The thickness of the drum metal is ______ inches given MAWP 2500 psi, diameter 5 ft, tensile strength 65,000 psi, joint efficiency 100%.

The thickness of the drum metal is ______ inches given MAWP 2500 psi, diameter 5 ft, tensile strength 65,000 psi, joint efficiency 100%.

• A. 1.00"
• B. 1.25"
• C. 1.50"
• D. 1.75"

Answer: (B)

The key idea is using the hoop-stress relationship for a cylindrical pressure vessel: t = P × D / (2 × S × E). Here P is the internal pressure (MAWP), D is the diameter, S is the allowable stress (material strength), and E is the joint efficiency. Since joint efficiency is 100%, E = 1. Convert the diameter to inches: D = 5 ft = 60 inches. With P = 2500 psi and S = 65,000 psi, the thickness comes out to t = (2500 × 60) / (2 × 65,000) = 150,000 / 130,000 ≈ 1.154 inches. Because you typically round up to meet safety and manufacturing standards, the next practical thickness is 1.25 inches. Therefore, the required drum metal thickness is about 1.25 inches.

The key idea is using the hoop-stress relationship for a cylindrical pressure vessel: t = P × D / (2 × S × E). Here P is the internal pressure (MAWP), D is the diameter, S is the allowable stress (material strength), and E is the joint efficiency. Since joint efficiency is 100%, E = 1.

Convert the diameter to inches: D = 5 ft = 60 inches. With P = 2500 psi and S = 65,000 psi, the thickness comes out to t = (2500 × 60) / (2 × 65,000) = 150,000 / 130,000 ≈ 1.154 inches.

Because you typically round up to meet safety and manufacturing standards, the next practical thickness is 1.25 inches. Therefore, the required drum metal thickness is about 1.25 inches.