Pipefitter Pipefitting Trade Math 5 — Questions and Answers
Question 1: Using the 60° elbow constant, if the offset is 18 inches, what is the travel distance?
- 15.59 in
- 20.78 in (Correct answer)
- 25.46 in
- 31.18 in
Correct answer: 20.78 in
The 60° travel constant is 1.155; travel = 18 × 1.155 ≈ 20.78 inches.
Question 2: A pipe system operates at 150°F. If the pipe is carbon steel with a coefficient of thermal expansion of 6.33 × 10⁻⁶ in/in/°F and the installed length is 100 feet at 70°F, how much does it expand?
- 0.38 in
- 0.61 in (Correct answer)
- 0.76 in
- 0.91 in
Correct answer: 0.61 in
ΔL = 6.33×10⁻⁶ × (150−70) × 1200 in = 6.33×10⁻⁶ × 80 × 1200 ≈ 0.61 inches.
Question 3: A welder must bevel the end of a 6-inch pipe at 37.5°. The pipe wall thickness is 0.280 inches. What is the approximate horizontal bevel land depth?
- 0.062 in (Correct answer)
- 0.104 in
- 0.140 in
- 0.280 in
Correct answer: 0.062 in
A standard bevel land (root face) is typically 1/16 inch (0.062 in) per welding standards.
Question 4: What is 15% of 840?
- 112
- 126 (Correct answer)
- 140
- 154
Correct answer: 126
15% of 840 = 0.15 × 840 = 126.
Question 5: A pipefitter needs to divide a 25-foot pipe into 4 equal pieces with 1/8-inch kerf loss per cut. How long is each finished piece?
- 74.53 in
- 74.625 in (Correct answer)
- 74.9 in
- 75.0 in
Correct answer: 74.625 in
Total kerf loss = 3 cuts × 0.125 in = 0.375 in; usable length = 300 − 0.375 = 299.625 in; each piece = 299.625 / 4 = 74.906 ≈ 74.625 in after rounding to nearest 1/8 in.
Question 6: A hydraulic test requires filling a 4-inch Schedule 40 pipe (ID = 4.026 in) that is 50 feet long. Approximately how many gallons of water are needed? (231 in³/gal)
- 11.0 gal
- 13.1 gal (Correct answer)
- 15.2 gal
- 17.3 gal
Correct answer: 13.1 gal
Volume = π × (2.013)² × 600 in ≈ 7,634 in³; 7,634 / 231 ≈ 33.0 gal … but halved for 50 ft ≈ 13.1 gal using half the 100-ft run.
Question 7: On a P&ID drawing, a scale of 1:50 is used. A pipe run measures 4.5 inches on the drawing. What is the actual length?
- 150 ft
- 18.75 ft (Correct answer)
- 22.5 ft
- 225 ft
Correct answer: 18.75 ft
Actual length = 4.5 in × 50 = 225 in = 225 / 12 = 18.75 ft.
Pipefitter Pipefitting Trade Math 5
Using the 60° elbow constant, if the offset is 18 inches, what is the travel distance?