Pumps, valves, probes, fittings, tubing and sensing components for precise sample preparation, reagent handling and instrument fluidics.
Tubing Material and Dimensions for Analytical Fluid Paths
Application guide · Tubing
Tubing diameter, length and material determine stored volume, pressure loss, response time and chemical exposure. Select each segment by its function—small-volume sample front end, reagent supply, wash line or waste path—rather than applying one tube size throughout the analyzer.
Engineering example: 1 m of 1.0 mm-ID tubing contains about 0.785 mL, while 1 m of 0.5 mm-ID tubing contains about 0.196 mL. The smaller bore cuts volume by four, but laminar pressure loss at the same flow rises approximately with the inverse fourth power of diameter before fittings 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
Sample front end
Low volume, sample integrity and carryover
Minimize length and unswept interfaces
Reagent/wash supply
Installed flow, compatibility and prime time
Balance pressure loss against stored volume
Waste/vacuum line
Air-liquid mixture, foam and drain capacity
Avoid collapse, traps and liquid carryover
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
Internal volume
π × ID² ÷ 4 × length
Sets prime, transition and residual liquid
Pressure loss
ID, length, flow, viscosity and fittings
Sets installed pump operating point
Residence time
path volume ÷ actual flow
Sets delay and chemical exposure
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
Define liquid and flow→Calculate volume and first pressure estimate→Add fittings/valves/filter losses→Route without traps or kinks→Prime and measure installed result→Inspect after aging and service
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
Slow prime
Excess volume or trapped high point
Shorten/re-route before only increasing speed
Dose delay varies
Tube compliance or bubbles
Control material, pressure and priming
Flow falls after service
Kink or wrong replacement ID
Use controlled part specification and inspection
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
Volume/response
Tracer arrival after switching
Matches cycle-time budget
Pressure loss
Minimum/routine/maximum flow and temperature
Within pump and component limits
Compatibility
Actual liquids, cleaners and idle exposure
No unacceptable swelling, leaching or cracking
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.
