Assogomma recommendations for the selection, storage, use and maintenance of rubber hoses

The Recommendations are drawn up in accordance with the following International Standards:

1. Selection criteria

To choose the right hose, you need to know the following parameters:

• 1.1. Suction pressure
  The maximum working pressure or suction value must be set. Note that if the pressure spikes or if the maximum allowable pressure is exceeded, the service life of the hose will be shortened.
• 1.2. Compatibility of transported substances
  The type, purpose, concentration, temperature and structure of the substance (liquid, solid or gaseous) must be established.
  When transporting a solid substance, it is necessary to determine the fraction size, density, quantity to be transferred, type and flow rate.
• 1.3. Environment
  It is necessary to know the place of use, the surrounding temperature, humidity and the possibility of the hose being exposed to weather. Special environmental conditions such as ultraviolet rays, ozone, seawater, chemical and other aggressive substances can cause premature wear of the hose.
• 1.4. Mechanical stress
  The following parameters must be set: tensile, torsional, bending stress; vibration, compaction, bending and longitudinal or transverse load. The minimum bending radius must also be set.
• 1.5. Pavement wear
  Although hoses are assumed to have good abrasion resistance, it is recommended to use protection in case of damage due to pressure surges, corrosion and/or chafing.
• 1.6. Operating position
  Indicate the intended location of the hoses: on the ground, suspended, or immersed in liquid.
• 1.7. Used or foreseen couplings
  We choose according to the following parameters:
  • couplings and flanges: type, size, thread type, standard mating thread and application;
  • assembly: inner and outer diameter and coupling length;
  • staples: type and dimensions.
  Full hose to coupling compatibility will ensure high performance. The assembly performs well at recommended operating pressures.
• 1.8. Technical Standards
  National, European and International technical standards and regulations must be adhered to.
  In case of a special purpose other than the standard one, it is recommended to develop an individual technical description together with the manufacturer.
• 1.9. Labeling
  The manufacturer is obliged to mark the entire length of the hose with the necessary information on use.
  If the information is unclear or insufficient, the manufacturer should be contacted.

2. Recommendations for proper storage

Rubber is a material that changes its physical properties over time. Depending on the type of rubber, these changes can be caused by a number of factors that accelerate wear.
Unfavorable storage conditions also have a bad effect on the sealing material.
To minimize the possibility of wear and tear on stored items, follow the precautions described in these guidelines.

• 2.1. Shelf life
  Storage time should be minimized based on warehouse turnover.
  If long storage cannot be avoided, the purchaser should perform a complete inspection of the hose before use. According to ISO 8331, the storage period is as follows:
  • maximum 2 years for kits;
  • four years tops for hoses.
• 2.2. Temperature and humidity
  The best storage temperature for rubber hoses ranges from 10 to 25 °C. It is not recommended to store products at temperatures above 40 °C or below 0 °C.
  If the temperature is below -15˚C, precautions should be taken.
  Do not store hoses near heat sources or in high humidity. The humidity level should not exceed 65%.
• 2.3. Lighting
  It is recommended to store hoses in a dark room, out of direct sunlight or bright light. If there are windows or glass openings in the room, they should be covered with a screen (shade, curtain).
• 2.4. Oxygen and ozone
  Hoses should be packed in airtight containers to prevent air infiltration. Since ozone is corrosive to rubber, there should be no ozone-producing products in the storage area (e.g. high voltage objects, electric motors and other devices that cause sparks or electric arcs).
• 2.5. Interaction with other materials
  Do not allow the following substances to come into contact with the hose: solvent, various fuels, oil, grease, volatile chemical mixtures, acids, disinfectants and other organic substances.
  In addition, direct contact with certain metals (e.g. manganese, iron, copper and their alloys) has a detrimental effect on some types of rubber.
  Contact with timber and fabric impregnated with polychloridvinyl and creosote must be avoided.
• 2.6. Heat source
  The temperature control must be fully complied with in accordance with point 2.2. If this is not possible, use thermal protection at a distance of at least 1 meter.
• 2.7. Electric and magnetic field
  Fluctuating magnetic and electric fields must be avoided as this can cause heating of the metal couplings. High magnetic or electric fields can also be caused by high voltage wires or high frequency generators.
• 2.8. Storage conditions
  Hoses should be stored free from stress, compression and other deformations.
  Contact with objects that could cut or puncture the hose must also be avoided.
  It is preferable to store hoses on special shelves or on a dry surface. It is recommended to store the hoses horizontally, without stacking them on top of each other. If this is not possible, when stacking hoses on top of each other, make sure that the hoses underneath are not deformed.
  The inner diameter of the winding must remain as specified by the manufacturer, not less.
  It is not recommended to store the product on logs or on steep bends. It is preferable to supply hoses in a straight horizontal position, without wrapping.
• 2.9. Rodents and insects
  If there is a risk of insects or rodents entering the sleeves, all necessary measures should be taken to protect the products.
• 2.10. Product labeling or packaging
  The packaging should be labeled so that the hoses can be easily identified without taking them out of the box.
• 2.11.Warehouse removal
  Before shipping the hoses, it is necessary to check their technical condition, which must comply with the requirements.
  If the products have been in storage for a long time, the couplings should be checked. If they are not compressed, shackled or embedded, check that the locking ring is tight.
• 2.12. Return to stock
  Before taking used hoses into storage, they must be checked for cleanliness. Pay special attention to those hoses that have been used for the transfer of aggressive substances: chemical, explosive, flammable mixtures, hard and corrosive. After thorough cleaning it is necessary to check the technical condition of the hose.