Home Back

Thickness of Bottom Head subjected to Pressure Calculator

Head Thickness Formula:

\[ th = 4.4 \times Rc \times (3 \times (1 - u^2))^{1/4} \times \sqrt{\frac{p}{2 \times E}} \]

mm
N/mm²
N/mm²
mm

1. What is Thickness of Bottom Head Calculator?

Definition: This calculator determines the required thickness of a pressure vessel's bottom head based on material properties and operating conditions.

Purpose: It helps engineers ensure structural integrity of pressure vessels under internal pressure.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ th = 4.4 \times Rc \times (3 \times (1 - u^2))^{1/4} \times \sqrt{\frac{p}{2 \times E}} \]

Where:

  • \( th \) — Head thickness (mm)
  • \( Rc \) — Crown radius (mm)
  • \( u \) — Poisson ratio (±5%)
  • \( p \) — Internal pressure (N/mm²)
  • \( E \) — Modulus of elasticity (N/mm²)

Explanation: The formula calculates the minimum required thickness to withstand the internal pressure while considering material properties.

3. Importance of Head Thickness Calculation

Details: Proper thickness calculation ensures pressure vessel safety, prevents failures, and meets regulatory requirements.

4. Using the Calculator

Tips: Enter crown radius, Poisson ratio (default 0.3), internal pressure, and modulus of elasticity (default 170000 N/mm² for steel). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical Poisson ratio value?
A: For most metals, it's about 0.3 (±5%), but varies by material.

Q2: How do I determine crown radius?
A: It's typically the diameter of the vessel head divided by 2.

Q3: What safety factors should I consider?
A: The calculated thickness is theoretical minimum. Always add corrosion allowance and consider safety factors.

Q4: What units should I use?
A: Consistent units are required (mm for dimensions, N/mm² for pressure/stress).

Q5: Does this apply to all head types?
A: This formula is specifically for certain head shapes (like torispherical heads). Different formulas exist for other geometries.

Thickness of Bottom Head Calculator© - All Rights Reserved 2025