Silicone Tubing Chemical Compatibility
Use compatibility tables for screening, then test the exact silicone formulation, fluid, concentration, temperature, and exposure time.
Silicone tubing is widely used because it is flexible and available in pump-compatible formulations, but the word silicone does not establish suitability for every chemical or analytical process. Formulation, cure system, hardness, additives, and manufacturing controls can differ.
Compatibility tables are screening tools. Final selection requires testing the exact tubing and exposure condition.
Define what compatibility means
A tube can remain visually intact while changing mass, dimensions, hardness, tensile behavior, permeability, or surface chemistry. The fluid may also extract compounds from the tubing or lose analytes through adsorption and permeation.
Define acceptable change for the application: no leakage, limited swelling, controlled flow drift, low extraction, retained clarity, or another measurable criterion. The right acceptance rule depends on whether the line performs transfer, dosing, sampling, or analysis.
Match the real exposure
Record every chemical, concentration, mixture, pH, temperature, pressure, exposure duration, cleaning agent, sterilization cycle, and idle condition. Mixtures can behave differently from individual components, and compatibility commonly decreases as temperature rises.
Dynamic peristaltic use adds repeated compression, so a static soak test alone is not enough. Compare new and exposed tubing for dimensions, mass, hardness or recovery, surface condition, pumping stability, and fluid-quality effects.
Use published data carefully
Check the supplier, formulation, test temperature, rating scale, and stated limitations behind a table. Do not transfer a rating from one silicone formulation to another without evidence.
Runze manual compatibility tables include conditions and limitations and should be treated as reference information rather than a guarantee. Verify the current manual, tubing specification, and application conditions before approval.
- Include cleaning and storage exposure in the test plan.
- Inspect the pumped liquid for contamination or composition change where relevant.
- Define a replacement interval after dynamic testing.
Engineering takeaways
- Compatibility includes mechanical performance and fluid quality.
- Test the exact formulation under dynamic operating conditions.
- Treat tables as screening evidence, not a universal warranty.