Basically every hose consists of the following three elements, each of which fulfills an important function:

 

• TUBE

The tube is the inner element of the hose and serves as the contact element for the medium to be conveyed. The choice of the right caoutchouc mixture guarantees the best conveyance of chemicals, oil, abrasive and many other media.
 

• REINFORCEMENTS

The reinforcement allows the necessary cross-sectional stability of the hose to resist static and dynamic pressures. This high-strength layer can be made up of diverse textiles, nylon, steel wire or a combination of these materials. If the hose is to be highly flexible or resistant to a high level of suction an additional steel wire helix is embedded in the reinforcement.
 

• COVER

The cover is the outer and therefore visible part of the hose. It protects the hose against external influences such as weather, temperature and mechanical damage which may occur during use. It is essential to select the caoutchouc mixture that corresponds best to the conditions for use.

 

FLEXIBILITY AND BENDING RADIUS
Flexibility and minimum bending radius are important factors in the design and selection of hoses, especially if the hose is to be subject to extreme bending during use.
It must be kept in mind that the expected bending radius in activity is higher than the minimum bending radius of the respective hose. If the radius is less than the minimum bending radius, the hose can kink, contract in the cross-section and even become flat. Thereby the reinforcements can come under excessive strain and may be distorted. This can reduce and even cut short the service life of the hose.
In general the minimum bending radius for every hose is indicated in this catalogue. The hose can be used without difficulties or shortening of its service-life up to the indicated radius. The radius is measured to the inner part of the bend.

The formula used to determine the minimum hose length given the bending radius and the desired degree of bending:
 

?/360° * 2? * (r + ô / 2) = L
Key: a = bending angle, r = given bending radius of the hose,
f = outer radius of the hose,
L = minimum length of the hose.

Example: For bending a hose by 90В° which has an external radius of 70 mm, the minimum hose length with a bending radius of 450 mm comes to:
90/360 * 2? * (450 + 70 / 2) = 762 mm
In this case the bend extends over a hose length of a minimum of 762 mm.