Food/Pharma · EU 1935/2004 + EU 10/2011
PROTAPE® PUR-C 335 FOOD-AS FLAT
Specialty hose for screening machines and vibrating equipment in food and pharmaceutical industries. Highly flexible, abrasion-resistant and vibration-resistant flat hose with a food-grade PUR wall and antistatic formulation. Food-grade per EU 10/2011, FDA 21 CFR 177.2600, GMP, and ATEX-approved for Zone 22 (dust, interior) plus Zone 1/2 (gases). Grounding wire integrated in the wall.
- Food-grade EU + FDA
- Antistatic + grounding wire
- Zone 1/2 + 22 interior
- Vibration-resistant
- Gas, dust, solid
- Cut to length
Why this hose?
PROTAPE® PUR-C 335 FOOD-AS FLAT is a specialty hose for screening machines and vibrating equipment in food and pharmaceutical production. Three construction details make it unique: flat form for vibrating equipment, food-grade PUR wall per all relevant standards, and integrated grounding wire that ensures consistent static-electricity dissipation on screening machines where mechanical vibration would otherwise generate significant static.
The hose is ATEX-approved for Zone 22 (dust, interior) and Zone 1/2 (gases). That covers the practical need in classified screening halls where flour, sugar, spices or pharmaceutical powders are handled.
Built for vibration. Standard suction hoses mounted on screening machines can develop wall cracks over time due to constant vibration. The flat construction and PUR formulation are specifically designed to resist this loading over long-term operation.
Where it is used
The hose is typically seen on screening machines and tumbler screens in food and pharma production, and as a flexible flat connection between silos and screening stations.
The formal product name is PROTAPE® PUR-C 335 FOOD-AS FLAT. In daily use: "the screening hose" or "food-flat".
Technical specifications
Specifications are current as of 15 April 2026 and refer to 20 °C.
| Material | Polyurethane (PUR-C), food-grade and antistatic |
|---|---|
| Colour | Transparent |
| Wall construction | Flat construction, 1 mm wall thickness |
| Spiral/conductor | 1 grounding wire integrated in the wall |
| Temperature range | −40 °C to +90 °C |
| Short-term peak | +125 °C |
| Electrical resistance | Antistatic wall <10⁹ Ω + integrated grounding wire |
| Food approval | EU 10/2011, EU 1935/2004, FDA 21 CFR 177.2600, GMP EU 2023/2006 |
| ATEX marking | Zone 22 (dust, interior) + Zone 1/2 (gases) |
| Cut to length | Yes |
| Manufacturer SKU (model group) | 3350000 |
Dimensions and ordering
The table shows the main variants from the manufacturer's factsheet. Fields without a value (—) are not specified. Diameters, pressure values and bend radii are normative; weights and roll lengths are typical production values.
| Inner Ø |
Outer Ø |
Wall thickness |
Working pressure |
Max. length |
Weight |
Roll |
Article no. |
|---|---|---|---|---|---|---|---|
| 50.5 | 53.05 | 1 | 0.58 | 2 | 0.36 | — | 33500500000 |
| 60 | 63 | 1 | 0.56 | 2 | 0.42 | — | 33500600000 |
| 80 | 83 | 1 | 0.51 | 5 | 0.56 | — | 33500800000 |
| 85 | 88 | 1 | 0.48 | 5 | 0.59 | 5 | 33500850000 |
| 90 | 93 | 1 | — | 5 | 0.63 | — | 33500900000 |
| 101.5 | 104.5 | 1 | 0.41 | 5 | 0.71 | 5 | 33501000000 |
| 110 | 113 | 1 | 0.375 | 5 | 0.76 | 5 | 33501100000 |
| 115 | 118 | 1 | 0.355 | 5 | 0.8 | — | 33501150000 |
| 120 | 123 | 1 | 0.34 | 5 | 0.83 | — | 33501200000 |
| 126.5 | 129.5 | 1 | 0.33 | 5 | 0.88 | 5 | 33501250000 |
| 151.5 | 154.5 | 1 | 0.275 | 5 | 1.05 | 5 | 33501500000 |
| 155 | 158 | 1 | 0.265 | 5 | 1.07 | 5 | 33501550000 |
| 160 | 163 | 1 | 0.255 | 5 | 1.11 | — | 33501600000 |
| 165 | 168 | 1 | 0.25 | 5 | 1.14 | 5 | 33501650000 |
| 180 | 183 | 1 | 0.23 | 5 | 1.25 | 5 | 33501800000 |
| 203 | 206 | 1 | 0.205 | 5 | 1.4 | 5 | 33502000000 |
| 205 | 208 | 1 | 0.2 | 5 | 1.42 | 0, 5 | 33502050000 |
| 220 | 223 | 1 | 0.185 | 5 | 1.52 | 5 | 33502200000 |
| 225 | 228 | 1 | — | 5 | 1.55 | — | 33502250000 |
| 250 | 253 | 1 | 0.165 | 5 | 1.73 | 5 | 33502500000 |
| 275 | 278 | 1 | 0.15 | 5 | 1.9 | 5 | 33502750000 |
| 305 | 308 | 1 | 0.135 | 5 | 2.1 | 5 | 33503050000 |
| 350 | 353 | 1 | 0.115 | 5 | 2.41 | 5 | 33503500000 |
| 356 | 359 | 1 | — | 5 | 2.45 | — | 33503560000 |
| 400 | 403 | 1 | — | 5 | 2.75 | — | 33504000000 |
| 405 | 408 | 1 | 0.105 | 5 | 2.79 | 5 | 33504050000 |
| 450 | 453 | 1 | — | 5 | 3.1 | — | 33504500000 |
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
The hose is certified to the following standards:
- ATEX 2014/34/EU + TRGS 727. Zone 22 (dust) and Zone 1/2 (gases).
