Mixed Deck — All Journeyman Plumbers Exam Topics Flashcards
100 cards from real Journeyman Plumbers Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 20 Mixed Deck — All Journeyman Plumbers Exam Topics flashcards as text
A listed gas range requires a flexible connector. What is the maximum length allowed for a residential gas appliance connector?
Answer: 6 feet
ANSI Z21.24 and NFPA 54 allow gas appliance connectors up to 6 feet in length for residential ranges, dryers, and similar appliances.
How far must a vent pipe terminal extend above a roof that is used for purposes other than weather protection?
Answer: 7 feet
When a roof is used as a deck, garden, or other occupied space, vent terminals must extend at least 7 feet above the roof surface to protect occupants from sewer gases.
What is the minimum slope for a horizontal wet vent pipe?
Answer: 1/4 inch per foot
Horizontal wet vent pipes must slope at least 1/4 inch per foot toward the drain to maintain proper flow and self-scouring velocity.
A pilot light that repeatedly goes out on a gas appliance most likely indicates a problem with:
Answer: The thermocouple or thermopile
The thermocouple generates a small voltage when heated by the pilot flame; if it fails or is positioned incorrectly, it causes the safety valve to close, extinguishing the pilot.
When reading an isometric drawing, a plumber sees two parallel pipes that must be offset around the same obstruction. What must be calculated for each pipe separately?
Answer: Both the travel and the spread between the offsets
For parallel offsets, each pipe needs its own travel calculated, and the spread (center-to-center distance) must account for fitting dimensions.
An RPZ assembly must be installed how far above the floor or ground to allow for drainage and testing?
Answer: At least 12 inches
RPZ assemblies require a minimum of 12 inches of clearance above the floor to allow access for testing and to permit relief port drainage.
Under the IPC, what is the maximum vertical distance a trap arm may run before connecting to the vent?
Answer: The developed length limit from the sizing table
The maximum trap-to-vent distance (trap arm length) is determined by the developed length limits in the IPC trap arm sizing table, which varies by pipe diameter.
What is the maximum hot water temperature allowed at a residential shower per the IPC?
Answer: 120°F
The IPC limits shower water temperature to 120°F (49°C) maximum to prevent scalding injuries.
A plumber finds that an existing 4-inch cast iron drain is cracked and must be replaced with PVC. The transition coupling used between cast iron and PVC must be:
Answer: A listed mechanical (Fernco-type) transition coupling
A listed mechanical transition (shielded) coupling is required to join dissimilar pipe materials like cast iron and PVC.
Which fixture is permitted to wet vent under most plumbing codes?
Answer: Bathroom group (lavatory, water closet, tub) on a single floor
A bathroom group on a single floor is the classic application of wet venting, where the lavatory drain serves as both a drain and a vent for the water closet.
What math constant is used to convert between the diagonal travel of a 45-degree offset and the set?
Answer: 0.707 (to get set from travel) or 1.414 (to get travel from set)
For 45-degree offsets: set = travel × 0.707, or travel = set × 1.414; both constants derive from the sine/cosine of 45 degrees.
Under IPC, an interceptor or separator is required for which of the following types of facilities?
Answer: Commercial kitchens and food service establishments
The IPC requires grease interceptors for commercial kitchens and food service facilities where grease-laden waste is discharged.
Which fitting is required when a drain changes direction from vertical to horizontal?
Answer: Long-sweep 1/4 bend or combination wye and 1/8 bend
A long-sweep 1/4 bend or a combination wye and 1/8 bend is required when transitioning from vertical to horizontal to ensure smooth, non-turbulent flow.
What is the minimum burial depth for metallic gas service piping installed underground outside a building?
Answer: 18 inches
Metallic gas piping buried outside must have a minimum cover of 18 inches to protect it from damage.
On an isometric drawing, a pipe running parallel to the right front edge of the cube is drawn at what angle from horizontal?
Answer: 30 degrees
In isometric drawing, the three primary axes are drawn at 30 degrees above horizontal (left and right) and vertical.
If an isometric drawing shows a trap with a vent line rising vertically from the trap arm, what type of venting does this most likely represent?
Answer: An individual or unit vent
A vent line rising vertically from the trap arm on an isometric drawing represents an individual or unit vent connecting to the vent stack.
It is necessary to pipe clear water waste from a potable source through an air gap, such as a relief valve on a water heater, to an indirect waste.
Answer: TRUE
It is required to pipe clear water waste from a potable water system to an indirect waste and discharge it through an air gap. This is as easy as terminating the discharge pipe of a floor drain six inches above the strainer.
A residential bathroom group consists of a standard toilet (3 DFU), a lavatory (1 DFU), and a bathtub with a shower (2 DFU). What is the total Drainage Fixture Unit (DFU) load that must be used to size the horizontal branch drain serving these fixtures?
Answer: The sum of the individual fixture DFU values
To size a horizontal branch drain, you must sum the Drainage Fixture Unit (DFU) values of all fixtures connecting to it. In this scenario, the total load is the sum of the toilet (3), lavatory (1), and bathtub/shower (2), which equals 6 DFU. This total value is then used with code tables to determine the minimum required pipe size.
When two or more water closets are on the same horizontal branch, which venting method is most efficient?
Answer: Using a circuit vent with a relief vent
A circuit vent with a relief vent efficiently serves a battery of water closets on the same horizontal branch, reducing pipe runs.
A 22.5-degree offset has a travel constant of approximately 2.613. If the set is 5 inches, what is the travel?
Answer: 13.07 inches
Travel = set × travel constant = 5 × 2.613 = 13.07 inches.