1. What is a Pipe Diameter Calculator?

Definition: This calculator determines the required pipe diameter based on flow rate and flow velocity using the continuity equation.

Purpose: It helps engineers, plumbers, and designers select the appropriate pipe size for fluid transport systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( D \) — Pipe diameter (meters)
• \( Q \) — Volumetric flow rate (m³/s)
• \( v \) — Flow velocity (m/s)
• \( \pi \) — Pi constant (~3.1416)

Explanation: The formula derives from the continuity equation (Q = v × A), solving for diameter from the circular cross-sectional area.

3. Importance of Pipe Diameter Calculation

Details: Proper pipe sizing ensures efficient flow, prevents excessive pressure drops, and avoids costly oversizing or problematic undersizing.

4. Using the Calculator

Tips: Enter the flow rate in m³/s and desired flow velocity in m/s (default 1.0 m/s for water). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical flow velocity for water pipes?
A: For water, 0.9-2.4 m/s is common in supply lines, with 1.0-1.5 m/s often recommended for balance between efficiency and noise.

Q2: How does pipe material affect the calculation?
A: Material affects friction loss but not diameter calculation. However, select standard available sizes after calculation.

Q3: Can I use this for gases?
A: Yes, but gas velocities are typically higher (15-30 m/s for compressed air, 5-10 m/s for natural gas).

Q4: What if I get a very small diameter?
A: Ensure your units are correct (m³/s for flow). For very small flows, consider minimum practical pipe sizes.

Q5: Does this account for friction losses?
A: No, this is for diameter only. Use additional calculations (e.g., Darcy-Weisbach) to verify pressure drops.