1. What is a Water Pressure Pipe Flow Calculator?

Definition: This calculator estimates the volumetric flow rate of water through a pipe using the Hagen-Poiseuille equation.

Purpose: It helps engineers, plumbers, and designers determine water flow rates in pressurized pipe systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Volumetric flow rate (m³/s)
• \( r \) — Pipe radius (m)
• \( \Delta P \) — Pressure difference (Pa)
• \( \mu \) — Dynamic viscosity (Pa·s)
• \( L \) — Pipe length (m)

Explanation: The flow rate is directly proportional to the pressure difference and the fourth power of the radius, and inversely proportional to viscosity and pipe length.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculations ensure proper system design, adequate water supply, and efficient pipe sizing.

4. Using the Calculator

Tips: Enter pipe radius in meters, pressure difference in Pascals, viscosity (default 0.001002 Pa·s for water at 20°C), and pipe length in meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the viscosity of water?
A: At 20°C, water's dynamic viscosity is approximately 0.001002 Pa·s. This changes with temperature.

Q2: Does this work for any fluid?
A: Yes, but you must use the correct viscosity value for your specific fluid.

Q3: Why does radius have such a large effect?
A: Flow rate depends on r⁴, so doubling the radius increases flow by 16 times (2⁴ = 16).

Q4: What pressure units should I use?
A: The calculator uses Pascals (Pa). 1 psi ≈ 6894.76 Pa, 1 bar = 100,000 Pa.

Q5: Is this for laminar flow only?
A: Yes, this equation is accurate for laminar flow (Re < 2000). For turbulent flow, other equations like Darcy-Weisbach are more appropriate.