Roots blowers are commonly referred to as air blowers or PD (positive displacement) blowers.
Gravity acts as drain pump, and aeration is accomplished through thin-filming and positive displacement of air as it is forced out of the root zone by water.
The traditional two-stroke design relies upon a mechanically driven positive displacement blower to charge the cylinders with air before compression and ignition.
Most hand pumps have plungers or reciprocating pistons, and are positive displacement.
Positive Displacement Pump Fillers: positive displacement, pump filling machines easily handle a wide range of container sizes, fill volumes and product types.
We accept the use of positive displacement and turbine meters for revenue accounting.
Gear pumps are positive displacement (or fixed displacement), meaning they pump a constant amount of fluid for each revolution.
There are two main types of superchargers defined according to the method of compression: positive displacement and dynamic compressors.
Compared to centrifugal pumps, positive displacements (PD) pumps have several advantages.