A peristaltic pump moves fluid by squeezing a flexible tube with rotating rollers. The tube is the only wetted part, which removes the need to clean the pump chamber between batches. This design is why peristaltic pumps dominate dosing in bioprocessing, laboratory analysis, dialysis, infusion and food dispensing. It is also why the tube, not the pump, determines flow accuracy, contamination risk and maintenance interval.
This article covers how to specify silicone tubing for peristaltic service: hardness, wall thickness, bore size, expected tube life, and the compliance documentation that medical, pharmaceutical and food buyers need.
Why Silicone Is the Common Choice for Peristaltic Tubing
Four tubing materials appear in peristaltic service: silicone, platinum-cured silicone, thermoplastic elastomer and PVC. Silicone is the default for several reasons.
Chemical resistance across a wide range of aqueous and mildly aggressive fluids
Temperature range from roughly -50 °C to 200 °C, allowing steam and hot liquid dosing
Compression recovery, so the tube returns to shape after each roller pass
No plasticizer, which avoids leaching into the pumped fluid
Transparent grades that allow visual inspection of flow and bubbles
Platinum cure options with a low extractable profile for sensitive fluids
The compression recovery property is central to peristaltic performance. Each roller pass flattens the tube, and the tube must spring back to refill before the next roller arrives. Silicone recovery is strong, which supports stable flow and long tube life when the wall thickness and hardness are matched to the pump head.
For the base material behind these tubes, see solid silicone rubber, the HTV family used for extrusion.
Hardness, Wall Thickness and the Flow Relationship
Three tube dimensions drive performance more than any other variable.
Bore or inner diameter (ID). Sets the volume per roller pass and therefore the flow rate at a given pump speed. Flow scales with the cross sectional area, so a small bore change produces a large flow change.
Wall thickness. Sets the squeeze ratio and the restoring force. Thin walls refill faster and suit high speed dosing. Thick walls resist higher discharge pressure and last longer under a given occlusion, at the cost of higher drive torque and slower refill.
Hardness. Sets stiffness and recovery. A harder tube resists creep and holds flow accuracy longer. A softer tube seals against the roller with less force and suits lower pressure and more delicate fluids.
Typical silicone peristaltic tubing runs from 50 to 70 Shore A. The common medical and lab range sits near 50 to 60 Shore A. Softer grades are available for low pressure dosing but tend to creep faster under continuous occlusion.
| Tubing Parameter | Typical Range | Effect on Performance |
|---|---|---|
| Bore (ID) | 1 to 12 mm | Direct driver of flow per roller pass |
| Wall thickness | 1.6 to 4.8 mm | Controls pressure capability and refill speed |
| Hardness | 50 to 70 Shore A | Sets sealing force, creep resistance and life |
| Operating temperature | -50 to 200 °C | Allows steam and hot fluid service |
| Sterilization tolerance | Autoclave, gamma, EtO | Method drives grade selection |
The tube life figure that vendors quote should always be tied to a specific pump head, speed, occlusion and back pressure. A life of 500 hours at low speed and low pressure is not the same duty as 500 hours at high speed against back pressure.
Tube Life and What Shortens It
Silicone peristaltic tubing in lab service commonly runs from several hundred to over a thousand hours, and the spread is large because duty varies so much.
The main factors that shorten life:
Occlusion setting. Over occlusion flattens the wall past full recovery and accelerates fatigue. Under occlusion reduces flow but extends life.
Pump speed. Higher speed means more roller passes per hour and faster fatigue accumulation.
Back pressure. Higher discharge pressure raises wall stress at each pass.
Temperature. Continuous hot service softens the tube and speeds creep.
Chemical exposure. Aggressive solvents and concentrated acids attack the surface.
Wall thickness. Thin walls fatigue faster than thick walls at equal occlusion.
The stress mechanism is mechanical fatigue, not chemical. In a medical tubing application such as LSR tubing for precision dosing, the same fatigue logic applies: recovery after compression is the property that governs service life.
A practical maintenance approach: log pump hours against a defined occlusion and speed, then replace the tube at 70 to 80 percent of the validated life rather than at visible failure. Flow drift near end of life is gradual and can escape a visual check.
Compliance for Medical, Pharma and Food Contact
Peristaltic tubing often touches biological fluids, drugs or food. The compliance set depends on the contact category and the market.
For medical and pharmaceutical contact, the common requirements are:
USP Class VI biological reactivity testing
ISO 10993 series biocompatibility, with ISO 10993-5 cytotoxicity and ISO 10993-23 irritation and sensitization
FDA 21 CFR 177.2600 for repeated use rubber articles where food or drug contact applies
A platinum-cure declaration, since peroxide residues can appear in extractables testing
For food and beverage dispensing:
FDA 21 CFR 177.2600
EU 10/2011 migration testing for the relevant simulant
REACH SVHC declaration
Note on standards interplay. ISO 10993 covers biological evaluation, USP Class VI covers a specific biological reactivity test set, and FDA 21 CFR 177.2600 covers rubber food contact. A single tubing grade can satisfy more than one, and the buyer should ask which reports are on file, with dates, rather than assume.
