Locate the task in the fluid path first
Arrows indicate task relationships, not that every component is connected in series in one tube. Check valve positions, pump wetted boundaries and operating states for each branch.
For each feed, record mode, actual medium and cumulative volume. For each sample, record collected material, discarded volume and process-volume disturbance. Validate valve isolation, cleaning or sterilization, and backflow after shutoff separately.
Common product roles and application guides
| Product category | Role in this instrument |
|---|---|
| Syringe pump | Pulse feeding and discrete sampling |
| Valveless metering pumps | Repeated or continuous feeding in suitable configurations |
| Diaphragm pump | Suitable air-containing waste aspiration |
| Fluidic valves | Routing for feeding, sampling and maintenance; tubing shutoff in feed or sample branches |
| Bubble and pressure detection | Branch-status signals for process records |
| Tubing and fittings | Connect feed sources, cultures and sample destinations |
Operating requirements differ by step
| Stage | Task category | Operating conditions to define |
|---|---|---|
| Feeding: distinguish pulse and continuous modes | Feed mode and cumulative material balance | Discrete or continuous feeding mode, time profile, medium, load, cumulative volume and permissible interruption |
| Sampling: account for representativeness and discard volume | Sample renewal and representativeness | Analyte, sampling interval, renewal of stagnant sections, discard-volume budget and permitted pretreatment |
| Path isolation: prevent unintended connections to culture vessels | Valve-path requirements | All ports, valve states, pressures in each state, shared volume and flushing volume |
| Waste removal: specify biomass and foam conditions | Actual drainage and vessel condition | Liquid or gas-liquid inlet conditions, peak incoming flow, allowable accumulation, lift and waste container |
| Monitoring: incorporate fluid-path information into process records | Inputs for fault detection | Specific sensor configuration, location, liquid/tubing, sampling rate, threshold and time window |
Feeding: distinguish pulse and continuous modes
Adding the same cumulative volume at different times may alter the process. Translate batch, periodic-pulse or continuous requirements into allowable variation and interruptions before comparing drives.
Sampling: account for representativeness and discard volume
Renewing stagnant sections consumes liquid; small systems especially need a volume budget. Use paired sample analysis and reactor-volume records together to assess sampling.
Path isolation: prevent unintended connections to culture vessels
The port-state table must cover feeding, sampling, cleaning and drainage. Check leakage and backflow even in closed states.
Waste removal: specify biomass and foam conditions
Confirm suitable conditions separately for air-containing aspiration and liquid-only drainage. After maintenance, check sealing and isolation before resuming culture operations.
Monitoring: incorporate fluid-path information into process records
Pressure and bubble alarms help assess branch anomalies; culture condition requires the relevant process measurements. Preserve cumulative-volume records through actual recovery procedures.
Explore configurations through product application guides
Validate the complete cycle through application results
Check cumulative feeding, sampling representativeness, volume balance and recovery during long runs.
| Step to validate | Measurements or observations | Priority troubleshooting checks |
|---|---|---|
| Feeding: distinguish pulse and continuous modes | Measure pulse doses or flow over defined time windows separately, then reconcile cumulative material, bottle changes and restarts. | An empty source, bubbles, refill interruptions or repeated control states may alter actual feed delivery. |
| Sampling: account for representativeness and discard volume | Measure renewal time at the analytical or receiving interface and assess target representativeness using paired samples | Old-sample mixing, settling, adsorption or insufficient renewal time can make the sample unrepresentative of its source. |
| Path isolation: prevent unintended connections to culture vessels | Check unintended connections, leakage, backflow and post-switching residue in each state; measure flushing volume and arrival delay through the complete path | Misalignment, shared-segment residue or abnormal switching pressure may affect the next task |
| Waste removal: specify biomass and foam conditions | Test emptying, liquid accumulation and interlocks after a full-vessel or blockage condition using the actual incoming liquid. | Leaks, foam, blockages or a full container can reduce actual drainage capacity. |
| Monitoring: incorporate fluid-path information into process records | Measure fault detection, false alarms and end-to-end response separately; cover baseline changes with liquid, speed and operating conditions | Normal air segments, viscosity changes and sampling delays may be misclassified |
Bubble and pressure signals describe fluid-path conditions; they do not directly measure pH, dissolved oxygen or growth. Validate the complete aseptic boundary separately.
Common selection and recovery questions
Does equal cumulative feed volume establish an equivalent feeding process?
Also compare addition timing, pulsed or continuous mode, permitted fluctuation and no-flow intervals. Validate individual doses or time-window flow first, then cumulative volume and process results.
Does sampling consumption equal only the volume collected in the analytical vessel?
Record path-renewal discard and other drainage together. Confirm any permitted return path, then check actual process volume and sample representativeness.
References
View references (4)
- [1]FOREACH syringe pumps: configurations and specifications
- [2]FOREACH RPL / DRPL valveless metering pumps: configurations and specifications
- [3]FOREACH Tubing-Pinch Options, Discussed by Project: Configurations and Specifications
- [4]FOREACH bubble / pressure detection: configurations and specifications