One of the first and most obvious applications of expansion joints is to use them to ensure the safety of pipelines on power plants. Though recently various types of joints have been applied in the chemical, pharmaceutical and food industries, as well as mining and cement industries.

The type of expansion joints - metallic, fabric or rubber - depends primarily on the pressure and temperature. They provide compensation for heat expansion, vibration and assembly inaccuracy and can compensate for axial, lateral and angular movements.

Our company is ready to offer customers the supply of all these types of joints produced by European leaders in this industry.

Model (type)
Nominal torque
No-load speed
Rated voltage

Metallic flexible elements by BHC Jilove s.r.o., Czech Republic


The metallic flexible elements built up from multiple layers. This technically well considered construction has many advantages. For example much smaller spring forces occur than with single walled expansion joints. Very good flexibility at high pressures is guaranteed (the bursting pressure is at least three times higher than the nominal pressure). And also large movements are compensated despite the extremely compact design. But the elements are not able to sustain twisting, for such purposes it is necessary to choose a different design solution.


The metallic flexible elements with sizes from DN 6 to DN 300 are available in four basic versions, namely:

Type KBN 1 - standard hoses with central crimp and the average thickness of the rid;

Sizes from DN 6 to DN 150 are always in stock , DN 200 , 250 and 300 – on request .

Type KBN 2 – heavy duty hoses; mainly used for high pressure conditions, with one or two braids , out of stock , available on request.

Type KBN 3 - hoses with narrow crimp; applied in cases of small bending radius is required, out of stock, available on request.

Type ZW 22 - a hose with a double sidewall, is used in special cases of high dynamic stress, vibration etc., out of stock, available on request.


Because of the high movement absorption capability of the metallic flexible elements compared with single-walled bellows to take up movements resulting from heat expansion or vibration. In plant with restricted space often one is dependent on the use of multiply expansion joints. Costs are saved because of smaller face-to-face und outer dimensions of the bellows. The low displacement forces of the multiply expansion joints reduce the loading on the pipe fixation points, thus allowing cost savings with minimum space requirements. For example, articulated joint systems with minimum limb lengths.


For corrosion protection

Various materials can be used for the bellow to avoid the risk of corrosion. The anticorrosive barrier against aggressive media can be a single, relatively thin, and thus inexpensive, layer.


For overpressure

The Metallic flexible elements can be used for vacuum and for pressures up to for example 720 bar test pressure, depending on the diameter. With careful dimensioning and design the expansion joint can also be used for applications with external pressure.


For extreme temperature conditions

With appropriate material selection the flexible elements can be used for temperatures ranging between 220°C and 1100 °C. With suitable refractory lining - even higher temperatures are possible.


For vibration damping

Any kind of oscillation should be avoided because it generates noise and vibration. Oscillation is eliminated by two methods. In the first place, the source of oscillation has to be designed in such a manner that as little as possible oscillation is transferred to installations, connections, pipe lines etc.

The second place vibrating machines such as blowers and fans, compressors, combustion engines etc. can be isolated from other parts of the installation and buildings. Thus, vibration is not transferred to the whole plant and buildings. The multiple springs reduce structure-bom noise similar to rubber elements by up to 20 dBA.

Angular and pressure compensated flexible elements are technically the best oscillation dampers. Braces are placed in such a manner that any vibration must be eliminated over the bellows and cannot propagate via the pipe line.


In high and ultra-high vacuum applications

Special demands are set on purity of the used materials, the surfaces and welding methods. For this reason a thorough compliance with every single process steps and the used materials of the end connections determined by the customer have significant importance.


Specific requirements for surface quality are as follows:

  • gas tightness;
  • clean and smooth surface;
  • minimum foreign gas content;
  • low vapor pressure under all operating conditions;
  • Chemical resistance, temperature stability and mechanical stability may be additional requirements.


For the production of metal expansion joints used three basic types of material, namely:

  • For most of the bellows used materials DIN 1.4541; 1.4404 and 1.4571 (AISI 321, 316L and 316Ti).
  • Braid Material is DIN 1.4301 (AISI 304).
  • The material AISI 316Ti used for special applications.

Rubber Expansion Joints by Ditec — Dichtungstechnik GmbH, Germany


Universal genius in measure and flexibility

In their material design and type of movement, our rubber expansion joints are genuinely multi-talented in terms of temperature, pressure and pumped fluid resistance. They require a great deal of both universal and specialist know-how, and constitute by far the largest share of our production.

Rubber expansion joints compensate for axial, lateral and angular movements resulting from thermal changes in pipeline length. They prevent the transmission of mechanical vibrations from machines, apparatus or pumps to the connected pipeline. They compensate for tension and imprecision in assembly, and are now able to withstand – depending on the application requirement – pressures of up to 40 bar.

In our production process, we produce single pieces and series with a diameter of up to 5 metres, individually designed and dimensioned on the basis of the Pressure Equipment Directives. Moreover, we are now the only major rubber expansion joint manufacture that continues to manufacture exclusively in Germany – at the cutting edge of development right in our own hometown factory.

