1. What is Dished Head Thickness?

Definition: Dished Head Thickness is the required thickness of a pressure vessel's dished end to safely contain internal pressure.

Purpose: It ensures the vessel head can withstand operational pressures while accounting for material properties and safety factors.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( th_{dished} \) — Dished head thickness (mm)
• \( p \) — Internal pressure in vessel (N/mm²)
• \( R_c \) — Crown radius (mm)
• \( W \) — Stress intensification factor
• \( f_j \) — Allowable stress for jacket material (N/mm²)
• \( J \) — Joint efficiency for shell
• \( c \) — Corrosion allowance (mm)

Explanation: The formula calculates the minimum required thickness considering pressure, material strength, and adds corrosion allowance.

3. Importance of Dished Head Thickness Calculation

Details: Proper thickness calculation ensures vessel safety, prevents failures, and complies with pressure vessel design codes.

4. Using the Calculator

Tips: Enter all required parameters. Default values are provided where applicable. All values must be > 0 except corrosion allowance.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical stress intensification factor?
A: Typically ranges from 1.0 to 2.5 depending on head geometry and loading conditions.

Q2: How is joint efficiency determined?
A: It depends on the joint type and extent of radiography, typically 0.7-1.0 for welded joints.

Q3: When is corrosion allowance needed?
A: For materials susceptible to corrosion, typically 1-3mm for carbon steel in corrosive service.

Q4: What standards govern dished head design?
A: ASME BPVC Section VIII, EN 13445, and other pressure vessel codes provide design rules.

Q5: How accurate is this calculation?
A: This provides an initial estimate. Final design should be verified against applicable codes.

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