Water Pressure Loss Calculator

Darcy-Weisbach Equation:

\[ PL = \frac{f \cdot L \cdot V^2}{2 \cdot D \cdot g} \]

Friction Factor (f):

dimensionless

Length (L):

meters

Velocity (V):

m/s

Diameter (D):

meters

Gravity (g):

m/s²

Pressure Loss (PL):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Darcy-Weisbach Equation?

The Darcy-Weisbach equation is a fundamental equation in fluid mechanics used to calculate the pressure loss (head loss) due to friction along a given length of pipe with a constant flow rate. It's widely used in hydraulic engineering for pipe flow calculations.

2. How Does the Calculator Work?

The calculator uses the Darcy-Weisbach equation:

\[ PL = \frac{f \cdot L \cdot V^2}{2 \cdot D \cdot g} \]

Where:

\( f \) — Friction factor (dimensionless)
\( L \) — Length of pipe (meters)
\( V \) — Flow velocity (m/s)
\( D \) — Pipe diameter (meters)
\( g \) — Gravitational acceleration (m/s²)
\( PL \) — Pressure loss (meters of fluid)

Explanation: The equation calculates the energy loss due to friction in a pipe, expressed as the height of a fluid column (head loss).

3. Importance of Pressure Loss Calculation

Details: Accurate pressure loss calculation is crucial for designing piping systems, selecting appropriate pump sizes, ensuring adequate flow rates, and optimizing energy efficiency in fluid transport systems.

4. Using the Calculator

Tips: Enter all values in the specified units. The friction factor depends on pipe material and flow conditions (typically 0.01-0.05 for turbulent flow). Standard gravity is 9.81 m/s².

5. Frequently Asked Questions (FAQ)

Q1: How do I determine the friction factor?
A: The friction factor depends on Reynolds number and pipe roughness. For turbulent flow, use Moody chart or Colebrook-White equation. For laminar flow, f = 64/Re.

Q2: What are typical friction factor values?
A: For smooth pipes: 0.01-0.02; for commercial steel: 0.02-0.03; for rough pipes: up to 0.05 or higher.

Q3: Can this calculator be used for any fluid?
A: Yes, the equation works for any Newtonian fluid, but the result is in meters of that fluid (density is accounted for in the friction factor).

Q4: What if I have multiple pipe segments?
A: Calculate pressure loss for each segment separately and sum them for the total system loss.

Q5: How does pipe diameter affect pressure loss?
A: Pressure loss is inversely proportional to pipe diameter. Doubling the diameter reduces pressure loss by a factor of approximately 32 for the same flow rate.