1. What is Internal Pressure of Pipe?

Internal pressure of a pipe refers to the total pressure exerted by the fluid inside the pipe, which is the sum of gauge pressure and atmospheric pressure. This measurement is crucial for determining pipe strength requirements and safety margins.

2. How Does the Calculator Work?

The calculator uses the internal pressure equation:

Where:

• \( P_{int} \) — Internal pressure (Pa)
• \( P_g \) — Gauge pressure (Pa)
• \( P_{atm} \) — Atmospheric pressure (Pa)

Explanation: Gauge pressure measures pressure relative to atmospheric pressure, so adding atmospheric pressure gives the absolute internal pressure inside the pipe.

3. Importance of Internal Pressure Calculation

Details: Accurate internal pressure calculation is essential for pipe system design, material selection, safety valve setting, and compliance with pressure vessel codes and standards.

4. Using the Calculator

Tips: Enter gauge pressure and atmospheric pressure in Pascals (Pa). Both values must be non-negative. Standard atmospheric pressure is approximately 101,325 Pa.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between gauge pressure and absolute pressure?
A: Gauge pressure is pressure relative to atmospheric pressure, while absolute pressure includes atmospheric pressure. Internal pressure is absolute pressure.

Q2: Why is internal pressure important in pipe design?
A: Internal pressure determines the stress on pipe walls, which affects material selection, wall thickness, and safety factors in piping system design.

Q3: What units should I use for pressure calculations?
A: Pascals (Pa) are the SI unit for pressure. Other common units include psi, bar, or mmHg, but they should be converted to consistent units before calculation.

Q4: How does temperature affect internal pressure?
A: Temperature changes can affect both fluid pressure and material properties. For gases, pressure increases with temperature according to ideal gas law when volume is constant.

Q5: What safety factors should be considered?
A: Engineering codes typically require safety factors of 2-4 times the maximum expected internal pressure, depending on the application and fluid properties.