Locate the source, drive and receiving position for this task
Define actual flow, cumulative volume, allowable flow interruptions, backpressure, refills and operating duration. Follow the diagram to confirm liquid contact, pressure and destination before assigning drive and connection roles.
Shortlist by displacement, speed and installed load
Define dose or flow, allowable fluctuation, backpressure and duty cycle before selecting a configuration. Displacement per revolution multiplied by speed estimates nominal flow, which requires confirmation with the actual liquid, tubing and outlet conditions.
| Condition to compare | Information required | Selection affected |
|---|---|---|
| Displacement and speed | Target dose or flow and available cycle time | Compare displacement, speed and control range |
| Installed load | Inlet, backpressure, tubing and liquid properties | Confirm the actual operating point |
| Start/stop mode | Continuous, dose-by-dose or intermittent operation | Define steady-state and startup acceptance separately |
Compare product options against task requirements
The following candidate options match this page's responsibilities. Compare them against the operating conditions described, then check capacity, materials and interfaces on the product pages. Card images show representative configurations; suitability must still be confirmed at actual operating points and by application results.
| Product category | Corresponding role | Confirm before selection |
|---|---|---|
| RPL Valveless Metering Pump | Suitable repeated or continuous metering | Compare displacement, speed, actual backpressure and starts/stops; check two-stream ratios separately |
Assess steady operation separately from start-stop recovery
After priming, run the specified speed and cycle, recording continuous operation and starts/stops separately. Check initial output after bottle changes, extended shutdown or formulation changes. Do not apply steady-operation parameters directly to startup.
Action records should link commands, valve or interface states and actual received results. When raw material, container or sample identity changes, reconfirm shared paths and conditions permitting the next step. Completion of drive movement alone does not replace task acceptance.
Distinguish individual doses, time-window volumes and cumulative volumes
For discrete tasks, measure first, middle and last doses. For continuous tasks, measure flow within time windows and cumulative volume. If serving an analytical method, also check mixing, baseline or reaction results; component metering specifications do not directly establish method acceptance.
| Validation scenario | Measurement or observation | Interpretation and action |
|---|---|---|
| Discrete doses | Measure startup doses and successive doses | Steady flow does not replace validation of each delivered dose |
| Continuous supply | Check short-term changes and cumulative volume | Investigate fluctuations and cumulative errors separately |
Record test medium, configuration, installed path and operating sequence; present routine operating points and boundary results separately. Calculations support design discussions, component documentation checks models, and installed measurements confirm the actual task.
After an abnormality or maintenance, first identify which segment needs recovery
An empty source, bubbles, slip, pressure changes or resets can disturb sustained output. Reconcile undelivered volume and process state before restarting to avoid duplicate additions.
Retain current source, container identity, completed actions, valve or interface state and actual receiving information. Use the table to locate the stage that changed before deciding to retry, continue or restart. After recovery, recheck the relevant operating point before returning an uncertain action to the automatic cycle.
Continue with tasks on the same branch
- Repeated Dispensing with Valveless Pumps: Displacement, Start-Stop Behavior and Nozzle Droplets
- Valveless-pump titration: when to use bulk addition and when fine metering is needed
- Carrier and Flow-Cell Supply: Installed Flow, Bubbles and Baseline
- Dual-Stream Proportioning: Cumulative Ratio and Instantaneous Mixing