1. What is Hoop Stress in Pipelines?

Hoop stress (or circumferential stress) is the stress exerted circumferentially in both the pipe wall when pressure is applied. It's a critical parameter in pipeline design and integrity assessment.

2. How Does the Calculator Work?

The calculator uses the hoop stress equation:

Where:

• \( \sigma_h \) — Hoop stress (Pa)
• \( P \) — Internal pressure (Pa)
• \( D \) — Pipe diameter (m)
• \( t \) — Pipe wall thickness (m)

Explanation: The equation calculates the stress in the circumferential direction caused by internal pressure acting on the pipe wall.

3. Importance of Hoop Stress Calculation

Details: Hoop stress calculation is essential for pipeline design, safety assessment, and determining maximum allowable operating pressure. It helps prevent pipeline failures and ensures structural integrity.

4. Using the Calculator

Tips: Enter pressure in Pascals (Pa), diameter and thickness in meters (m). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for hoop stress in pipelines?
A: Hoop stress typically ranges from 20% to 72% of the specified minimum yield strength (SMYS) depending on design codes.

Q2: How does hoop stress relate to pipeline failure?
A: Excessive hoop stress can lead to yielding or rupture of the pipe wall, especially at defects or corrosion areas.

Q3: What safety factors are used with hoop stress?
A: Design codes typically specify safety factors of 0.72 or lower for hoop stress relative to SMYS.

Q4: Does this equation account for external pressure?
A: No, this is for internal pressure only. External pressure requires different buckling calculations.

Q5: How accurate is this formula for non-circular pipes?
A: This formula is specifically for circular pipes. Non-circular sections require more complex analysis.