Engineering editorial · Updated 2026-09-18
The short answer
Required flow comes from the process, while the pump must deliver that flow against the system resistance.
What to check
Separate free-flow capacity from working flow. Check branches, valves and filters, and allow for the change in resistance as filters load.
Make the comparison meaningful
Record supply voltage, medium temperature, circuit arrangement and the measurement location. Compare candidate pumps under the same conditions. Maximum flow, maximum pressure and a single noise value do not describe a complete working point.
Before you choose a model
Ask for the current specification, performance curve and approved operating limits for the exact variant. Agree on the test method and acceptance criteria, then validate a sample in your equipment. This guide describes selection principles, not verified performance for a Shan Neng model.