Isometric Analysis and Math 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 Analysis and Math flashcards as text
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.
A plumber needs to offset around a beam using 45-degree elbows. The diagonal (travel) distance is 18 inches. What is the set (offset) distance?
Answer: 12.73 inches
For a 45-degree offset, the set equals the travel multiplied by 0.707, so 18 × 0.707 ≈ 12.73 inches.
What is the constant used to calculate the travel of a 60-degree offset?
Answer: 1.155
The travel constant for a 60-degree offset is 1.155, meaning travel = set × 1.155.
In an isometric plumbing diagram, what does a line drawn vertically represent?
Answer: A pipe running plumb (vertical)
In isometric drawing conventions, vertical lines represent pipes that run plumb (true vertical).
A drain pipe drops 1/4 inch per foot over a run of 32 feet. What is the total drop?
Answer: 8 inches
Total drop = 32 feet × 0.25 inches/foot = 8 inches.
On an isometric drawing, which axis represents pipes running left-to-right (east-west) in the field?
Answer: The right-leaning 30-degree axis
By convention, the right-leaning 30-degree axis on an isometric drawing represents east-west (left-to-right) pipe runs.
A plumber must make a parallel offset of 6 inches using 45-degree fittings. What length of pipe is needed between the two elbows (the travel)?
Answer: 8.49 inches
Travel = set × 1.414, so 6 × 1.414 = 8.49 inches.