Mèrlett Tecnoplastic

indice:

• Choosing a hose
• General information
• Storage
• Norms and method of use
• Maintenance
• Disposal

1 CHOOSING A HOSE

To obtain an optimum yield, a hose as well as an accessory, must be chosen depending on the conditions of service in which it will be used and before deciding on the diameter, type and quality of the hose information on the real conditions of service must be looked into carefully. In choosing the hose and/or accessories to be used, the following must always be considered:
a) a perfect knowledge of the nature of the material to be conveyed
b) verification of compatibility with any connections
c) determining the size, length and tolerance limits suitable for use and assembly. Be aware of increased dangerous conditions when using a product especially in presence of children and elderly people.

2 GENERAL INFORMATION

The physical properties of plastic materials are subject by nature to changes both during the storage and while being used. These changes, which occur normally over time depending on the type of material that is used, can be accelerated by a particular factor or by a combination of factor. The reinforcement materials can be damaged by an inadequate use and/or by inadequate storage condition, therefore it is recommended that prolonged exposure to sunlight and atmospheric agents in general must be avoided. It is recommended to avoid storage near equipment which may promote development of ozone.

3 STORAGE

3.1 Recommendations for a correct storage

The following advice contains some precautions that need to be taken to ensure minimum deterioration of the stored goods.

3.2 Storage times

Storage times should be reduced to a minimum by means of a programmed rotation. When it is not possible to avoid a long time in storage and when the following recommendations are not observed the hose must be checked thoroughly before use.

3.3 Temperature and humidity

The optimum temperature for storage of plastic hoses is from 10 to 25 degrees centigrade. The hoses should not be stored in temperatures over 40°C or below 0°C. When the temperature is below -5°C precautions must be taken when moving the hoses. The hoses must not be stored near heat sources not must they be stored in the presence of high or low levels of humidity. The recommended level of humidity is a maximum of 65%.

3.4 Contact with other materials

The hoses must not come into contact with chemical products such as solvents, fuel, oil, grease, acids, disinfectants, etc., which may alter the physical-mechanical characteristics.

3.5 Heat sources

The temperature limit indicated in item 3.3 must be observed. When this is not possible, thermal protection must be used.

3.6 Storage conditions

The hoses must be stored in proper conditions, free from stress, compressions, or other deformations and contact with objects which may perforate or cut them must be avoided. The hoses should be stored on special shelves or on dry surfaces. The packaged hoses must be stored horizontally and not piled up. If this is not possible the height of the pile must be so that permanent deformation of the hoses on the bottom or near it is avoided. The internal diameter of the coil must never be less than double the bending radius declared by the manufacturer in accordance with the technical standards. It is recommended that the hoses are not stored on shafts or hooks. It is also recommended that the hoses, which are delivered straight, are stored horizontally without bending them.

3.7 Rodents and insects

The hoses must be protected from rodents and insects. If there is probable risk, adequate precautions must be taken.

3.8 Marking the packages

It is recommended that the hoses are always easily identifiable whether they are packaged or not. To allow traceability the label of a product is needed.

3.9 Collection from storage

Before delivery their must be controlled in their entirety.

3.10 Return to storage

The hoses which have been used must be cleaned, before storage, from all the conveyed substances. Particular attention must be paid when chemical, explosive, inflammable, abrasive and corrosive substances have been used. After cleaning, check that the hose can be re-used.

4 NORMS AND METHODS OF USE

After having chosen the type of hose, the user must take into consideration the following criteria for installation:

4.1 Opening the package

Pay attention when opening the packaging that the hose is not damaged due to the use of knives or cutters.

4.2 Pre-assembly checks

Before installation it is necessary the carefully check the characteristics of the hose to verify that the type, diameter and length conform to the requested specifications. A visual control must also be carried out to ensure that there are no obstructions, cuts, damaged cover or any other evident imperfection.

4.3 Movement

The hoses must be moved carefully, avoiding all blows, dragging on abrasive surfaces and compressions. The hoses must not be violently pulled when they are warped or kinked. Heavy hoses, normally delivered in a straight horizontal position, must be placed on special supports for transportation. If wooden supports, or supports of any other material, are used they must not be treated or painted with substances that could damage the hoses.

