# Pump Volumetric Efficiency

on . Posted in Fluid Dynamics

Pump volumetric efficiency, abbreviated as $$\eta_{pv}$$, a dimensionless number, specifically refers to this concept in the context of positive displacement pumps, such as those used in hydraulic systems or certain types of compressors.  In the case of a positive displacement pump, volumetric efficiency is the ratio of the actual flow rate of fluid delivered by the pump to the theoretical maximum flow rate it could deliver under ideal conditions.  The ideal conditions assume that there is no leakage, and the pump operates without any internal losses or inefficiencies.

A pump with high volumetric efficiency is more effective in transferring fluid and is generally more desirable in various applications.  Factors such as clearances, seal efficiency, and friction within the pump can affect its volumetric efficiency.  Engineers aim to design pumps with high volumetric efficiency to maximize their performance and minimize energy consumption.

### Pump Volumetric Efficiency Formula

$$\eta_{pv} \;=\; ( V_a \;/\; V_i ) \;100$$     (Pump Volumetric Efficiency)

$$V_a \;=\; \eta_{pv} \; V_i \;/\; 100$$

$$V_i \;=\; V_a \; 100 \;/\; \eta_{pv}$$

Symbol English Metric
$$\eta_{pv}$$  (Greek symbol eta) = pump volumetric efficiency $$dimensionless$$
$$V_a$$ = actual displacement volume $$in^3$$ $$mm^3$$
$$V_i$$ = ideal displacement volume $$in^3$$ $$mm^3$$

Tags: Pump Efficiency