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:

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 90° which has an external radius of 70 mm, the minimum hose length with a bending radius of 450 mm comes to:

In this case the bend extends over a hose length of a minimum of 762 mm.