Isometric Drawings and Analysis Flashcards
7 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 7 Isometric Drawings and Analysis flashcards as text
An isometric drawing shows a pipe transitioning from a 4-inch main to a 3-inch branch using a reducing fitting. What type of fitting is most likely shown?
Answer: A reducing wye or tee
A reducing wye or tee fitting is used to transition from a larger main to a smaller branch while maintaining proper flow direction in DWV systems.
In an isometric drawing, a P-trap is shown with its outlet connecting to a horizontal drain pipe. What is the maximum distance the trap outlet can be from the vent under most US codes?
Answer: 6 feet
Under most US plumbing codes, the trap-to-vent distance (trap arm length) for a P-trap must not exceed the distances in the code table, typically 6 feet for a 1.5" trap.
When reviewing an isometric drawing of a water supply system, what symbol typically indicates a gate valve?
Answer: Two triangles touching at their points with a line through them
Gate valves are typically shown on isometric drawings as two triangles touching at their points (bow-tie shape) representing the wedge gate.
An isometric drawing shows a hot water return line looping back to the water heater. What is the primary purpose of this loop as read from the drawing?
Answer: To maintain hot water temperature throughout the supply system
A hot water return line circulates water back to the heater to maintain temperature throughout the distribution system, eliminating long waits for hot water.
On an isometric plumbing drawing, a double sanitary tee (back-to-back) is shown in a vertical stack. What is it primarily used for?
Answer: Serving two back-to-back fixtures such as two bathrooms on opposite sides of a wall
A double sanitary tee installed in a vertical stack serves back-to-back fixtures on opposite sides of a wall, such as two bathroom groups.
In an isometric drawing of a gas piping system, what does a union fitting allow the installer to do that a coupling does not?
Answer: Disconnect piping without cutting or threading
A union fitting has three parts that allow the piping to be disconnected and reconnected without cutting, which is essential for appliance servicing.
An isometric drawing shows a backflow preventer on a domestic water service. What is its function?
Answer: To prevent contaminated water from flowing back into the potable supply
A backflow preventer stops contaminated or non-potable water from reversing into the potable water supply due to back-pressure or back-siphonage.