4.4 Pressure and tightness test

The working pressure which is generally indicated on the hose must be respected. After installation, when the air bubbles have been eliminated, gradually increase the pressure up to the working pressure to test assembly and check for any leaks. This test must be carried out in safe conditions.

4.5 Temperature

The hoses must be used within the temperature limits which are generally indicated. If, in doubt, contact the manufacturer. The working pressure indicated in the catalogue refers to a temperature of 23°C ± 2°C; different temperatures can lead to a different performance of the hose.

4.6 Transported products

The hoses must be used for the passage of substances for which they have been manufactured. If in any doubt it is always wise to contact the manufacturer. As far as is possible, the hoses must not remain under mechanical stress or pressure when not in use. If substances which are dangerous to health and/or the environment are transported, take any necessary measures to work in safe conditions if the hose should burst or be crushed.

4.7 Environmental conditions

The hoses must be used exclusively in the environmental conditions for which they have been manufactured.

4.8 Bending radius

Installation beneath the minimum bending radius considerably reduces the life and resistance of the hose and can cause damage. It is also necessary to avoid bending near the connections.

4.9 Torsion

The hoses are not made for working under torsion unless specifically designed for this purpose.

4.10 Vibrations

Vibrations can cause the hoses to undergo stress and possible overheating especially around the connections where, more frequently, premature bursts can occur. Therefore, it is best to verify that the hoses are made to resist this type of stress.

4.11 Kinks

Kinks are to be avoided as the reinforcement and the plastic materials are subjected to excessive stress which could cause a burst or reduce the hose performance. Some users tend to obstruct the passage of fluids by kinking the hose. This is to be avoided because of the a.m. reasons.

4.12 Choosing and assembling the fittings

As long as the manufacturer’s instructions are carried out, compatibility between the working pressure of the connections and the hoses must always be checked. Fittings with a bigger diameter than the hose can cause abnormal stress that can break the hose reinforcement, or damage the inner layer, whilst the use of fittings with a smaller diameter can result in difficulties when tightening the hose, cause leakages, or in case of multilayer hoses, cause infiltrations between the layers. Moreover the connections must not have sharp or cutting protuberances which could damage the hose. Water or soap and water can be used to insert the connections. Do not use products which contain oils or other aggressive products, unless they are the types of hoses destined to be used with these. It is forbidden to force the hoses with wood hammers or similar tools. Avoid external collars or other tightening tools. The use of improvised collars (for example metal wire) with sharp ends or fixing ties which are too tight cause damage to the cover and the reinforcement.

4.13 Dissipation of static electricity

When electric continuity is required, the manufacturer’s instructions must be observed; tests must be carried out to verify continuity between the connection and assembly. Check continuity with a normal tester.

4.14 Permanent installation

The hose must be adequately supported so that the pressurised hose can be moved normally (variations in length, diameter, torsion, etc.).

4.15 Moving installation

When the hose connects moving plants, it is necessary to check that the hose is long enough, that the movement does not cause the hose to undergo excessive strain and rubbing and that there is no stress, bending, traction or abnormal torsion.

4.16 Identification

If further marking is needed, self-adhesive tapes can be used. When the use of paint is necessary, consult the manufacturer to verify compatibility with the hose cover.

5 MAINTENANCE

5.1 Maintenance

Even if the choice, storage and installation have been carried out correctly, regular maintenance is also necessary. The frequency of the last is determined by the use of the hose. In normal controls particular attention must be paid to what regards connections and the presence of irregularities which indicate deterioration of the hose. Here below a non-exhaustive list of the possible irregularities:
- slits, cracks, cuts, abrasions, ungluing, tears of the cover (or of the inner part) which let the reinforcement show through.
- Deformations, bubbles, local swelling under pressure.
- Too soft or too hard parts.
- Leaks.
These irregularities justify replacement of the hose. When the cover shows an expiry date this must be observed even if the hose does not show any clear use signs.

5.2 Repairs

Repairs are not recommended. If, however, deterioration is at one end of the hose, this end can be cut off.

5.3 Cleaning

If the cleaning instructions are not supplied by the manufacturer, clean, if necessary, with soap and water and do not use solvents (petroleum, paraffin, etc.) or detergents. Never use abrasive, pointed or cutting tools for cleaning (metal brushes, sandpaper, etc.).

6 DISPOSAL

For a product’s disposal the laws in force are to be respected. Do not pollute the environment.