DP Level & Flow
What this tool does
Volumetric and mass flow from differential pressure for an orifice, venturi, or pitot. This page says what the tool is for, in plain language. The working formula stays on the signed-in tool.
When to use it
Open DP flow when this is the job: Volumetric and mass flow from differential pressure for an orifice, venturi, or pitot. That is usually a level or flow calibration, a bore check, or a valve you are about to size.
Step-by-step
- Open DP flow from the tool list.
- Fill Device, Fluid, Units, Differential pressure from the instrument, the drawing, or the job record. Use the unit shown beside each field.
- Fill the remaining fields the same way. Skip a field only when the screen marks it optional.
- Run Calculate when that control is on the page, then read every result row and any warning.
- Check the result against the site procedure and the manufacturer data before you change a range, a wire, a setpoint, or a weight.
- This help page is public. Opening the tool still requires a Pro session.
Inputs
- Device
- Choose the Device that matches the instrument, the drawing, or the job. Choices include Orifice plate, Venturi, Pitot.
- Fluid
- Choose the Fluid that matches the instrument, the drawing, or the job. Choices include Liquid, Gas.
- Units
- Imperial or metric. Pick one and enter every other field in that system.
- Differential pressure
- Differential pressure is the value you read from the instrument, the drawing, or the job record. Enter it in inH2O.
- Differential span
- Differential span is the value you read from the instrument, the drawing, or the job record. Enter it in inH2O.
- Pipe diameter
- Pipe diameter is the value you read from the instrument, the drawing, or the job record. Enter it in in.
- Bore
- Bore is the value you read from the instrument, the drawing, or the job record. Enter it in in.
- Discharge coefficient
- Discharge coefficient is the value you read from the instrument, the drawing, or the job record.
- Density
- Density is the value you read from the instrument, the drawing, or the job record. Enter it in lb/ft³.
- Isentropic exponent
- Isentropic exponent is the value you read from the instrument, the drawing, or the job record.
- Upstream absolute pressure
- Upstream absolute pressure is the value you read from the instrument, the drawing, or the job record. Enter it in psia.
Results
- Result
- The reported value for DP flow. Use the unit printed on that row.
- Warnings
- A warning means an entry is incomplete or outside what this tool will stand behind. Recheck the inputs and the site procedure.
Common mistakes
- Using the wrong specific gravity, or forgetting a wet leg, a seal fill, or a blanket pressure.
- Mixing a head unit with a pressure unit without reading the unit on the screen.
- Sizing from a flow or a differential that is not the one in the line.
- Do not treat a result from DP flow as a substitute for the site procedure or the manufacturer data.
Standards references
These are the standards and public references named on this tool. Clause numbers appear only when the catalog already cites them.
- ISO 5167-1 mass-flow equation
- ISO 5167-2 orifice expansibility
- ISO 5167-4 Venturi expansibility
- ISO 3966 pitot coefficient with Bernoulli
Offline and access
This engine can run offline after the server has cached it for the signed-in account.
A free session can read this help page. The tool card shows the name and the short summary. Opening the tool requires Pro.