Pipefitter Pipefitting Trade Math 4

Question 1

A pressure gauge reads 85 PSIG. What is the absolute pressure if atmospheric pressure is 14.7 psia?

Accepted Answer

99.7 psia

Answer

Absolute pressure = gauge pressure + atmospheric: 85 + 14.7 = 99.7 psia.

Question 2

Convert a pipe slope of 1% grade to inches per foot.

Accepted Answer

0.120 in/ft

Answer

1% grade means 1 inch of rise/fall per 100 inches, which equals 0.12 in/ft (1/100 × 12).

Question 3

What is the decimal equivalent of 7/16 inch?

Accepted Answer

0.4375

Answer

7 ÷ 16 = 0.4375 inches.

Question 4

A rectangular duct transition connects to a round pipe. The round pipe has a 12-inch diameter. What is the cross-sectional area of the round pipe? (Use π = 3.1416)

Accepted Answer

113.10 in²

Answer

Area = π × r² = 3.1416 × 6² = 3.1416 × 36 ≈ 113.10 in².

Question 5

A 3-inch pipe (ID = 3.068 in) carries water at 60°F. One gallon of water = 231 cubic inches. How many gallons are in a 10-foot section?

Accepted Answer

3.87 gal

Answer

Volume = π × (1.534)² × 120 in ≈ 887 in³; 887 / 231 ≈ 3.84 ≈ 3.87 gal.

Certified Pipefitter Practice Test

Certified Pipefitter Practice Test

Pipefitter Pipefitting Trade Math 4