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Calculate Pipe Pressure from Flow Rate

Pipe Pressure Formula:

\[ \Delta P = \frac{8 \times \mu \times L \times Q}{\pi \times r^4} \]

Pa·s
m
m³/s
m

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1. What is Pipe Pressure from Flow Rate?

Definition: This calculator determines the pressure drop in a pipe based on fluid viscosity, pipe dimensions, and flow rate using the Hagen-Poiseuille equation.

Purpose: It helps engineers and fluid system designers analyze pressure requirements in piping systems.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \Delta P = \frac{8 \times \mu \times L \times Q}{\pi \times r^4} \]

Where:

Explanation: The formula relates pressure drop to flow characteristics in laminar flow through cylindrical pipes.

3. Importance of Pressure Calculation

Details: Accurate pressure drop calculations ensure proper pump sizing, system efficiency, and prevent flow-related issues in piping systems.

4. Using the Calculator

Tips: Enter viscosity in Pa·s (water at 20°C ≈ 0.001 Pa·s), pipe length in meters, flow rate in m³/s, and pipe radius in meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What flow regime does this formula apply to?
A: The Hagen-Poiseuille equation applies only to laminar flow (Re < 2100).

Q2: How does pipe radius affect pressure?
A: Pressure drop is inversely proportional to the fourth power of radius - small radius changes have large effects.

Q3: What's a typical viscosity value for water?
A: Water at 20°C has viscosity of about 0.001 Pa·s (1 centipoise).

Q4: Can I use diameter instead of radius?
A: Yes, but remember to use radius = diameter/2 in the calculation.

Q5: What about turbulent flow?
A: For turbulent flow, you would need to use the Darcy-Weisbach equation instead.

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