Flow measurement probe - Differential pressure measurement

Differential pressure-based flow measurement: an overview of deltaflow

The deltaflow differential pressure (dp) flowmeter is a cost and energy efficient flowmeter for measuring gases, liquids and steam.

Thanks to its special probe profile, the deltaflow Pitot tube guarantees the highest level of accuracy and excellent process reliability, even under extreme conditions. Averaging Pitot tubes cause the lowest pressure drop of all dp-flow meters and are therefore extremely energy efficient.

The deltaflow differential pressure flowmeter is already used in tens of thousands of applications in many areas of industrial technology.

Compared to conventional ISO 5167 primary elements such as orifices or venturi tubes, the deltaflow gas flow meter not only saves energy, but is also cheaper and results in lower installation costs. The high tolerance of the deltaflow ensures high accuracy even in non-ideal flow profiles, even when the probe has to be placed at a short distance from the valve or elbow pipes.

Typical applications include vapour flow measurement, compressed air measurement, and liquid flow measurement of water, oil and benzene. The deltaflow is used to measure chimney gas and flue gas, natural gas, biogas and many more...

Deltaflow averaging pitot tubes are used in thousands of industrial plants, such as power plants, wastewater treatment plants, breweries, car factories, steel mills... A free download of a self-descriptive software is available for the calculation and design of deltaflow flow meters.

Measurement characteristics:

Key indicators: 

• Low pressure loss, resulting in significant energy savings
• Easy installation, no need to disconnect piping
• Low weight even for large diameters
• Extremely high accuracy (0.4%)
• Extremely wide measuring range, up to 1:30 depending on the application
• Excellent resistance to dirt and condensation
• Low purchase cost, even for large diameters
• A proven operating principle

Flow measurement with a deltaflow pitot tube is based on the same principles as conventional primary measuring elements (measuring flange, venturi tube, nozzle), so it is easy to integrate electronically or to integrate into the DCS.

The deltaflow is also ideal for measuring the flow of highly contaminated gases: the optimised measurement profile increases the flow rate locally by a factor of 2.5 in the pipe, thus sucking dust away from the sensor openings. The deltaflow reliably and accurately measures most dry dust up to a particle load of 100 mg/m³.

For higher loads or sticky dusts, use the LSP air purification unit:

The LSP is connected between the deltaflow and the differential pressure transducer and automatically purges the probe with compressed air at adjustable intervals.
This keeps the probe dust-free and ensures accurate measurement results.