Pumps, valves, probes, fittings, tubing and sensing components for precise sample preparation, reagent handling and instrument fluidics.
Fluidic Valves for Detector Diversion, Bypass and Waste
Application guide · Diversion
A diversion valve sends liquid to detector, reaction path, collection or waste according to the analytical window. Its value is the state transition: the controller must know when the required composition has reached the valve and where any off-spec leading or trailing volume will go.
Engineering example: a 200 μL path between a mixing junction and diversion valve operated at 1 mL/min introduces about 12 seconds of nominal transport delay. Switching at the mixer command time would therefore send the wrong composition to the detector unless transit and dispersion are included.[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
Detector bypass
Stabilization time and valid read window
Keep prime and transition liquid away from the detector
Fraction or sample collection
Arrival window and collection volume
Coordinate valve state with actual transit
Waste isolation
Cleaning chemistry and safe destination
Prevent cleaner from reaching sensitive components
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
Nominal delay
upstream volume ÷ installed flow
Starting point for switch timing
Transition band
dispersion and mixing around concentration change
Defines waste allowance
Outlet balance
resistance of each destination path
Prevents flow change when state changes
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
Prime to waste→Establish stable composition→Wait for transit or sensor trigger→Switch to valid destination→Complete acquisition→Divert wash and return safe
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
Detector sees wash front
Switch too early or wrong state
Measure actual transit with tracer
Flow changes on diversion
Unequal branch resistance
Balance outlets or control flow independently
Collected fraction is diluted
Broad transition or excess common volume
Reduce volume and narrow collection window
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
Switch timing
Tracer transition at final destination
Valid window is captured
Branch flow
Measure both states at installed load
No unacceptable method disturbance
Safe state
Power loss and controller reset
Liquid reaches the defined safe destination
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.
