ASSE 5110 common mistakes
ASSE 5110 · Understand the traps and how to avoid them.
On scenario items, labels a submerged inlet fed by a positive downstream pump as backsiphonage, or labels a negative supply-pressure condition as backpressure.
Memorizes the definitions as slogans instead of comparing supply and downstream pressure directions.
What to do instead
Draw the pressure gradient before answering: backsiphonage requires supply pressure below atmospheric; backpressure requires downstream pressure higher than supply pressure.
Fails to identify an indirect cross-connection, such as a garden hose submerged in a bucket or a chemical injector connected through a hose bibb, because no permanent pipe-to-pipe connection is visible.
Equates cross-connection only with direct piping and overlooks temporary or indirect connections.
What to do instead
Inspect every point of use for a potential path, including hoses, fill lines, injectors, and submerged inlets, and classify each as direct or indirect.
Cites one national standard as universally controlling and ignores the local ordinance, utility rule, or state primacy requirement that actually governs the installation.
Study material summarizes national standards but local codes may be stricter or may adopt different editions.
What to do instead
Learn the hierarchy: federal minimums, state adoption, local ordinance, and utility requirements; on exam items, apply the stricter or specifically cited authority.
States that every backflow device must be field-tested annually with a differential test kit, including atmospheric vacuum breakers and air gaps.
Overgeneralizes from testable assemblies to all backflow protection methods.
What to do instead
Separate testable assemblies from non-testable devices; know which require annual field testing and which require inspection, maintenance, or air-gap verification instead.
Selects an atmospheric vacuum breaker for an irrigation zone with electric solenoid valves downstream.
Chooses the smallest or least expensive device without checking continuous-pressure and downstream-shutoff limitations.
What to do instead
Use an AVB only where there is no downstream shutoff and no continuous pressure; for zones with valves or continuous pressure, select a PVB, SVB, or RPZ as the code permits.
Approves an RPZ installation without confirming that the relief-valve discharge terminates through a proper air gap to a drain or safe location.
Focuses on the assembly's backflow function and neglects installation and drainage requirements.
What to do instead
Verify the relief discharge is piped to a drain through an air gap, is not subject to flooding or freezing, and remains accessible for testing and maintenance.
Connects test-kit hoses to the wrong test cocks or opens and closes test cocks in the wrong sequence during an RPZ, double check, or PVB test.
Memorizes numbered steps without tracing the actual flow path through the assembly and test kit.
What to do instead
Practice on a training bench and trace each hose connection; follow the manufacturer and recognized test procedure sequence exactly before reading pressures.
Takes pressure readings without purging air from the hoses, without zeroing the gauges, or without checking the test-kit calibration date.
Rushes the setup and trusts the kit without verifying its condition.
What to do instead
Check the calibration sticker and gauge condition, zero the gauges, bleed all hoses, and allow readings to stabilize before recording results.
Replaces the RPZ relief valve when the actual cause of continuous discharge is a fouled or leaking check valve.
The visible symptom points to the relief valve, so the technician repairs the symptom rather than diagnosing the root cause.
What to do instead
Isolate and test the check valves first; confirm which check valve is leaking or fouled, then clean or replace the correct component and retest the assembly.
Submits a test report missing the assembly make, model, size, serial number, test-kit calibration information, gauge serial number, repair details, or tester signature.
Treats the report as a formality rather than a regulated record that must support enforcement and retesting.
What to do instead
Use a required-fields checklist and verify every entry before submission, including initial, repair, and annual test status and all equipment identification.