Food/Pharma · Food-grade
NORFLEX® SIL 408
Highly flexible and crush-resistant food-grade silicone hose, heat-resistant up to +180 °C and cold-resistant down to −60 °C. Suitable for applications in the food and pharmaceutical industry — particularly hose pumps, tablet presses, dosing hoses and buffer connections where a chemically neutral, transparent hose is required. Inner diameter 2–25 mm across 14 dimensions.
- Food-grade
- −60 to +180 °C
- Transparent
- Highly flexible
- Smooth interior
- Cut to length
Why this hose?
NORFLEX® SIL 408 is a pure silicone hose with no spiral or fabric reinforcement. It's platinum-cured — that process gives cleaner material properties than the older peroxide curing, and is typically used where the product needs to be compatible with pharmaceutical or medical equipment.
The broad temperature range (−60 to +180 °C) makes it useable both in freezing applications and in CIP/SIP cleaning processes where hot water or steam passes through. Smooth interior reduces particle or bacterial deposition — important in hygiene-critical applications.
In peristaltic (hose) pumps, it's exactly the flexibility and crush resistance that makes the hose suitable — it's compressed repeatedly without losing shape. In tablet presses it serves as a dosing hose for filling materials that must be visually followed through the transparent wall.
Where it is used
The hose typically sits inside peristaltic (hose) pumps, where it's the only part of the pump that contacts the medium. That's clever because the pump has no shaft seals or valves to maintain — and because hose replacement is the only service the pump needs.
In pharmaceutical production it's used to transport buffers, ingredients and dosing. The platinum-cured silicone is compatible with most pharmaceutical media at room temperature, and tolerates both SIP (Steam-In-Place) and autoclave sterilisation.
In the beverage industry it's used in smaller dimensions as dosing hoses for flavourings, concentrates or carbonation — applications where a transparent hose is an advantage because the flow can be visually verified.
In everyday talk we call it a pharma silicone hose — the go-to when the medium is chemically neutral and you need heat- and cold-resistance in the same product.
Technical specifications
Technical specifications for NORFLEX® SIL 408. The dimensions cover small dosing applications (Ø 2 mm) up to medium-sized transfer hoses (Ø 25 mm).
| Material | Platinum-cured silicone, food-grade |
|---|---|
| Colour | Transparent |
| Inner diameter | 2–25 mm |
| Temperature (continuous) | −60 to +180 °C |
| Temperature (peak) | +180 °C |
| Wall construction | Smooth interior + exterior, extruded |
| Food-grade | Yes |
| Conformity | REACH, RoHS |
| Cut to length | Yes |
| Manufacturer SKU group | 4080000 |
Dimensions and ordering
Standard dimensions for NORFLEX® SIL 408 from inner diameter 2 mm up to 25 mm. The hose is an extruded silicone without pressure reinforcement; vacuum and working pressure are not specified by the manufacturer because the application is typically flow-controlled by the pump, not by pressure.
| Inner Ø |
Outer Ø |
Wall thickness |
Max. length |
Weight |
Roll |
Article no. |
|---|---|---|---|---|---|---|
| 2 | 4 | 1 | 50 | 0.01 | 50 | 40890200000 |
| 3 | 5 | 1 | 50 | 0.01 | 50 | 40890300000 |
| 4 | 6 | 1 | 50 | 0.02 | 50 | 40890400000 |
| 5 | 7 | 1 | 50 | 0.02 | 50 | 40890500000 |
| 6 | 9 | 1.5 | 50 | 0.04 | 50 | 40890600000 |
| 7 | 10 | 1.5 | 50 | 0.05 | 50 | 40890700000 |
| 8 | 10 | 1 | 50 | 0.03 | 50 | 40890800000 |
| 9 | 13 | 2 | 50 | 0.08 | 50 | 40890900000 |
| 10 | 14 | 2 | 50 | 0.09 | 50 | 40891000000 |
| 12 | 16 | 2 | 50 | 0.1 | 50 | 40891200000 |
| 15 | 21 | 3 | 25 | 0.2 | 25 | 40891500000 |
| 16 | 22 | 3 | 25 | 0.21 | 25 | 40891600000 |
| 20 | 26 | 3 | 25 | 0.27 | 25 | 40892000000 |
| 25 | 31 | 3 | 25 | 0.31 | 20 | 40892500000 |
Fields without a value (—) are not specified in the manufacturer's factsheet. Overpressure and underpressure values are recommended operating limits; the product can be subjected to higher loads on request. Bend radius is measured along the inside of the hose bend.
