Pressure vs Flow Rate Calculator

Flow Rate Formulas:

\[ V = \sqrt{\frac{2 \times (P_1 - P_2) \times 144}{\rho}} \] \[ Q = V \times A \times 448.83 \]

Inlet Pressure (P₁):

psi

Outlet Pressure (P₂):

psi

Fluid Density (ρ):

lb/ft³

Pipe Area (A):

ft²

Velocity (V): ft/s

Flow Rate (Q): GPM

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1. What is a Pressure vs Flow Rate Calculator?

Definition: This calculator determines fluid velocity and flow rate through a pipe based on pressure difference, fluid density, and pipe cross-sectional area.

Purpose: It helps engineers and technicians analyze fluid systems and design piping networks.

2. How Does the Calculator Work?

The calculator uses these formulas:

\[ V = \sqrt{\frac{2 \times (P_1 - P_2) \times 144}{\rho}} \] \[ Q = V \times A \times 448.83 \]

Where:

\( V \) — Fluid velocity (ft/s)
\( P_1 \) — Inlet pressure (psi)
\( P_2 \) — Outlet pressure (psi)
\( \rho \) — Fluid density (lb/ft³)
\( Q \) — Flow rate (GPM)
\( A \) — Pipe cross-sectional area (ft²)

Explanation: The pressure difference drives the flow, with velocity calculated from the Bernoulli equation and flow rate derived from velocity and area.

3. Importance of Pressure-Flow Calculations

Details: Accurate calculations ensure proper system design, pump sizing, and prevent issues like cavitation or excessive pressure drops.

4. Using the Calculator

Tips: Enter pressures in psi (P₁ > P₂), fluid density (default 62.4 lb/ft³ for water), and pipe area in square feet. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What does the 144 factor represent?
A: It converts psi (lb/in²) to lb/ft² (1 ft² = 144 in²).

Q2: Why 448.83 in the flow rate formula?
A: This converts ft³/s to gallons per minute (1 ft³/s = 448.83 GPM).

Q3: What's a typical water density value?
A: Pure water at 60°F is 62.37 lb/ft³, often rounded to 62.4 lb/ft³.

Q4: How do I calculate pipe area?
A: For circular pipes: \( A = \pi \times (D/2)^2 \) where D is diameter in feet.

Q5: Does this account for friction losses?
A: No, this is ideal flow. For real systems, consider additional pressure drop calculations.