How to Specify Tubing for IVD and Laboratory Instruments
How to Specify Tubing for IVD and Laboratory Instruments
Tubing for IVD and laboratory instruments must be specified around its actual function: fluid transport, electrical insulation, structural guidance or localized protection. PI, PEEK and fluoropolymer tubing have different strengths, but cleanliness, dimensions, media compatibility, carryover risk and documentation can be more important than the polymer name. Use this guide to build a supplier-ready specification without assuming medical or diagnostic approval.Contents
First define what the tube does
A fluid-path tube needs media compatibility, low carryover and controlled internal geometry. An insulating sleeve needs fit, electrical separation and thermal/process compatibility. A guide or protective tube needs dimensional stability, friction and mechanical behavior. Do not transfer a claim from one function to another, and do not assume a laboratory-use component is suitable for an IVD fluid path.
PI, PEEK or fluoropolymer tubing: screening table
| Candidate | Possible design direction | Questions before selection |
|---|---|---|
| Polyimide tubing | Thin-wall insulation or compact structural protection | Is it in the fluid path? What are the solvent, cleaning and particle requirements? |
| PEEK tubing | Small-bore structural or fluidic components where grade properties fit | What pressure, connection, media and dimensional requirements apply? |
| Fluoropolymer tubing | Fluid or protective applications where the exact grade’s chemical behavior is useful | What surface, permeation, extractables, joining and flexibility constraints apply? |
This is a screening comparison, not a claim that WELLELE offers every material, grade or regulated-use configuration. Confirm product availability and the exact construction in the RFQ.
Engineering decision table
| Requirement | Why it matters | How to communicate it |
|---|---|---|
| Fluid/media list | Controls compatibility, carryover and cleaning | Name chemicals, concentration, time and temperature |
| ID and wall/OD | Affects flow, pressure behavior and fit | Drawing with measurement method and tolerances |
| Cleanliness | Residue and particles can affect sensitive analysis | Define limits and test method [CONFIRM] |
| Connection method | Fittings, bonding or thermal joining stress the tube differently | Production hardware and assembly parameters |
| Pressure/vacuum | Requires application-specific mechanical validation | Working, peak, temperature and test method |
| Regulatory/document scope | IVD responsibilities depend on intended use and market | List exact evidence required; do not use “medical grade” alone |
Common IVD and laboratory tubing risks
- Material compatibility is inferred from a generic chart rather than tested with the full reagent and cleaning cycle.
- Nominal ID is accepted without checking flow-critical tolerance and measurement agreement.
- Particles, residue or packaging contamination are discussed without numeric acceptance criteria.
- Pressure capability is quoted without temperature, fitting and test details.
- A supplier document is mistaken for validation of the finished analyzer or IVD device.
- Material or process changes occur without reviewing carryover, calibration or assembly impact.
Qualification sequence and RFQ data
- Classify the tube’s function and whether it contacts sample, reagent or waste.
- Define dimensions, media, pressure/vacuum, temperature, cleaning and service life.
- Select the exact material grade and tube construction.
- Inspect samples and build them with production connections.
- Test leakage, flow, carryover, cleaning, environmental and mechanical performance as applicable.
- Complete the instrument manufacturer’s risk management and regulatory validation.
Send WELLELE a drawing, material target, ID, OD or wall, length, tolerances, quantity, media list, temperature, pressure/vacuum, fittings, cleanliness/packaging criteria and requested documents. Use [CONFIRM] for availability, compliance, biocompatibility or validation evidence not already documented.
Frequently asked questions
Does “laboratory tubing” mean it is suitable for IVD use?
No. Intended use, fluid contact, risk, cleaning and market requirements determine the evidence needed. The instrument manufacturer must validate the finished product.
Which is better for a fluid path: PEEK or fluoropolymer?
It depends on media, pressure, stiffness, surface, joining and analytical requirements. Compare exact grades in the complete fluidic circuit.
How should cleanliness be specified?
Name the contaminant type, limit, sampling, extraction or test method, handling and packaging. “Clean” alone is not auditable.
Can PI tubing be used near a sensor or electrode?
It may be a candidate for insulation or protection, but assess chemistry, temperature, particles and electrical interfaces in that location.
Discuss an instrument tubing requirement
Send WELLELE your function diagram, drawing and media/process conditions for a capability review, sample discussion or quotation. Confirm all regulated-use and documentation requirements before purchase.