Standards and compliance
NORFLEX® SIL 408 conforms to the following standards and directives:
- REACH (EC 1907/2006). The manufacturer's REACH declaration is available for download.
- RoHS. Directive 2011/65/EU on the restriction of hazardous substances in electrical and electronic equipment.
- EU 1935/2004. Materials in contact with food; the manufacturer has specific food-grade certification for this material.
- FDA 21 CFR 177.2600. US standard for rubber-based materials in contact with food.
Documentation and downloads
Additional documents about this hose, its compliance and installation. Click to download as PDF in a new tab.
Help with material selection
Although this hose isn't ATEX-relevant, these two articles provide useful background on electrical resistance and industrial safety — important if you later combine the hose with electrical equipment or work in mixed environments:
The invisible weakest link
Why a conductive or antistatic hose isn't sufficient on its own — and what grounding means for the complete system.
Know your ohm
The difference between antistatic and conductive, which resistance limits apply where, and how to measure them correctly.
Industries that use it
NORFLEX® SIL 408 has a place in industries where cleanliness, heat resistance and flexibility are core parameters:
In the food industry it's especially peristaltic pump applications where SIL 408 stands out as a standard. The hose is the only pump part that contacts the medium, so material cleanliness becomes decisive — and platinum-cured silicone is at the top of the class for material purity.
In pharma it's used for CIP/SIP-cleaned transfer lines for buffers and ingredients. The fact that the hose tolerates both +180 °C (steam) and −60 °C (frozen storage/transport) makes it a versatile choice across the same production line.
In medical technology it's used in clinical equipment and laboratory bench installations, where the transparent construction enables visual flow verification — a simple but important functionality in quality-critical environments.
Custom lengths and assemblies
The hose is delivered on rolls in 25 m and 50 m lengths. We cut to length and can fit clamps, couplings or fittings — whatever your pump or installation requires.
For serial deliveries we can set up repeatable assembly so you get consistent assemblies across the entire delivery. Ask us if you need special lengths or special assembly.
Frequently asked questions
Is NORFLEX® SIL 408 approved for contact with food?
Yes. The hose is made of platinum-cured silicone that meets EU 1935/2004 and FDA 21 CFR 177.2600 for materials in contact with food. The manufacturer's specific food-grade certification is available on request.
What's the difference between platinum-cured and peroxide-cured silicone?
Platinum curing is a modern process that leaves fewer volatile residues in the material than the older peroxide curing. This gives cleaner material properties, lower extraction during heat/sterilisation, and better compatibility with pharma and medical applications.
Does it tolerate autoclave sterilisation?
Yes. The hose tolerates standard autoclave cycles up to +134 °C without issue, and short-term steam up to +180 °C in SIP (Steam-In-Place). For repeated high-temperature cycles, lifetime should be assessed — the silicone gradually stiffens over time.
Can it be used for vacuum?
The hose is not reinforced, so it collapses under high vacuum or if compressed externally during flow. For vacuum applications choose a reinforced variant — for example NORFLEX® SIL 408 SPECIAL WALL with increased wall thickness or a spiral-reinforced silicone hose.
What's the difference between SIL 408 and SIL 408 SPECIAL WALL?
Standard SIL 408 has a standard wall thickness suitable for typical hose pumps and dosing. The SPECIAL WALL variants (2 mm, 3 mm, 15 mm, 25 mm) have increased wall thickness and are used where the hose must withstand higher mechanical load or vacuum, or where long lifetime in a hose pump is important.
How long is the lifetime in a peristaltic pump?
It depends greatly on pump make, working pressure, medium viscosity and temperature — but typically from 200 to 1000 service hours for SIL 408 at standard dosing. SPECIAL WALL variants can reach 2-3× longer. We recommend a small wear test in your own pump configuration before deciding a replacement interval.
Is it compatible with strong acids or bases?
Silicone has good general compatibility with diluted acids and bases, but is not compatible with concentrated acids (above ~20%) or strong base concentrations. For chemically aggressive media choose a CP PTFE or CP HYP hose. We have a chemical resistance table for lookup — contact us if you're unsure.
Can I order it in a specific length?
Yes. The hose is delivered on rolls (25 m or 50 m), and we cut to your measurements and fit fittings, clamps or couplings as a finished assembly. For volume deliveries we can set up serial production runs for consistent assembly.