ASSE 5150 study guide
ASSE 5150 · Work through your exam, one topic at a time.
ASSE 5150 is a recertification credential for people who test backflow prevention assemblies - the devices that stop contaminated water from reversing into a potable supply. Candidates are typically plumbing inspectors, water utility staff, plumbing contractors, and cross-connection control personnel who already hold an initial tester certification and must show that their knowledge and field practice are current. The ASSE 5150 study guide has 8 sections and about 2,087 words.
01Plumbing and Mechanical Code Fundamentals
Code exams reward candidates who read definitions before they read requirements. Start with scope: what the plumbing code governs (water supply, fixtures, drainage, venting, special wastes) versus what the mechanical code governs (HVAC, refrigeration, combustion air, fuel gas piping where adopted separately).
303 words, about 2 min02Water Supply and Distribution Systems
Water supply questions test three linked ideas: adequate pressure at the most remote fixture, correct pipe sizing for demand, and protection against contamination. Learn the flow-pressure relationship: residual pressure falls as flow rises, so a static pressure reading alone does not prove adequacy.
267 words, about 1 min03Sanitary Drainage, Venting, and Storm Drainage
Drainage design depends on slope, pipe size, and fixture-unit load. Know the standard slopes (1/4 inch per foot for smaller horizontal branches, 1/8 inch per foot for larger pipes where permitted) and why too little slope causes solids to settle while too much slope lets liquids outrun solids.
274 words, about 1 min04Fixtures, Fixture Fittings, and Water Heaters
Fixture questions test spacing, clearance, accessibility, and the water and drainage connections each fixture needs. Know the required clearances in front of and beside fixtures, the difference between a water closet compartment and a bathroom, and which fixtures must be accessible in public facilities.
271 words, about 1 min05Cross-Connection Control and Backflow Prevention
Backflow occurs by backsiphonage (negative pressure in the supply) or backpressure (downstream pressure exceeding supply pressure). Learn to identify which mechanism applies to a scenario, because device selection follows from the mechanism and hazard level.
243 words, about 1 min06Inspection, Testing, and Plan Review
Inspection questions test the sequence and content of inspections: underground rough-in, rough-in, final, and special inspections. Know what must be visible before concealment and what tests are required for water supply, drainage, and gas piping.
237 words, about 1 min07Administration, Permits, and Code Enforcement
Administration questions test when a permit is required, who may perform work, and how the AHJ enforces the code. Know that a permit is generally required for new installation, alteration, and replacement of plumbing systems, with limited exceptions for minor repairs.
267 words, about 1 min08Safety, Materials, and Special Plumbing Systems
Material questions test which pipe and fittings are permitted for each service and how they must be joined. Know that potable water materials must be listed for potable use, that dissimilar metals need dielectric protection, and that solvent cement and primer must match the pipe material.
225 words, about 1 min