Flame-retardant
AIRDUC PUR 352 SE RAILWAY PLUS (MD)
AIRDUC PUR 352 SE RAILWAY PLUS (MD) is a fire-safe suction and pressure hose specifically developed for railway and marine applications. The hose meets EN 45545-2 R23 HL1, R22 HL1/HL2 and R1 HL1/HL2/HL3 - i.e. all relevant hazard groups in passenger vehicles. The PUR construction is highly flexible, wear-resistant and lightweight.
- EN 45545-2
- -40 to +90 C
- Fire-safe
- Highly flexible PUR
- Suction and pressure
- Railway/marine
Why this hose?
AIRDUC PUR 352 SE RAILWAY PLUS is one of the very few hoses that meets EN 45545-2 on multiple hazard groups simultaneously - R23 HL1, R22 HL1/HL2 and R1 HL1/HL2/HL3. This means the same hose can be used in different installation positions in a passenger vehicle without switching to a different variant.
PUR (polyurethane) is chosen because it is one of the few elastomers that can both be formulated to be fire-resistant (with specific flame retardants) and retain mechanical properties under continuous operation. Standard PVC can be fire-modified but loses elasticity at high fire-resistance levels.
The low weight is important: in modern railway design every kg of extra weight is a fuel or battery capacity cost. PUR construction is typically 30-50 percent lighter than EPDM or PVC at the same dimensions - a significant advantage across a whole vehicle's installation.
Where it is used
Railway and tram industry uses the hose in ventilation, heating and sanitary installations. The typical position is as connecting hose between air conditioning and diffusers in the passenger compartment, or as roof drainage for rainwater. The fire approval is decisive because a passenger fire situation requires materials not contributing to ignition spread.
Shipbuilding uses the hose in all internal ventilation and sanitary installations on large passenger ships and naval vessels. The marine environment's moisture load combined with fire requirements makes the PUR construction a standard solution.
Industrial HVAC and special vehicles (defence equipment, ambulances, fire and rescue equipment) use the hose as a fire-approved component. Often there are no alternatives that meet the same fire approval on the relevant hazard groups.
AIRDUC PUR 352 SE RAILWAY PLUS is colloquially known as a railway hose or fire-approved PUR hose.
Technical specifications
The hose's key specifications are summarised briefly below. Pressure and vacuum values vary significantly per dimension - see the dimensions table for precise values.
| Outer wall/lining material | PUR (polyurethane) |
|---|---|
| Reinforcement | Textile plies |
| Fire approval | EN 45545-2 R23 HL1, R22 HL1/HL2, R1 HL1/HL2/HL3 |
| Colour | Black |
| Temperature range | -40 to +90 C |
| Working pressure | 1.06 to 2.53 bar (depending on dimension) |
| Vacuum | 0.155 to 0.485 bar (depending on dimension) |
| Bend radius | 34-80 mm depending on dimension |
| Standard roll length | 5 m (most) / 10 m (35 mm) |
| Manufacturer SKU | 3525400 |
Dimensions and ordering
The table shows the available standard dimensions. Pressure values fall gradually with increasing ID; vacuum resistance also varies per dimension - see the table for details.
| Inner Ø |
Outer Ø |
Wall thickness |
Working pressure |
Vacuum |
Bend radius |
Max. length |
Weight |
Roll |
Article no. |
|---|---|---|---|---|---|---|---|---|---|
| 20 | 27 | 0.9 | 2.53 | 0.485 | 34 | 5 | 0.34 | 5 | 35200205400 |
| 22 | 29 | 0.9 | 2.315 | 0.44 | 38 | 5 | 0.36 | 5 | 35200225400 |
| 25 | 32 | 0.9 | 2.055 | 0.385 | 44 | 5 | 0.39 | 5 | 35200255400 |
| 30 | 38 | 0.9 | 1.735 | 0.285 | 52 | 5 | 0.45 | 5 | 35200305400 |
| 32 | 40 | 0.9 | 1.63 | 0.265 | 56 | 5 | 0.47 | — | 35200325400 |
| 35 | 44.5 | 0.9 | 1.495 | 0.245 | 60 | 10 | 0.5 | — | 35200355400 |
| 38 | 46 | 0.9 | 1.385 | 0.225 | 64 | 5 | 0.53 | — | 35200385400 |
| 40 | 48 | 0.9 | 1.32 | 0.215 | 66 | 5 | 0.56 | 5 | 35200405400 |
| 42 | 50 | 0.9 | 1.25 | 0.02 | 68 | 5 | 0.58 | 5 | 35200425400 |
| 50 | 58 | 0.9 | 1.065 | 0.17 | 80 | 5 | 0.86 | 5 | 35200505400 |
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
The hose is manufactured to European standards for fire-safe hoses in passenger vehicles. EN 45545-2 is the primary fire approval.