- EU 10/2011 (relevant categories). EU regulation for plastics in food contact.
- EU 1935/2004. Framework regulation for food contact materials.
- FDA 21 CFR 177.2600. US food approval for polyurethane materials.
- GMP EU 2023/2006. Manufacturing process certified to Good Manufacturing Practice.
- REACH and RoHS. The manufacturer holds declarations of compliance.
- ISO 8031. Measurement of electrical resistance.
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
If you are choosing a hose and are uncertain about the right resistance level or zone classification, these two articles are a good place to start:
Industries that use it
The hose is used on screening machines and vibrating equipment in food and pharma industries:
Food and pharma industries use the hose for screening of flour, sugar, spices and pharma powders — wherever a screening machine combines with food contact and static-electricity risk.
Custom lengths and assemblies
The hose can be cut to length and assembled with couplings, cuffs and threaded fittings through Particulair's custom hose assemblies.
We offer guidance on material choice, coupling system and grounding, so the hose fits correctly into the overall system. If there is any doubt about zone classification or resistance requirements, a short conversation before ordering is well worth the time.
Frequently asked questions
What is a "flat" hose?
Flat construction means the hose is built to function lying flat — typically on screening machines and vibrating equipment where the hose needs to lay flat against a screening surface. That differs from standard round hoses that push a circular cross-section.
Why a grounding wire in the wall?
On screening and vibrating machines, significant static electricity is generated from the mechanical movements. An integrated grounding wire ensures the static electricity is consistently dissipated to ground — not only through the antistatic wall's surface resistance but also via a dedicated conductor.
Is the hose ATEX Zone 20-approved?
No. The hose is antistatic and covers Zone 22 (dust, interior) and Zone 1/2 (gases). For Zone 20 (the most restrictive dust class), a fully conductive hose is recommended, such as AIRDUC® PUR-INOX 351 FOOD-AS (MD).
Can the hose be supplied cut to length with couplings?
Yes. PROTAPE® PUR-C 335 FOOD-AS FLAT can be cut to length and assembled with couplings, cuffs and threaded fittings through Particulair's custom hose assemblies. We provide guidance on coupling system and sealing so the hose fits correctly into the overall installation.
How do I order the hose, and where do you deliver?
The hose is ordered through Particulair (Karlslunde, Denmark). We deliver to Denmark, the EU and selected third countries such as Norway and Switzerland. Standard dimensions can typically be delivered in 1-2 weeks; custom assemblies and larger volumes require slightly longer lead time.
What is the hose's expected service life?
Service life depends on operating conditions: loading, temperature, chemical exposure, UV and mechanical movement. In standard industrial use, expected life is 3-7 years. Aggressive conditions (high temperatures, continuous flexing, chemical vapours) reduce service life. We recommend regular visual inspection for cracks, deformation or discolouration.
How is the hose best stored before use?
Store the hose dry, at room temperature (15-25 °C) and out of direct sunlight. Avoid contact with ozone-generating equipment (welding equipment, engines). If stored on a reel, the bend must be larger than the specified minimum radius to avoid permanent deformation. Proper storage significantly extends shelf life.
What is the minimum bend radius, and what happens if I go below it?
Minimum bend radius is the smallest radius the hose can be bent to without permanent deformation or internal damage. The table above shows specific values for each dimension. Bending the hose below this limit can collapse the wall, kink the spiral or damage the inner coating. The result is reduced flow, increased pressure loss and shorter service life. Always use bend radius as a design constraint in installation.