Depending on the movement and installation position between the sliding and fixed bearings of a pipeline, we deliver rubber expansion joints with and without axial tie rods, manufactured to fit precisely. 

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Fabric Compensators Kompaflex - D.M.M. potrubn? elementy spol. s r.o., Slovak Republic


The technical fabric compensators (TFC) have proved successful in the equipment transporting gas agents at temperatures up to +1200 °C and pressures up to 0,1 MPa (gauge pressure 1 bar), in ducts having large axial movements with often occurring lateral and/or angular movements.

Such operating conditions can be found mainly in:

  • thermal power plants (with the coal-, oil- or gas-fired boilers), nuclear power plants,

  • natural gas combustion turbines,

  • chemical plants,

  • denitrification (DENOX) and desulphurisation equipment,

  • waste incinerators and flue gas treatment plants,

  • oil refineries, petrochemical equipment,

  • cement kilns and lime kilns,

  • pulp and paper industry,

  • metallurgical works and facilities with industrial furnaces,

  • air-conditioning, dust exhausting and filtering equipment,

  • lacquer paint shops and dryers,

  • industrial stacks constructions, and practically in any ducts through which hot gaseous agents are being transported.

It should be noted that the TFC, as compared to metal sheet or rubber compensator, should find better use in those applications, where there are large and complex movements of pipes installed inside the buildings with relatively small internal space.

The dimensions and conditions for deployment of the TFC in industrial installations are individual like are the pipeline systems and the wishes of particular customer. Therefore, it is not feasible to offer standardized "catalogue + tables" TFC solutions, and any TFC solution has to be customized to the existing basic constructions at the customer´s site.

Each TFC unit usually consists of several layers. There are sealing films, layers of carrier fabric which can sustain thermal and mechanical stress. All components and materials contain no asbestos as a matter of principle. In majority of cases the individual layers are not mutually connected inside the bellows (they are not glued or sewn together). However, the individual layers are joined together at their clamping edges because of transport reasons.

The dimensions and geometrical shape, the material composition and succession of individual layers are designed individually in each application case. The key assumption for an optimum TFC design is the set of precise technical data provided by the customer, the designer or engineer any of those, who are supposed to know well their own equipment.

And this is also our most important task - to acquire as much as information as possible about the equipment operating conditions which enables us to elaborate supply offer of high quality and to manufacture suitable TFC units. In addition to our rich experience with the old type compensators which usually have to be retrofitted, the following criteria are considered during the design stage of each new TFC:

  • original composition of materials,

  • possible causes of damages,

  • equipment operating parameters - operation in base-load regime or the equipment being switched daily on and out,

  • occasional problems with the steel parts located in the TFC - steel pipe joint area,

  • external factors which were neglected during the design stage of the former compensator, whose effect was noticed only after commissioning of the equipment.

The main criteria which are necessary for the design of the suitable compensator are listed hereunder. The knowledge of these criteria shall help to solve the problem and it should help to develop quick and optimum engineering and constructional solutions.

 Selection and dimensioning criteria

  • installation site:
    Indoor / outdoor installation, accessibility of the installation site and / or the respective location for
    maintenance and inspection of particular TFC.

  • type of transported agent:
    This parameter is important to select the suitable composition of materials from which the soft TFC is manufactured, whereby the data on casual surpassing of dew point (origin of condensate) and the effect of the chemical substances (chemical analysis of the transported agent should be included) largely facilitate and effectuate the constructional design and technical solution of encountered problems.

  • transported agent mass particles contents:
    This parameter essentially affects the composition (type and thickness of the surface finish) of the material used for the TFC manufactured as well as its construction and/or the respective steel parts/ guiding steel plates, whereby the key importance is assigned to the data on the mass particles contained in transported agent - mass concentration [mg/ Nm3], size distribution of particles and the direction of flow [upwards, downwards].

  • temperature:
    Likewise as the type of transported gas agent affects the choice of materials used for the TFC, the exact data on operating temperature, outdoor temperature, temperature on the TFC surface and on the TFC edges clamped on the solid duct and the emergency temperature limit, allow us to design the right materials and construction which is customized to the actual needs without superfluous and uneconomical over dimensioning.

  • pressure:
    The exact data on operating pressure - overpressure/ under pressure (normal, maximum value), pressure deviations, pressure surges, testing pressure - allow the engineer to select the right type of construction with the correct dimensions.

  • movements:
    Specification of the movement type (axial, lateral or angular), the movement amplitude and frequency affects not only the constructional design of the compensator, but it also determines the necessary mounting dimensions, therefore an increased attention should be paid to specification of these data.

  • flow rate of transported agent:
    The gas flow rate determines not only the type materials selected for the manufactured compensators, but it also determines the type of the metal parts used in the TFC construction. Anyway, by the flow rates above 10 m/S we recommend to use the guiding metal sheet plate or internal shielding tube to protect the soft compensator parts, to reduce the gas pressure drop and to eliminate unwanted flow turbulence.