Cross-Connection Control Calculator

Assess hazards and select backflow prevention per UPC/IPC

Connection Details

Required Protection

Recommended Device --
Hazard Classification --
Minimum Air Gap --
Device Size --
Testing Required --
Code Reference --
Warning: Device recommendation placeholder

Backflow Device Types

Device Abbr Hazard Backpressure
Air GapAGSevereN/A
Reduced Pressure ZoneRPZHighYes
Double Check ValveDCLowYes
Press. Vacuum BreakerPVBHighNo
Atm. Vacuum BreakerAVBLowNo
Hose Bibb VBHBVBLowNo

Air Gap Requirements per UPC/IPC

Pipe Size Min Air Gap (1 wall) Min Air Gap (2 walls) Effective Opening
Up to 1/2"1"1-1/2"1/2"
3/4"1-1/2"2-1/4"3/4"
1"2"3"1"
1-1/4" to 1-1/2"2-1/2"3-3/4"1-1/2"
2"3"4-1/2"2"
2-1/2" to 3"4"6"3"
4"6"9"4"
Air gap = 2x effective opening (1 wall) or 3x (2 walls within 4D)

Common Cross-Connection Hazards

Low Hazard

  • Potable water loops
  • Fire sprinklers (no additives)
  • Food-grade equipment

High Hazard

  • Irrigation systems
  • Boiler makeup
  • Swimming pools
  • Garden hoses

Severe Hazard

  • Chemical tanks
  • Sewage pumps
  • Medical waste
  • Plating/coating

Testing

  • RPZ: Annual
  • DC: Annual
  • PVB: Annual
  • AG: Visual only