Oval Gear (Positive Displacement)

FLOW

Positive displacement flowmeters, or PD meters, feature two precisely machined intermeshing gears which rotate within a measuring chamber to determine the volumetric liquid flow rate by counting the number of the gears’ rotations. The PD meter functions in much the same manner as a positive displacement pump with the exception being that in the PD pump the gears drive the fluid media, whereas in the PD flowmeter the fluid media drives the gears. The positive displacement technique is one of the oldest flow measurement technologies in existence and has been in use for over one hundred years. These meters are all characterized by high accuracy (up to ±0.1% of reading), good repeatability (up to 0.05% of reading), wide turndown ratios of up to 100:1, and the ability to maintain this level of performance for both high viscosity and changing-viscosity fluid media.

Oval gear flowmeters are categorised as positive displacement flow technology. When liquid flows through this type of positive displacement flowmeter, two oval geared rotors measure a constant volume per rotation within a precisely machined measuring chamber. With each rotation, a constant volume of liquid is measured.