Differential Pressure Calculator
Calculate differential pressure and flow rate in fluid systems using flow factor and specific gravity
Differential Pressure Calculation
Calculation Mode
Select fluid or use custom specific gravity
Relative density compared to water
Volumetric flow rate through the system
Flow coefficient of the valve or constriction
Pressure difference across the flow constriction
Calculation Results
Differential Pressure
Input Parameters
Formula used: ΔP = (Q²/Kv²) × S
Where: ΔP = differential pressure, Q = flow rate, Kv = flow factor, S = specific gravity
System Analysis
Example Calculation
Water Flow Example
Fluid: Water (specific gravity = 1.0)
Flow rate: 10 L/min
Flow factor: 5 L/min
Goal: Find differential pressure
Calculation Steps
1. Convert to consistent units: Q = 10 L/min, Kv = 5 L/min
2. Apply formula: ΔP = (Q²/Kv²) × S
3. ΔP = (10²/5²) × 1 = (100/25) × 1 = 4
Result: ΔP = 4 bar
Common Fluid Properties
Water
SG = 1.0
Standard reference fluid
Light Oil
SG = 0.8 - 0.9
Common petroleum products
Heavy Liquids
SG = 1.2 - 13.6
Glycerin, mercury, etc.
Gases
SG ≈ 0.001
At standard conditions
Applications
Flow Measurement
Orifice plates, venturi meters
System Monitoring
Detect blockages and leaks
Control Systems
Pressure switches and valves
HVAC Systems
Air flow measurement
Calculation Tips
Ensure consistent units for flow rate and flow factor
Use accurate specific gravity values for your fluid
Consider temperature effects on fluid properties
Verify flow factor from manufacturer specifications
Understanding Differential Pressure
What is Differential Pressure?
Differential pressure is the pressure difference between two points in a fluid system. It occurs when fluid flows through constrictions such as orifices, venturi meters, valves, or other flow control devices.
Key Applications
- •Flow rate measurement in pipelines
- •Leak and blockage detection
- •HVAC system monitoring
- •Medical device flow control
Mathematical Relationships
ΔP = (Q²/Kv²) × S
Q = Kv × √(ΔP/S)
- ΔP: Differential pressure
- Q: Volumetric flow rate
- Kv: Flow factor (flow coefficient)
- S: Specific gravity of fluid
Note: Flow factor represents the efficiency of flow through the restriction
Measurement Methods
Orifice Plates
Simple, cost-effective flow measurement
High pressure drop, good accuracy
Venturi Meters
Low pressure loss, high accuracy
More expensive, excellent for continuous use
Pitot Tubes
Point velocity measurement
Common in aviation and HVAC applications