 1. The water purveyor must be consulted for proper backflow prevention requirements. 2. It is important to have the system engineered hydraulically. The NFPA standards 13 and/or 13D must be considered when designing the fire system. 3. Flow and pressure may not be adequate for fire protection. 4. A plumbing and/or fire permit may be required prior to starting the project. 5. A system is less expensive to install at initial house construction. 6. Some water purveyor’s requirements may be more stringent than others – consult you local purveyor for requirements. Residential Fire Sprinkler Systems and Backflow Prevention © 2001 R 3/30/02 [Brochure For further information contact your local water purveyor or the PNWS/AWWA Cross-Connection Control Committee through the PNWS office at (877) 767-2992 American Water Works Association Pacific Northwest Section ---PAGE BREAK--- Residential Fire Sprinkler Systems Residential fire sprinklers are in greater demand today than ever before. Personal fire safety is such a trend that in many areas ordinances or resolutions require fire sprinklers on all new residential construction. Residential fire sprinkler systems help save lives and reduce property damage. However, from the water purveyor’s point of view, the residential fire sprinkler system presents a potential pollutant and/or con- taminant source to the potable water system from cross-connections. Both homeowners and the public may be exposed to health hazards from residential fire sprinkler systems. Such hazards include stagnant water, non-potable piping, heterotrophic bacteria, and chemicals. Therefore these systems must be evaluated for health and system hazards. The following minimal information should be considered in the selection of backflow protection on residential fire sprinkler systems. Residential fire sprinkler systems are categorized as flow-through, combination, and closed fire protection systems. Each of these systems has their advantages and disadvantages. It should also be noted that what the local fire departments, local administrative authorities and water purveyors allow will determine which of these systems can be found in any particular jurisdiction. It is imperative that the water purveyor, local administrative authority, fire department, and other agencies coordinate their efforts in the design and operation of these systems. Flow-Through Fire Protection Systems Advantages 1. Contains no standing or stagnant water. 2. No backflow protection is required. 3. Usually requires a single meter. Disadvantages 1. Service line, meter and plumbing system must be designed hydraulically to supply both domestic and fire flow requirements. Sprinkler system must have connection at the end to a clothes washer, dishwasher, toilet or other fixture to prevent water from becoming stagnant. Combination Protection Systems Advantages 1. Contains no standing or stagnant water. 2. No backflow protection is required. 3. Usually requires a single meter. 4. Water use throughout the potable water system eliminates need for water use at the end of the system. Disadvantages The service line, meter and plumbing system must be designed hydraulically to supply both domestic and fire flow requirements. Closed Fire Protection Systems Advantages 1. Installing a separately metered service line may be cheaper than upgrading an existing service. 2. A fire service rate is usually cheaper than a residential service rate. Disadvantages 1. Approved backflow preventers must be installed, thereby increasing the homeowner’s cost by its initial installation, and thereafter for annual testing and maintenance. 2. When chemicals are added to the fire sprinkler system to prevent freezing, a high health hazard exists. This requires a higher, more expensive, level of protection, i.e., a Reduced Pressure Backflow Assembly (RPBA). If the fire service and domestic service are combined, the fire service may not be turned off because of safety reasons.