EN12115

What is EN 12115 all about ?

EN 12115 is the European standard for  Rubber and thermoplastics hoses and hose assemblies for liquid or gaseous chemicals

Dimensions
Standard imposes:

  • tolerances on ID / OD
  • tube and cover minimum thickness
  • Minimum bending radius
  • Resistance to vacuum (-0.8 bar minimum for SD type – with helix) and, something we tend to forget -0.5 (ID 13 and 19mm), -0.4 (ID 25 to 38mm) and -0.3bar (ID 50mm) for D
  • tolerances on hose assembly length ( 15/-10mm for length < 1m; +1.5%/-1% for length above 1m)

Physical properties of materials
Standard specifies expected values for tensile strength, elongation at break for both tube and cover compounds, as well as ageing and abrasion resistance for cover only.

Colour code for branding

Material of helix(es) should be galvanized hard or mild steel, or stainless steel if so required.

Performance requirements for hoses and hose assemblies:

  • proof test pressure at 1.5 x working pressure
  • Change in length under proof pressure (max. 8% for D type, 10% for SD, ) and vacuum (SD type only, -2%)
  • Twist at proof pressure (maximum 8°/m)
  • Resistance to vacuum for type SD : hose should stand vacuum for 10mn with no damage / change.
  • Vacuum stability for type D : no change in diameter and / or length above -2%
  • Burst pressure = 4 x working pressure
  • Adhesion between different layers > 2,4 N/mm
  • Crush recovery for SD type : hose will recover minimum 97% nominal OD latest 5min after a force (1500N up to 50mm; 2000N above) is applied onto it for 3 min.
  • Ozone resistance : test according to ISO 7326 under specific conditions.
  • Flammability test : test piece in U shape is exposed to Bunsen burner naked flame during 3min, no flame after 20s further to removal of burner, no further glowing after 2mn and no leakage.
  • Bending : OD should not deform of more than 10% at bending radius (for D type, test is done with 0.7 bar inside)
  • Flexibility at 20°C : test according to ISO4672, method B, there should be no permanent deformation or visible structural damage.

Electrical properties and branding:
Hose can have either
- 2 low resistance bonding wires crossing uniformly with each other: in that case, resistance should be < 10exp2 Ohm per length and hose marked with "M"
Or
- electrically conducting materials in its construction: in that case, resistance should be < 10exp6 Ohm per length and hose marked with "OMEGA’’

Where dissipation of electrostatic charges is a safety requirement (e.g. in explosive environments), hose assemblies should also have electrical resistance < 10exp9 through the hose and be marked with "/T"

Testing

Besides type (i.e. standard compliance) tests which should be made at least every 5 years, production acceptance tests are to be made regularly, some every 1000m and others every 10000m produced at the maximum.
There are also routine checks which apply to every hose or hose assembly.

Marking Hoses, fittings and hose assemblies !
There are a lot of information that should be written on hose, on fittings and also on hose assemblies.
For hose, please refer to our embossed texts.
For fittings, there should be manufacturer’s name or trademark, type and nominal size, material and max WP.
Hose assemblies should also have 2 identification bands with following information:

- band #1 which shall remain permanently on hose assembly

  • Operator / assembler registration number
  • Admissible operating pressure
  • Admissible operating temperature
  • Symbol to identify electrical conductivity (e.g. OMEGA/T)
  • Date of assembly

- band #2 which should be removed and replaced after each routine test

  • Test laboratory name / ID
  • Date of first fitted or test date
  • Date next test is due

Storage and admissible storage time
Reference is made to ISO 8331 which states that bulk hoses (non fitted) can be stored up to 4 years max. 2 years as assembly. However, EN 12115 hoses and hose assemblies which have been stored for 3 years from date of production or date of last test should undergo the complete routine testing.