Backflow Preventer Selection
Select appropriate backflow assembly based on hazard and application
Application Details
High hazard: substance could cause illness or death
Backpressure: downstream pressure can exceed supply
Sizing Information
Recommended Backflow Device
Primary Selection
--
Device Size
--
ASSE Standard
--
Pressure Loss
--
Velocity
--
Alternative Device
--
Note: Device must be tested annually by certified tester.
Device Types
AG (Air Gap) - ASSE 1001
Physical separation, highest protection
RPBA - ASSE 1013
Reduced Pressure Backflow Assembly
DCVA - ASSE 1015
Double Check Valve Assembly
PVB - ASSE 1020
Pressure Vacuum Breaker
SVB - ASSE 1056
Spill-Resistant Vacuum Breaker
Backflow Device Selection Matrix
| Application | Hazard | Backpressure | Required Device |
|---|---|---|---|
| Fire Sprinkler (no additives) | Low | Yes | DCVA |
| Fire Sprinkler (w/antifreeze) | High | Yes | RPBA |
| Irrigation (potable supply) | High | No | PVB or SVB |
| Irrigation (w/chemicals) | High | Yes | RPBA |
| Boiler Fill | High | Yes | RPBA |
| Swimming Pool | High | Varies | AG or RPBA |
| Medical/Lab | High | Yes | AG or RPBA |
| Commercial Kitchen | High | No | AVB or RPBA |
| Residential Service | Low | No | DCVA |
Typical Pressure Loss (PSI)
| Size | RPBA @ rated flow | DCVA @ rated flow | PVB @ rated flow |
|---|---|---|---|
| 3/4" | 12-15 | 5-8 | 8-12 |
| 1" | 10-14 | 4-7 | 7-10 |
| 1-1/2" | 8-12 | 3-6 | 6-9 |
| 2" | 7-11 | 3-5 | 5-8 |
| 3" | 5-9 | 2-4 | -- |
| 4" | 4-8 | 2-4 | -- |
| 6" | 3-6 | 1-3 | -- |