Pumps, valves, probes, fittings, tubing and sensing components for precise sample preparation, reagent handling and instrument fluidics.
Gas-Liquid Diaphragm Pumps for Analyzer Waste Aspiration
Application guide · Waste aspiration
Waste aspiration after needle, cup or plate washing often carries air, droplets and foam. A gas-liquid diaphragm pump can create suction and tolerate the mixed stream, while a flooded liquid pump is more appropriate for a continuously liquid-filled transfer path.
Engineering example: a station receiving 5 mL wash liquid in 2 seconds produces a 150 mL/min liquid pulse before aspirated air is counted. The waste design must clear that pulse, the common manifold and any foam without overflowing; nominal gas free flow is not a liquid drain rating.[1][2]
01Define the liquid, receiver and complete duty before selecting the component
Translate the analytical task into an engineering duty
Use case
Inputs to define
Decision supported
Direct mixed aspiration
Liquid pulse, air fraction, lift and foam
Use gas-liquid path and verify separator/waste vessel
Vacuum-over-liquid collection
Vessel volume, vacuum setpoint and evacuation rate
Keep liquid out of the gas pump with level protection
Flooded liquid transfer
Continuous liquid at inlet
Use DPL liquid pump rather than DPGL800
02Calculate the working point and the margin the instrument really needs
Calculations to complete before prototype selection
Quantity
How to define it
Why it matters
Liquid generation
wash volume ÷ pulse time
Sets minimum drain requirement
Vessel reserve
maximum concurrent waste + foam + sensor margin
Prevents liquid carryover
Recovery time
vacuum volume and leakage versus pump curve
Determines cycle readiness
Use minimum, routine and maximum conditions rather than one nominal point. Include the first cycle after priming or idle, the lowest source level, the highest expected restriction and the actual receiving geometry. A nominal capacity, free-flow value or theoretical command increment is not an acceptance result.
03Map the task to a FOREACH configuration and the rest of the fluid path
04Program the full liquid cycle, including prime, wash and recovery
Start before wash pulse→Aspirate air/liquid mixture→Separate or collect waste→Continue until line clears→Stop with backflow control→Alarm on full vessel or lost vacuum
A complete method cycle is more than the active delivery step
The exact physical order and parallel actions depend on the instrument. Retain each state in the control and verification plan.
Record valve states, motion, dwell, sensor windows and rejected recovery cycles. This makes throughput and liquid consumption auditable and prevents a fast component movement from being reported as the complete analyzer cycle.
05Design abnormal-state diagnosis before the fault occurs
Observed result, likely mechanism and useful next action
Observed condition
Likely mechanism
Engineering response
Foam enters downstream
Insufficient vessel volume or separator
Increase reserve and add protection
Wash station overflows
Waste capacity/timing below supply
Start earlier or increase installed aspiration
Vacuum never recovers
Leak, open valve or saturated filter
Isolate branches and trend pressure
The controller should distinguish a recoverable event from a result-invalidating event. A retry is useful only after the original cause has been removed and the liquid path has returned to a verified state.
06Accept performance where the liquid is actually used
Minimum qualification plan for the integrated channel
Result
Where or how to measure
Acceptance question
Clearance time
Highest station and maximum liquid pulse
No residual overflow
Vacuum recovery
After repeated cycles and near-full vessel
Ready before next wash
Protection
Full vessel, blocked filter and power loss
No liquid reaches protected gas path
Test the exact liquid and complete wetted path at minimum, routine and maximum conditions.
Separate first-cycle, steady-state and post-idle results; do not average away recovery behavior.
Challenge the relevant fault and confirm the controller prevents an invalid result from being accepted.
Retain the configuration, software sequence, consumables and receiving-position result together as the qualification record.