For sterilization, silicone tubing tolerates steam autoclave, gamma and EtO. Steam and gamma both run through the ISO framework already covered for medical silicone, and tubing grade selection interacts with the sterilization method the same way molded parts do.
Tube Grades: Platinum Cure Versus Peroxide Cure
Tubing is extruded and then cured. The cure system changes the extractable profile and the odor.
Platinum cure leaves no peroxide byproducts, holds a low extractable profile, and is the standard for USP Class VI and ISO 10993 tubing. It costs more and is more sensitive to cure inhibition from certain contaminants during extrusion.
Peroxide cure is cheaper and remains common in industrial and general purpose tubing. It can carry an odor and a higher extractable level, which is why it is avoided for drug, blood or infant food contact.
For most peristaltic medical and lab duty, specify platinum cure and request the extractable data.
Chemical Compatibility and Fluid Selection
Silicone handles a wide range of fluids, and it has known weak points that a buyer should check before specifying.
Silicone performs well with most aqueous solutions, alcohols, dilute acids and bases, and a wide range of biological fluids. This covers the majority of peristaltic dosing in pharma, dialysis, laboratory analysis and food service.
Silicone is attacked by concentrated acids, some ketones and aldehydes, aromatic and chlorinated solvents, and certain oils. In these fluids, silicone swells, softens and loses compression recovery quickly, which ends tube life and can release extractables into the fluid.
Where a solvent is involved, the options are a different elastomer such as a perfluoroelastomer or a thermoplastic tube, or a change in the fluid path. Selecting silicone for a solvent dosing task by default leads to early tube failure and possible fluid contamination.
A practical verification step: run a compatibility soak test on the actual fluid at the actual temperature for the planned contact time, then measure hardness, swell and compression recovery. A supplier compatibility chart is a starting filter, and the soak test is the confirmation.
Flow Accuracy and Pulsation
Peristaltic flow is inherently pulsatile because fluid moves only when a roller passes. Two parameters shape the flow profile.
Roller count sets pulse frequency. More rollers produce smaller, more frequent pulses and smoother flow. Fewer rollers produce larger pulses and a wider instantaneous flow variation.
Wall thickness and hardness set refill behavior. A tube that refills fully between passes delivers a consistent volume. A tube that refills slowly at high speed delivers less than nominal, which pulls the flow accuracy down.
For accuracy critical dosing, common requirements are a flow accuracy curve across tube life and a repeatability figure at the operating speed. Ask for both, measured at your wall thickness and speed rather than at a generic reference point.
Matching Tubing to the Pump Head
The pump head sets the occlusion geometry, and the tube must match it.
Confirm the pump head accepts the wall thickness you selected. Many heads are built around a fixed wall and will not hold flow accuracy with a different wall.
Confirm the tube length matches the head path. Excess length causes wander and uneven wear.
Confirm the drive torque. Thick, hard walls raise torque and can exceed a small drive's capability.
Confirm the roller count. More rollers mean smaller fluid pulses and more passes per revolution.
Flow accuracy is usually quoted as a percentage of nominal and depends on tube life stage, so ask for a flow accuracy curve across the tube life at your duty point.
Specification Checklist
State the fluid, including temperature, concentration and any solvent content
State the required flow rate and the pump speed range to be used
Specify bore, wall thickness and hardness as a matched set, not individually
Specify the cure system, platinum for sensitive contact
Require USP Class VI and the applicable ISO 10993 reports for medical contact
Require FDA 21 CFR 177.2600 or EU 10/2011 for food contact, with the simulant named
Require a tube life figure tied to a stated occlusion, speed and back pressure
Require a flow accuracy curve across life for accuracy critical dosing
Require a change control clause for compound and cure changes
Require lot traceability from tubing batch to compound lot
Where ANYSIL Fits
ANYSIL produces platinum-cure HTV silicone tubing and LSR grades from a Guangzhou facility with monthly capacity above 300 tons and 15 technical staff for grade development. Medical and food contact tubing grades are available across the 50 to 70 Shore A range, with documentation covering USP Class VI, ISO 10993 reports, FDA 21 CFR 177.2600, REACH SVHC and RoHS declarations prepared per order. Custom bore and wall combinations are available against a defined pump head.
Send the fluid, temperature, flow rate, pump head model and compliance requirement. The technical team will recommend a tubing grade and the data package needed for your validation file.
Request a peristaltic pump tubing assessment