Pumps, valves, probes, fittings, tubing and sensing components for precise sample preparation, reagent handling and instrument fluidics.
Liquid Diaphragm Pumps for Wash Delivery and Priming
Application guide · Washing and priming
Wash delivery and priming require a defined amount of cleaning liquid to reach one or several probes within a fixed time. The pump is selected at the installed pressure loss through reservoir pickup, valves, tubing, manifolds and wash openings—not at its unrestricted free-flow point.
Engineering example: delivering 10 mL in 3 seconds requires an average installed flow of 200 mL/min. If two branches wash simultaneously, the total pump duty and the permitted branch imbalance must be stated; a 300 mL/min free-flow label alone does not prove the result.[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
Probe wash
Volume per station, time and jet requirement
Coordinate supply with waste aspiration
Line prime
Path volume, trapped high points and allowed bubbles
Confirm complete fill after empty source
Cuvette or manifold rinse
Parallel branches and nozzle restrictions
Measure the lowest-flow branch
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
Required installed flow
wash volume ÷ available seconds × 60
Compare with pump curve at system pressure
Path volume
sum of tubing and component internal volumes
Sets minimum prime and exchange liquid
Drain margin
wash supply + aspirated air allowance
Prevents wash-station overflow
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
Check source level→Prime to waste→Open wash branch→Deliver timed wash→Aspirate residual→Verify no overflow or air lock
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
Flow strong at pump, weak at probe
Restriction or manifold imbalance
Measure pressure and branch flow
Prime does not complete
Air trap, suction leak or excessive lift
Re-route high points and test inlet integrity
Station overflows
Waste capacity below supply
Increase aspiration or interlock supply
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
Delivered wash
Per outlet at installed path
Volume/time and branch balance
Cleaning result
Blank or carryover after worst contamination
Meets method criterion
Recovery
Empty bottle replacement and long idle
Prime completes within allowed cycles
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.
