Locate the source, drive and receiving position for this task
Required inputs are target flow and backpressure for each path, startup delays, permitted composition variation and the merging/mixing path. Confirm liquid contact, pressure and destination along each illustrated section before defining drive and connection responsibilities.
Establish a nominal ratio from each stream's displacement and speed
Establish the nominal ratio from each path's target volume, displacement and speed, and check adjustment range and actual backpressure. An acceptable cumulative ratio does not ensure stable composition over short intervals. Specify mixing location and volume too.
| Condition to compare | Information required | Selection affected |
|---|---|---|
| Nominal ratio | Displacement, speed and target flow for each branch | Define initial ratio-selection criteria |
| Dynamic proportioning | Backpressure, startup and supply-loss conditions for both paths | Check for deviations in instantaneous composition |
| Mixing path | Junction position, hold-up volume and outlet load | Define uniformity and response time |
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 |
Prime branches separately and record low-liquid events and switching
Prime each stream separately, start and switch according to the program, and record inlet, outlet and cumulative volumes. If one stream runs empty or its load changes, identify potentially affected mixed liquid rather than continuing to total commanded volume.
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.
Validate cumulative ratio and mixed composition
Measure each stream's actual volume and mixed composition during startup, shutdown and ratio changes. Distinguish output error from insufficient mixing, using formulation-relevant tests to verify the received liquid.
| Validation scenario | Measurement or observation | Interpretation and action |
|---|---|---|
| Cumulative ratio | Collect and compare the two branch volumes separately | Control average ratio and locate single-stream deviations |
| Outlet composition | Include startup, liquid changes and restart after supply loss | An acceptable cumulative ratio cannot replace instantaneous mixing validation |
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
Different loads or unsynchronized starts/stops can produce an acceptable cumulative ratio while instantaneous composition is incorrect. Recheck actual results from affected steps before resuming the next action.
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
- Valveless metering pumps: operating conditions for repeated dispensing and continuous supply
- 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