MACHINES VOLUMETRIQUES BAC III ELM

This document is an instructional chapter on the performance of positive displacement (volumetric) pumps and the factors that influence it. It first examines the physical properties of liquids—viscosity (dynamic and kinematic), lubricity/onctuosity, volatility, corrosion, and abrasion—and explains how each property affects pump operation, wear, and compatibility. It then analyzes key mechanical factors such as rotational or translational speed, torque, operating and test pressures, and temperature, emphasizing their limits, interdependence, and impact on pump sizing, safety, and reliability. Finally, it discusses sealing (static and dynamic) and presents common sealing solutions—baffles, packing glands, O-rings, and lip seals—along with their operating ranges, advantages, limitations, and suitability depending on the fluid and service conditions.