Application Criteria

Corrosion

Rubber linings are a proven protection against corrosion of metallic materials in practice. Unfortunately, the combination of a diffusion-tight metallic carrier and a diffusion-permeable rubber lining carries unwanted failure risks, such as detachment with blistering and thus limited corrosion protection. The structural design of flexible rubber pipes eliminates this risk from the outset; the diffusion properties of the elastomers used are therefore irrelevant for the design. The homogeneous material bond after vulcanization ensures unrestricted operational safety throughout the entire service life. Partial detachment, as can occur with coated constructions, is thus excluded.

Abrasion

When used correctly, rubber proves to be extremely wear-resistant. Whether as a lining for sandblasting cabins, for hydraulic transport of abrasive solids in pipelines, or, for example, as car tires. The reason for this wear resistance is the elasticity of rubber, combined with high toughness. The material absorbs loads elastically and remains fatigue-free even over long periods. Rubber is therefore an ideal material to resist impact wear. Its resistance to dry sliding wear, on the other hand, is rather moderate. This means, in consequence, very high wear resistance for hydraulic conveying, while suitability for pneumatic conveying must be checked in each individual case.

Encrustation

Depending on the application and medium, deposits can form on the pipe wall that reduce the free cross-section and thus cause the pressure loss to rise excessively. If the deposits are hard and brittle, flexible rubber pipes offer a self-cleaning effect that prevents clogging. With unsteady pressures, the rubber pipe expands slightly in the radial direction. The closed, shell-like deposits crack open. Adhesion to the smooth, chemically neutral rubber surface is low, so the fine fragments are flushed away at sufficient flow velocity. Even with pneumatic dilute-phase conveying, clogging problems can occur. Particularly affected are substances with a very large particle surface, such as calcium hydroxide, color pigments, or soot. The micro-elasticity of rubber pipes absorbs the kinetic energy of the impacting particles elastically, preventing compaction and adhesion of the conveyed material. This prevents the so-called snowball effect.

Compensation

Changes in length as a function of temperature can be disregarded in the planning and operation of piping systems with rubber pipes. The very low modulus of elasticity results in forces so low that consideration in pipe statics is regularly unnecessary. At the same time, high elasticity ensures absorption of all length changes resulting from temperature fluctuations. Even in combination with piping systems made of rigid pipes, rubber pipes are excellently suited for compensation, so that permissible stresses are not exceeded. Especially when simple bellows compensators are ruled out due to insufficient wear resistance, rubber pipes offer the ideal solution.