1. What is a Pressure in Pipe Calculator?

Definition: This calculator estimates 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 technicians determine the pressure loss in laminar flow conditions through cylindrical pipes.

2. How Does the Calculator Work?

The calculator uses the Hagen-Poiseuille equation:

Where:

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

Explanation: The equation relates pressure drop to the fourth power of pipe radius, making pipe diameter particularly important in pressure loss calculations.

3. Importance of Pressure Drop Calculation

Details: Accurate pressure drop calculations are essential for proper pump selection, system design, and ensuring adequate flow rates in piping systems.

4. Using the Calculator

Tips: Enter the fluid viscosity, pipe length, flow rate, and pipe radius. All values must be > 0. Note that this calculator assumes laminar flow conditions (Re < 2100).

5. Frequently Asked Questions (FAQ)

Q1: What is dynamic viscosity?
A: Dynamic viscosity measures a fluid's resistance to flow. Water at 20°C has μ ≈ 0.001 Pa·s, while honey has μ ≈ 10 Pa·s.

Q2: Does this work for turbulent flow?
A: No, this equation is only valid for laminar flow. For turbulent flow, you would use the Darcy-Weisbach equation.

Q3: Why is radius to the 4th power?
A: The strong dependence on radius shows that small changes in pipe diameter dramatically affect pressure drop.

Q4: What are typical pipe radius values?
A: Domestic water pipes might have radii of 0.005-0.015m, while industrial pipes can be much larger.

Q5: How do I convert the result to other units?
A: 1 Pa = 0.000145 psi, or 1 kPa = 0.01 bar. You may need to convert based on your preferred units.