Technical Committee on Backflow Preventors and Water
Pressure Reducing Valves
Preface
Foreword
1 Scope
2 Reference Publications, Definitions, Abbreviations
    and Symbols
    2.1 Reference Publications
    2.2 Definitions
    2.3 Abbreviations
    2.4 Symbols
3 Backflow Prevention Methods and Devices
    3.1 Air Gap
    3.2 Barometric Loop
    3.3 Mechanical Protection Devices
          3.3.1 Available Types
          3.3.2 Vacuum Breaker Backflow Preventers -
                  General
          3.3.3 Vacuum Breaker, Atmospheric Type (AVB)
          3.3.4 Vacuum Breaker, Pressure Type (PVB)
          3.3.5 Vacuum Breaker, Hose Connection Type (HCVB)
          3.3.6 Backflow Preventer, Dual Check Valve Type
                  with Atmospheric Port (DCAP)
          3.3.7 Backflow Preventer, Reduced Pressure
                  Principle Type (RP)
          3.3.8 Backflow Preventer, Double Check Valve
                  Type (DCVA)
          3.3.9 Backflow Preventer, Dual Check Valve
                  Type (DuC)
          3.3.10 Vacuum Breaker, Laboratory Faucet Type (LFVB)
          3.3.11 Backflow Preventer, Dual Check Valve Type
                  with Intermediate Vent (DuCV)
4 Selection of Backflow Prevention Devices
    4.1 Selection of Backflow Prevention Devices
    4.2 Categories of Hazards
    4.3 Principal Ways of Providing Protection
          4.3.1 General
          4.3.2 Individual Protection
          4.3.3 Zone or Area Protection
          4.3.4 Premises Isolation
    4.4 Selection Guide
5 Installation of Backflow Prevention Devices
    5.1 General Requirements
    5.2 Sizing
    5.3 Temperature and Pressure Limitations
    5.4 Shutoff (Isolating) Valves and Test Cocks
    5.5 Strainers
    5.6 Location
    5.7 Parallel Service
    5.8 Spillage
    5.9 Thermal Expansion
    5.10 Installation Orientation
    5.11 Protection from Freezing
6 Maintenance and Field Testing
    6.1 General
          6.1.1 Devices to be Field Tested
          6.1.2 Frequency of Field Testing
          6.1.3 Certified Backflow Prevention Device Tester
          6.1.4 School Accreditation
          6.1.5 Tester Licensing/Registration
    6.2 Maintenance
          6.2.1 General
          6.2.2 RP Assemblies
    6.3 Field Testing - General
    6.4 Field Testing of Pressure Type Vacuum Breakers
          6.4.1 Field Testing of Pressure Type Vacuum
                  Breakers Using the Visual Test Method
          6.4.2 Field Testing of Pressure Type Vacuum
                  Breakers for Sizes NPS-3/4 to 2 using
                  the Sight Tube Method
    6.5 Field Testing of Reduced Pressure Principle
          Backflow Preventers Using a Differential
          Pressure Gauge
          6.5.1 Equipment Required
          6.5.2 Test No. 1 (RP)
          6.5.3 Test No. 2 (RP)
          6.5.4 Test No. 3 (RP)
          6.5.5 Test no. 4 (RP)
          6.5.6 Test No. 5 (RP)
          6.5.7 Test No. 6 (RP)
          6.5.8 Putting the Valve Back into Service
    6.6 Field Testing of Double Check Valve Assembly
          Backflow Preventers Using a Duplex Gauge
          6.6.1 Equipment Required
          6.6.2 Test No. 1 (DCVA)
          6.6.3 Test No. 2 (DCVA)
          6.6.4 Putting the Valve Back into Service
    6.7 Field Testing of Double Check Valve Assembly
          Backflow Preventers Using the Sight Tube Method
          6.7.1 Equipment Required
          6.7.2 Test No. 1A (DCVA)
          6.7.3 Test No. 1B (DCVA)
          6.7.4 Test No. 2A (DCVA)
          6.7.5 Test no. 2B (DCVA)
          6.7.6 Test no. 3 (DCVA)
          6.7.7 Test no. 4A (DCVA)
          6.7.8 Test no. 4B (DCVA)
          6.7.9 Putting the Valve Back into Service
Appendices
A How Backflow May Occur
B Guide to the Assessment of Hazard and Selection of
    Backflow Preventers for Individual, Area or Premises
    Isolation
C Water-Hauling Equipment and Backflow Devices
D Conversion Tables