Flame-retardant
PROTAPE® PVC 371 (HD)
Heavy, self-extinguishing PVC ventilation hose with spring steel wire embedded in the wall and fabric reinforcement. Tested self-extinguishing per ISO 3795. Service from −20 °C to +90 °C — wider temperature range than the MD and LD variants. Designed for galvanic extraction, chemical industries and general extraction units where a heavier cover is needed.
- Self-extinguishing ISO 3795
- −20 to +90 °C
- Heavy duty
- Fabric-reinforced
- Abrasion-resistant wall
- Cut to length
Why this hose?
PROTAPE® PVC 371 (HD) is the heavy duty variant in the PROTAPE® PVC 371 range. It's designed for more demanding industrial extraction tasks than the MD and LD variants — where the hose must handle both higher temperatures and more mechanical wear over time.
Self-extinguishing properties are tested per ISO 3795 — the standard used in the automotive industry to ensure materials don't continue burning after the flame is removed. It's a stricter way of assessing fire response than ordinary flame-retardant tests.
In practice the HD variant is preferred for galvanic extraction and chemical industries, where the processes generate both aggressive vapours and higher temperatures than ordinary ventilation. The blue colour is the manufacturer's standard marking for the HD variant — easy to distinguish from the grey MD/LD variants.
Where it is used
The hose typically sits on galvanic production lines as a connection between tank and extraction system. Galvanic processes release vapours that are corrosive and hot — the combination the HD variant is designed to handle over time.
In the chemical industry it's a standard choice on central extraction systems, especially where the medium is vapours from solvents or process chemicals. The 0.5 mm wall thickness makes the hose more abrasion-resistant than the MD variant in the same dimensions.
The hose can also be used as an industrial ventilation connection on machines with high wear — for example near cutting points on CNC machines or conveyor belts where dust or chips could abrade an ordinary PVC hose.
In everyday talk we call it a "heavy duty" or "HD" ventilation hose — the blue design is the first thing you recognise.
Technical specifications
Technical specifications for PROTAPE® PVC 371 (HD).
| Material | Heavy duty PVC, fabric-reinforced, spring steel wire |
|---|---|
| Colour | Blue |
| Inner diameter | 50–250 mm |
| Temperature | −20 to +90 °C |
| Self-extinguishing | ISO 3795 |
| Wall thickness | 0.5 mm |
| Conformity | ISO 3795, RoHS |
| Cut to length | Yes |
| Manufacturer SKU group | 3713401 |
Dimensions and ordering
Standard dimensions from Ø 50 mm to Ø 250 mm. The hose is heavier and stronger than the MD variant — see weight per running metre in the table.
| Inner Ø |
Outer Ø |
Wall thickness |
Working pressure |
Vacuum |
Bend radius |
Max. length |
Weight |
Article no. |
|---|---|---|---|---|---|---|---|---|
| 50 | 53.2 | 0.5 | 0.41 | 0.175 | 40.8 | 20 | 0.27 | 37100503401 |
| 60 | 62.2 | 0.5 | 0.34 | 0.13 | 48 | 20 | 0.32 | 37100603401 |
| 70 | 72.2 | 0.5 | 0.295 | 0.11 | 56 | 20 | 0.4 | 37100703401 |
| 75 | 78.2 | 0.5 | 0.275 | 0.095 | 60.8 | 20 | 0.55 | 37100753401 |
| 80 | 82.2 | 0.5 | 0.255 | 0.095 | 64 | 20 | 0.42 | 37100803401 |
| 90 | 92.2 | 0.5 | 0.23 | 0.085 | 72 | 20 | 0.47 | 37100903401 |
| 100 | 104.8 | 0.5 | 0.205 | 0.06 | 81.6 | 20 | 0.46 | 37101003401 |
| 110 | 112.4 | 0.5 | 0.185 | 0.055 | 88 | 20 | 0.71 | 37101103401 |
| 120 | 122.4 | 0.5 | 0.17 | 0.05 | 96 | 20 | 0.54 | 37101203401 |
| 125 | 129.8 | 0.5 | 0.165 | 0.04 | 101.6 | 20 | 0.57 | 37101253401 |
| 140 | 142.4 | 0.5 | 0.14 | 0.04 | 112 | 20 | 0.63 | 37101403401 |
| 150 | 154.4 | 0.5 | 0.135 | 0.04 | 121.6 | 20 | 0.68 | 37101503401 |
| 160 | 164.8 | 0.5 | 0.13 | 0.025 | 128 | 20 | 0.72 | 37101603401 |
| 180 | 182.6 | 0.5 | 0.115 | 0.025 | 144 | 20 | 0.81 | 37101803401 |
| 200 | 205.6 | 0.5 | 0.105 | 0.025 | 162.4 | 20 | 0.91 | 37102003401 |
