Differential pressure (DP) flow meters are widely used to measure the flow rate of fluids, including gases, liquids, and steam, in pipelines. The basic operating principle behind these devices is that as a fluid flows through a constriction, the pressure drops in proportion to the square of the flow velocity. This pressure difference is then used to calculate the flow rate. Below, we’ll explore the working principle of differential pressure flow meter.

A differential pressure flow meter works by creating a controlled restriction in the flow path and measuring the pressure drop across it.

• When a fluid passes through a constriction, its velocity increases and static pressure decreases.
• The difference in pressure between the upstream and downstream sides of the constriction is proportional to the flow rate.
• By measuring this differential pressure and knowing the geometry of the primary element, the flow rate can be calculated.