Master Plumber Exam Cheat Sheet 2026

The 30 highest-yield Master Plumber Exam facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What does 'PN6' designation mean for PVC pressure pipes used in water supply systems in the Philippines? → Pressure Nominal rating of 6 bar (600 kPa)
2. Which of the following factors determines the license requirements: → Authority having jurisdiction
3. In the Philippine Plumbing Code, what is the term for the pipe connecting a fixture trap to the vent system? → Trap arm
4. Which of the following statements is a mandatory and correct installation requirement for an Atmospheric Vacuum Breaker (AVB)? → It must be installed at least 6 inches above all downstream piping and outlets.
5. Under the IPC, what is the maximum number of bathroom groups on the same floor level that can be served by a single horizontal wet vent? → Two
6. Which of the following fittings is generally prohibited for use in a sanitary drainage system when changing from a horizontal to a vertical direction? → Sanitary tee
7. Under the NPCP, what is the minimum slope (grade) required for a 100 mm (4-inch) horizontal drainage pipe? → 1:100 (1%)
8. What is the purpose of a dip tube inside a storage-type water heater? → To direct cold incoming water to the bottom of the tank
9. What is the first-hour rating (FHR) of a storage water heater? → The gallons of hot water the heater can supply in one hour starting with a full tank
10. To prevent backflow, sill cocks, hose bibs, and water heaters are typically equipped with ___. → A vacuum breaker
11. How long can gray water be kept in storage before it can be used to flush a toilet or urinal? → 72 hours
12. Which of the following requires a plumbing permit to be replaced? → Water heater
13. In a multi-story building, a drainage stack has a horizontal offset. Under which condition is special venting for the offset required according to the IPC? → When five or more branch intervals are located above the horizontal offset.
14. What is the PRC (Professional Regulation Commission) license required before a person can legally supervise plumbing installation works in the Philippines? → Registered Master Plumber (RMP)
15. What is the recommended storage temperature for domestic hot water to prevent Legionella bacteria growth, per ASHRAE Guideline 12? → 140°F (60°C)
16. What happens if the size of a 4 inch pipe is decreased in the flow's direction? → This could cause blockage to build up at the reduction point.
17. In the hierarchy of backflow prevention methods, which of the following is considered the most positive and absolute form of protection? → An Air Gap
18. How many P-traps can a single trap arm support in total? → 1
19. A laundry chute has gas piping installed. → Is a code violation
20. Who holds the ultimate legal responsibility for ensuring that a required plumbing permit is obtained before work commences on a privately owned property? → The property owner.
21. What size of an unobstructed exit opening is required for a standard shower when a shower door is installed? → 22 inches
22. It is necessary for flexible water connections to be _____. → Accessible
23. According to most model plumbing codes, what is the maximum allowable horizontal distance for a cleanout on a 4-inch building drain? → 100 feet
24. Which of the following methods can be used to check for leaks in a DWV system? → All of the above
25. Which of the following connections to a sanitary drainage system is seen to be the most effective? → Air gap
26. Under federal law, what is the primary purpose of a mechanic's lien filed by a plumbing contractor? → To secure a legal claim against the property itself as collateral for the unpaid debt.
27. Vacuum pump exhaust must be discharged into the following areas in Med Gas systems: → Outdoors
28. According to the Americans with Disabilities Act (ADA) standards, what is the maximum height from the finished floor to the rim of a compliant lavatory or sink? → 34 inches
29. How tall would a handicap toilet likely be? → 18 inches
30. A tankless water heater must deliver 2.5 GPM with a 70°F temperature rise. Approximately how many BTU/hr must it produce? → 87,500 BTU/hr