Differential pressure flowmeters inferentially measure the flow of liquids, gases and vapor, such as water, cryogenic liquids, chemicals, air, industrial gases, and steam. Be careful using differential pressure flowmeters for fluids with high viscosity, such as some hydrocarbons and foods, because their accuracy can be degraded when Reynolds number is low.

This flowmeter can be applied to relatively clean fluids. With proper attention to materials of construction, the flow of corrosive fluids, such as are found in the chemical industry, can be measured.

Somewhat dirty fluids can be measured by purging the impulse piping with an inert fluid. Be careful when using differential pressure flowmeters in dirty services because the dirt can plug the impulse piping and cause incorrect measurements. Diaphragm seals can sometimes be applied in these applications. However one should remember that diaphragm seals can degrade the performance of the differential pressure transmitter system, and hence, the degrade the performance of the flow measurement system.

Differential pressure flowmeters are generally applicable to many flows in most industries, such as mining, mineral processing, pulp and paper, petroleum, chemical, petrochemical, water, and wastewater industries. Other flow measurement technologies may perform better than differential pressure flowmeters in many applications, however differential pressure flowmeters are still used extensively due to long-standing user familiarity with the technology.