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Cheat sheet

Backflow Tester Cheat Sheet

Practice QuestionsStudy Guide

Hydraulic Principles

30%of exam

Backflow TypesPressureHazardCross-ConnectionSelection Picker

Assemblies Equipment

30%of exam

RP AssemblyDC AssemblyPVB SVBCheck ValvesTroubleshooting

Field Test Procedures

20%of exam

Test SetupRP TestDC TestPVB TestTest Picker

Cross-Connection Control

10%of exam

ContainmentIsolationSurveysAir GapHazard Rating

Field Test Equipment

5%of exam

Differential GaugeHosesTest CocksBleedingCalibration

Codes Regulations

5%of exam

SDWAPurveyorRecordsReportingRecertification

Quick Facts

Exam
Backflow Tester
Bodies
ABPA / ASSE
Written
100 questions
Time
3 hours
Pass
70%
Practical
Hands-on testing
Assemblies
RP DC PVB SVB
Validity
3 years
Gauge
Annual calibration

Two Backflows

Pressure pushes; siphon pulls.

BackpressureBacksiphonage

Backpressure vs Backsiphonage

Backpressure

  • Downstream pressure higher
  • Pumps/boilers cause

Backsiphonage

  • Supply pressure drops
  • Vacuum draws back

Pressure direction decides

Selection Picker

  1. Health hazard→RP or air gap
  2. Low hazard→DC
  3. Backpressure exists→RP/DC(Not PVB)
  4. Backsiphonage only→PVB/SVB
  5. Maximum protection→Air gap
  6. Fixture protection→Isolation

Hydraulics Basics

Backflow
Reverse flow
Backpressure
Downstream pressure higher
Backsiphonage
Supply pressure drops
Static pressure
No-flow pressure
Dynamic pressure
Flowing pressure
Pressure loss
Drop across device

RP Parts

Check, zone, relief, check.

Check 1ZoneReliefCheck 2

RP vs DC

RP

  • Relief valve present
  • High hazard use

DC

  • No relief valve
  • Low hazard use

Health hazard needs RP

Failure Picker

  1. Reading unstable→Bleed hoses
  2. Check leaks→Clean seat
  3. Relief won't open→Inspect diaphragm
  4. Shutoff leaks→Repair shutoff
  5. Gauge suspect→Check calibration
  6. Wrong assembly→Hazard review

RP Assembly

RP
Reduced pressure principle
Check 1
Creates zone pressure
Check 2
Prevents outlet return
Relief valve
Vents failed zone
Zone
Reduced pressure area
Use
High hazard protection

PVB vs SVB

PVB

  • Vacuum breaker
  • May spill water

SVB

  • Spill-resistant design
  • Vacuum breaker

Both backsiphonage only

DC Assembly

DC
Double check assembly
Check 1
First closure point
Check 2
Second closure point
Shutoff 1
Inlet isolation
Shutoff 2
Outlet isolation
Use
Low hazard protection

Device vs Assembly

Device

  • Often non-testable
  • No test cocks

Assembly

  • Field testable
  • Has shutoffs/cocks

Testability matters

PVB SVB

PVB
Pressure vacuum breaker
SVB
Spill-resistant breaker
Air inlet
Opens on vacuum
Check valve
Holds downstream water
Backpressure
Not protected
Elevation
Install above outlets

Troubleshooting

Debris
Fouls check seat
Scale
Restricts movement
Spring
Weak closure force
Diaphragm
Relief valve failure
Leaky shutoff
Invalid test
Air in hose
Unstable reading

Test Start

Identify, isolate, connect, bleed.

IdentifyIsolateConnectBleed

Test Picker

  1. Before connection→Gauge zero
  2. Hoses attached→Bleed air
  3. RP assembly→Relief plus checks
  4. DC assembly→Two checks
  5. PVB/SVB→Air inlet/check
  6. Any failure→Repair retest

Test Setup

Permission
Notify responsible party
Flow direction
Confirm before testing
Test cocks
Open slowly
Bleed hoses
Remove trapped air
Gauge zero
Check before readings
Record
Document findings

RP Test Logic

Relief opening
Must open
Zone pressure
Lower than supply
Check 1
Holds differential
Check 2
Holds backpressure
Shutoff 2
Must be tight
Fail
Repair then retest

DC PVB Tests

DC check 1
Must hold tight
DC check 2
Must hold tight
DC shutoff
No leakage
PVB check
Holds pressure
Air inlet
Opens to atmosphere
SVB spill
Minimized discharge

Containment vs Isolation

Containment

  • Service entrance
  • Protects public system

Isolation

  • Individual fixture
  • Protects internal users

Location decides

Hazard Control

Cross-connection
Potable/nonpotable link
Pollution
Aesthetic quality hazard
Contamination
Health hazard
Containment
Service protection
Isolation
Fixture protection
Air gap
Physical separation

Pollution vs Contamination

Pollution

  • Aesthetic concern
  • Non-health hazard

Contamination

  • Health concern
  • Toxic/pathogenic hazard

Health risk escalates

Test Kit

Differential gauge
Measures pressure difference
High hose
Connect upstream side
Low hose
Connect downstream side
Bypass hose
Equalizes as needed
Calibration
Check yearly
Needle valves
Control gauge flow

Report Basics

Assembly, readings, result, signature.

AssemblyReadingsResultSignature

Records Regs

SDWA
Drinking water law
Purveyor
Water supplier
Authority
Local program rules
Report
Submit test results
Serial number
Assembly identifier
Recertify
Renew credential

Common Traps

PVB Trap

Backsiphonage only ≠ Backpressure protection

Hazard Trap

Pollution ≠ Contamination

Gauge Trap

Air in hose ≠ True pressure

Shutoff Trap

Leaky shutoff ≠ Valid test

RP Trap

Relief valve opens ≠ Relief valve closed

Location Trap

Containment ≠ Isolation

Last Minute

  1. 1.Name two backflow types
  2. 2.Classify hazard first
  3. 3.Match assembly to hazard
  4. 4.Confirm flow direction
  5. 5.Bleed gauge hoses
  6. 6.Test shutoffs matter
  7. 7.RP relief must open
  8. 8.PVB excludes backpressure
  9. 9.Record serial number
  10. 10.Repair then retest

Backflow Prevention Assembly Tester

Practice QuestionsStudy GuideCheat SheetFlashcards1 blog

Conquer the Backflow Prevention Device Exam: Comprehensive Study Guide for Vacuum Breakers, Valve Assemblies, Pressure Differentials, Relief ... and Troubleshooting (Skilled Trades Exams)

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