| 250 | 252.6 | 0.5 | 0.085 | 0.02 | 200 | 20 | 1.13 | 37102503401 |
| 254 | 256.6 | 0.5 | 0.085 | 0.02 | 203.2 | 20 | 2.02 | 37102543401 |
| 300 | 302.6 | 0.5 | 0.07 | 0.01 | 240 | 20 | 1.36 | 37103003401 |
| 305 | 307.6 | 0.5 | 0.07 | 0.01 | 244 | 12 | 1.38 | 37103053401 |
| 350 | 352.8 | 0.5 | 0.04 | 0.01 | 280 | 12 | 1.46 | 37103503401 |
| 356 | 358.8 | 0.5 | 0.04 | 0.01 | 284.8 | 12 | 1.48 | 37103563401 |
| 400 | 402.8 | 0.5 | 0.035 | 0.005 | 320 | 12 | 1.67 | 37104003401 |
| 406 | 408.8 | 0.5 | 0.035 | 0.005 | 324.8 | 12 | 1.69 | 37104063401 |
| 500 | 503 | 0.5 | 0.3 | 0.005 | 400 | 12 | 2.22 | 37105003401 |
| 508 | 511 | 0.5 | 0.03 | 0.005 | 406.4 | 12 | 3.12 | 37105083401 |
| 600 | 603 | 0.5 | 0.02 | 0.005 | 480 | 10 | 4.95 | 37106003401 |
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
PROTAPE® PVC 371 (HD) is tested and compliant with the following:
- ISO 3795. Standard test for self-extinguishing properties, used in the automotive industry. Materials that pass the test will stop burning within a defined time after the flame is removed.
- RoHS. Directive 2011/65/EU on the restriction of hazardous substances.
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
PROTAPE® PVC 371 (HD) is used where a heavier ventilation hose is needed:
In galvanic industries the hose combines flame retardance, corrosion resistance to galvanic vapours and a heavy-duty cover that doesn't degrade under continuous service over months or years. The blue colour marks it as the HD variant — important during maintenance and replacement.
In general chemical process industries it's used as a connection on central extraction systems where process chemicals release vapours. The ISO 3795 properties give extra confidence in environments where fire risk must be minimised.
In HVAC installations in industrial buildings it functions as a long-term stable ventilation trunk — especially where temperature can swing widely between −20 and +90 °C in seasonal installations.
Custom lengths and assemblies
The hose is delivered on rolls in 10 m and 20 m lengths. We cut to length and fit couplings or sleeves as a finished assembly.
For serial deliveries we can establish repeatable assembly for consistent quality across the entire delivery.
Frequently asked questions
What's the difference between PROTAPE® PVC 371 (HD) and (MD)?
The HD variant has thicker wall (0.5 mm vs MD's thinner wall), wider temperature range (−20 to +90 °C vs MD's −10 to +80 °C) and is tested self-extinguishing per ISO 3795. The blue colour marks HD; MD is grey. Choose HD when the hose must handle more mechanical wear or higher temperatures.
What does ISO 3795 mean?
ISO 3795 is an automotive standard for self-extinguishing materials. A material passes when it stops burning within a defined time after the ignition source is removed. It's stricter than some other flame-retardant tests because it measures active self-extinguishing, not just resistance to ignition.
Is it ATEX-approved?
No. The PVC wall is insulating and the hose is neither conductive nor antistatic. For ATEX zones choose a conductive or antistatic hose — for example PROTAPE® PUR 332 SE (LD) (antistatic + flame-retardant).
Does it tolerate galvanic vapours?
Yes. PVC has good chemical resistance to most galvanic vapours at operating temperatures up to +90 °C. For specific process chemicals — especially strong concentrated acids — you should cross-check in the resistance table, or contact us for assessment.
How big is the bend radius?
Bend radius is shown in the dimension table for each inner diameter. The hose is heavy duty and the bend radius is slightly larger than the MD variant in the same dimensions. For Ø 50 mm: 40.8 mm. For Ø 250 mm: scales proportionally.
Can I get it with couplings?
Yes. We cut the hose to your measurements and fit hose bands, clamping bands, threaded couplings or bayonet as a finished assembly. Tell us which coupling system you have, and we'll suggest the right match.