1. What is a Cv to Flow Calculator?

Definition: This calculator determines the flow rate through a valve based on its flow coefficient (C_v), pressure drop, and fluid specific gravity.

Purpose: It helps engineers and technicians size valves and predict flow rates in fluid systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM)
• \( C_v \) — Valve flow coefficient (dimensionless)
• \( \Delta P \) — Pressure drop across valve (psi)
• \( SG \) — Specific gravity of fluid (dimensionless)

Explanation: The flow rate is directly proportional to the C_v value and the square root of the pressure to specific gravity ratio.

3. Importance of Cv Flow Calculation

Details: Proper valve sizing ensures efficient system operation, prevents cavitation, and maintains desired flow characteristics.

4. Using the Calculator

Tips: Enter the valve C_v (from manufacturer specs), pressure drop across valve, and fluid specific gravity (default 1.0 for water). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical C_v value?
A: C_v varies by valve size and type - from 1-5 for small valves to over 1000 for large industrial valves.

Q2: How is C_v defined?
A: C_v is the flow in GPM of 60°F water that produces 1 psi pressure drop across the valve.

Q3: What's the specific gravity of common fluids?
A: Water=1.0, Gasoline=0.72, SAE 30 Oil=0.89, Seawater=1.03.

Q4: Does this work for gases?
A: No, this formula is for liquids only. Gas flow requires different calculations.

Q5: What if my pressure drop is too high?
A: High ΔP may cause cavitation. Consider a valve with higher C_v or system modifications.