FieldengFluid & Pressure
Flow from Differential Pressure
Estimate flow from ΔP across an orifice, a known K, or a valve Cv. Pick the model explicitly.
Fluid & PressureInstrumentation & Controls
Estimate flow from ΔP across an orifice, a known K, or a valve Cv. Pick the model explicitly.
App id: FLUID-23. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
orifice Q = Cd A √(2ΔP/ρ); K: v = √(2ΔP/(Kρ)); Cv: Q = Cv √(ΔP/SG)Inputs
| Name | Unit |
|---|---|
| Model (0=orifice, 1=K, 2=Cv) | 1 |
| Differential pressure (camera) | kPa |
| Density (optional) | kg/m3 |
| Orifice / throat diameter (optional) | mm |
| Discharge coefficient Cd (optional) | 1 |
| Loss coefficient K (optional) | 1 |
| Valve Cv (optional) | 1 |
| Specific gravity (optional) | 1 |
Outputs
| Name | Unit |
|---|---|
| Volumetric flow (hero result) | m3/s |
| Throat velocity | m/s |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
Every result | US Cv convention | info |
Cd > 1 | Discharge coefficient above 1 | caution |
Cd ≤ 1 | Incompressible orifice estimate | info |
Assumptions
- Cv path uses US gpm/psi and does not report a throat velocity.
- Not a compressible-gas or custody-transfer meter calculation.
Provenance
- Same incompressible relations as the orifice, minor-loss, and valve-Cv tools. Model is not inferred.