1. What is Shell Thickness Calculation?

The shell thickness calculation determines the required thickness of a pressure vessel's shell to safely contain internal pressure. It's a fundamental calculation in pressure vessel design and mechanical engineering.

2. How Does the Calculator Work?

The calculator uses the shell thickness formula:

Where:

• \( P \) — Internal pressure (Pascals)
• \( r \) — Inner radius of the shell (meters)
• \( \sigma \) — Allowable stress of the material (Pascals)
• \( E \) — Joint efficiency factor (0-1)

Explanation: The equation balances the hoop stress caused by internal pressure with the material's strength, accounting for weld joint efficiency.

3. Importance of Shell Thickness Calculation

Details: Proper shell thickness calculation is critical for pressure vessel safety, preventing catastrophic failure while optimizing material usage and cost.

4. Using the Calculator

Tips: Enter pressure in Pascals, radius in meters, allowable stress in Pascals, and joint efficiency as a decimal (0-1). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What units should I use for input?
A: The calculator uses SI units: Pascals for pressure/stress, meters for radius. Results are in millimeters.

Q2: How is joint efficiency determined?
A: Joint efficiency depends on weld type and inspection method, typically ranging from 0.6 to 1.0. Consult ASME codes for exact values.

Q3: Does this account for corrosion allowance?
A: No, this calculates minimum theoretical thickness. Add corrosion allowance based on service conditions.

Q4: What safety factors are included?
A: The allowable stress (σ) should already incorporate appropriate safety factors per applicable design codes.

Q5: Is this formula valid for all pressure vessels?
A: This is for thin-walled cylindrical shells (r/t > 10). Thick-walled vessels require more complex calculations.