- EN 45545-2:2013+A1:2015. European standard for fire resistance of materials in railway vehicles. The hose meets R23 HL1, R22 HL1/HL2 and R1 HL1/HL2/HL3.
- EN ISO 1307:2008. European standard for rubber and thermoplastic hoses for general use. Defines dimensions and pressure tolerance.
- EN ISO 8033:2016. Test of adhesion between lining, wall material and reinforcement. Critical for hose leak protection under cyclic operation.
- EN ISO 7233:2016. Determination of vacuum resistance.
- RoHS Directive (2011/65/EU). Restriction of hazardous substances. Manufacturer declaration on file.
- REACH (EC 1907/2006). Registration of chemical substances.
- ISO 9001:2015. Quality management system at the manufacturer.
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
AIRDUC PUR 352 SE RAILWAY PLUS is used in safety-critical installations where fire resistance per EN 45545-2 is required - primarily railway, tram and ship applications.
Railway and tram industry is the core market. Modern passenger vehicles require fire-approved components in all ventilation, heating and sanitary installations. EN 45545-2 is the European standard which AIRDUC PUR 352 SE RAILWAY PLUS meets at the largest number of hazard groups.
Shipbuilding and marine applications use the hose in ventilation, sanitary and extraction installations where fire resistance is required per SOLAS and MED directive. The PUR construction is also moisture-resistant - important in marine environments.
Other fire-relevant industries (public transport, paper industry with smoke extraction, industrial HVAC) use the hose as a standard solution where fire approval is necessary. The same dimension can typically be used across categories - a logistical advantage.
Custom lengths and assemblies
The hose can be delivered cut to desired lengths. The standard roll can be supplemented with shorter pieces or multiple rolls by arrangement.
At Particulair we advise on couplings and sizing. Send us a sketch of your application and we will assess the right variant and length.
Frequently asked questions
What is EN 45545-2 and why does it matter?
EN 45545-2 is the European standard for fire safety in railway vehicles. It classifies materials by hazard group (R-numbers) and hazard level (HL1-3). AIRDUC PUR 352 SE RAILWAY PLUS meets R23 HL1, R22 HL1/HL2 and R1 HL1/HL2/HL3 - i.e. the hose is approved for all relevant installation types in passenger vehicles.
What do the R-numbers mean?
The R-numbers specify where in the vehicle the material is used: R1 = general internal installation, R22 = electrical equipment internal wiring, R23 = ventilation and extraction systems. Each R-number has its own test protocol with hazard levels (HL) that specify how strict fire resistance is required.
Which dimensions does AIRDUC PUR 352 SE RAILWAY PLUS come in?
A wide range from ID 20 mm to ID 100+ mm. The pressure class falls gradually with increasing ID (2.53 bar at 20 mm down to approximately 1 bar at 50+ mm) - a consequence of the same wall thickness having to withstand greater force per cm circumference. Vacuum resistance also varies per dimension.
Is the hose electrically conductive?
No - the hose is insulating per the factsheet. For ATEX zones (zone 1, 2, 21, 22) or ESD-sensitive environments a conductive or antistatic variant is required. The AIRDUC series has ATEX-suitable variants (PUR 351 EC) - contact us for advice.
Can the hose handle thermal cycling?
Yes - the PUR lining is built for continuous operation between -40 and +90 C. Thermal cycling in passenger vehicles (summer/winter, operation/parking) is a typical load - PUR's elasticity is superior to PVC in this use. Brief peaks up to 90 C are allowed.
How long does the hose last in a railway installation?
Service life depends on installation position and thermal profile. Daily operation in passenger vehicles typically gives 8-15 years, matching rolling stock's overhaul cycle. The hose is constructed to ensure it does not need replacement before the next major overhaul - a large logistical advantage.
Why PUR instead of PVC or TPE?
PUR (polyurethane) is chosen because it combines three properties that are difficult to obtain in the same material: fire resistance per EN 45545-2, high wear resistance (critical in installations that are hard to maintain) and low weight which reduces the total vehicle weight - a major factor in modern railway design where every kg of extra weight costs fuel or battery capacity.
Are there smaller dimensions than 20 mm?
Standard AIRDUC PUR 352 SE RAILWAY PLUS starts at ID 20 mm. For smaller dimensions (10-19 mm) we recommend alternative AIRDUC PUR variants with the same fire approvals - contact us for the full portfolio. For specific installation lengths the hose can be delivered pre-assembled with couplings.