Bellows Materials

The rubber blends adapted to our requirements are obtained from reputable manufacturers. We work with them continuously to further develop and optimize the blends. The physical and chemical properties are specified in detail in the materials datasheets and every batch of rubber delivered is subjected to extensive goods receipt inspections.

Rubber Grade Table

Explore Rubber Shore Hardness

If it is not possible to select a rubber grade that will endure for the long term due to the corrosiveness of the medium or the diversity of materials being conveyed, we can provide expansion joints with an interior fluoroplastic lining of PTFE / FEP.

Explore PTFE Lining

The reinforcements of the rubber bellows are high-quality synthetic fabrics which bear the forces from the internal pressure or vacuum. The type, quantity and arrangement of the reinforcements are designed in keeping with Pressure Equipment Directive PED 2014/68/EU. All carriers are impregnated with rubber, completely embedded in the bellows and are firmly connected to the body.

Wire or solid steel rings made from carbon or stainless steel embedded in the bellows construction are used as strengthening members of the expansion joint. A steel ring embedded in the top of the bend prevents the expansion joint body from collapsing under vacuum; it has no media contact and is not washed around by flow turbulence. Special packing and transport means must be considered for very large dimensions because the bellow with embedded steel ring cannot be squeezed anymore.