Pressure drop across any device that presents a restriction in the flow stream should be considered when calculating the permanent pressure loss in a flow loop. This can have a significant effect with some designs, but the Enhanced Floating Rotor (EFR) design PRECISION TURBINE FLOWMETER (PFT) minimizes pressure drop due to the small areas required for the cone and rotor components of the flowmeter.
Pressure drop at recommended nominal flow rate of any size PTF utilizing the EFR design is not significant and usually in the 1 psid range. Pressure drops above the 6 psid range should be avoided due to exceeding the linear measurement range of the meter, which can impact performance and cause damage to the device.