AXIAL EXPANSION JOINT - AR
These expansion joints are used for compensation of movements (compression and/or extension) along the longitudinal axis. Also, under certain conditions, with structural adaptions, these expansion joints can compensate smaller values of lateral and angular movements. Axial expansion joints can be supplied with flanges or with welding pipe ends, or in combination of these two. Expansion bellows (flexible element of expansion joint) is made of stainless steel, and if needed, from nickel alloys, while the connecting elements (flanges, pipe ends) are made of carbon steel, and also from stainless steel, depending of the requirements and purpose. Axial expansion joint is pressure-unrestrained and must be positioned in the pipeline between two fix points with proper pipeline guidance. Axial expansion joints in their construction can have various additional elements in addition to above mentioned, such as an internal sleeve, external protection, internal guides, anti-torsion system etc. Such axial expansion joints with additional elements are often used in district heating networks.
Axial compensators are supplied with flanges or with pipe connections for welding, or a combination of the two. The bellows (flexible element of the compensator) is made of stainless steel, and if necessary, from nickel alloys, while the connecting elements (flanges, pipe connections) are made of carbon steel, and also from stainless steel, depending on the requirements and purpose.
The axial compensator is pressure-uncoupled and must be positioned between two solid points in the pipeline with proper pipeline routing.
Axial compensators can have various additional elements in their construction in addition to the above, such as an internal guide sleeve, external protection, internal guides, anti-torsion system, etc. A common application of such axial compensators with additional elements is in heating main pipelines.
UNIVERSAL EXPANSION JOINT - UD
The purpose of these expansion joints is to compensate axial, lateral and angular movements. Universal expansion joints are often used in exhaust systems and in all low-pressure systems with combined displacements. Like the axial expansion joint (AR), the universal compensator is pressure- unrestrained.
HINGED EXPANSION JOINT - HS
This expansion joint is designed to compensate angular movements in one plane. It is pressure-restrained so that there is no transfer of the force from the internal pressure from the expansion joint to other pipeline elements, which is advantageous in situations where it is not possible to make robust fixed points. Single hinged expansion joint must be combined with other expansion joints, usually it is pair of them (2xHS), three hinged expansion joints (3xHS), in a pair with two gimbal expansion joints (1xHS + 2xGS) and in a pair with one of the double lateral expansion joints (HD, GD, TD).
GIMBAL EXPANSION JOINT - GS
The gimbal expansion joint is intended to compensate angular movements in any plane. Like the hinged expansion joint (HS), the gimbal is not used alone but in pair with the same (2xGS) or in combination with hinged expansion joint (1xHS + 2xGS).
DOUBLE HINGED LATERAL EXPANSION JOINT - HD
Double hinged lateral expansion joint is a structure made of two single hinged expansion joints (HS) connected with centre pipe, which makes the assembly intended for compensation of lateral displacements in one plane. By defining the length of the centre pipe, this expansion joint is capable to compensate large values of lateral movements.
DOUBLE GIMBAL LATERAL EXPANSION JOINT - GD
By combining two gimbal expansion joints (GS) connected with centre pipe into the assembly, a double gimbal lateral expansion joint is obtained, intended for compensation of lateral movements in any plane. Like expansion joint type HD, this expansion joint is suitable for compensation of large lateral displacements.
SINGLE TIED LATERAL EXPANSION JOINT - TS
This expansion joint is used for compensation of small lateral displacements and vibrations. It is restrained with tie rods so that the force from the internal pressure is not transferred to other parts of the system. The most common application of this type of expansion joint is the elimination of vibrations, so these compensators are installed mainly on pumps, fans and similar equipment that produce vibrations during their work.
DOUBLE TIED LATERAL EXPANSION JOINT - TD
The purpose of this expansion joint is to compensate lateral movements in any plane and also angular displacements. The compensation possibility, or the amount of the lateral movement, is most significantly influenced by the length of the centre pipe, so this expansion joint can also compensate large values of lateral displacements. However, due to the compactness of the construction in such situations, we still recommend the use of expansion joints type HD and GD.
DOUBLE TIED LATERAL EXPANSION JOINT (WITH 3 OR MORE TIE RODS) - TM
The difference compared to the previous model is in the number of the tie rods and in the fact that a compensator with more than two tie rods is not capable to compensate angular movements. Usually, the TM construction is practiced on expansion joints of larger diameter and higher pressures compared to the TD.
EXTERNALLY PRESSURIZED AXIAL EXPANSION JOINT - AE
This expansion joint is used when having combination of high operating pressure in the pipeline and large axial displacements. In such situations, the designer is usually faced with the problem of how to make the bellows stable, and with this construction and the transfer of the medium (pressure) to the outer area of the bellows, the stability problem is solved.
CENTRAL HEATING EXPANSION JOINT - AS
This expansion joint belongs to the group of expansion joints exclusively for compensation of axial displacements, like the previous type AE, and as its name suggests, its most common application is in central heating systems. The standard range of this type of expansion joint is from DN15 to DN50, it is delivered in a factory pre-stressed condition so that it compensates exclusively axial displacement in compression. The pipe ends can be designed for welding connections and also as pipe thread connections.
MAX-COMP EXPANSION JOINT - MC
Expansion joint type MAX-COMP is a type narrowly specialized for heating systems. It is intended to compensate exclusively axial displacement, as in the previous type (AS) in terms of compression. The expansion joint is made in a robust construction with an external cover, it is self-guided, with expansion bellows protected from torsional loads. Also, the design does not allow bellows to have displacements greater than those defined by the design. The expansion joint type MAX-COMP is most often installed in pre-insulated underground pipelines.
ONE-CYCLE EXPANSION JOINT - OC
The one-cycle expansion joint is used in pre-insulated pipelines for thermal pre-stressing before the system is put into the operation. After the installation process is completed, this expansion joint no longer has a function in terms of permanent compensations by the expansion bellows.
PRESSURE BALLANCED EXPANSION JOINT - PB
The special construction of this expansion joint allows it to compensate all kind of movements, lateral, angular and axial, which makes this expansion joint the only one of the restrained type (restrained force from internal pressure) that is capable to compensate axial movements. It is most often used in systems where the installation of fix points is difficult or not feasible, and with equipment that does not allow excessive loads on itself, such as turbines, pumps, compressors, valves etc. Pressure balanced expansion joints can be divided into two basic groups, depending on the configuration of the pipeline where they are installed, into the elbow type and the so-called IN-LINE type. Also, depending on the purpose, the construction, starting from the total number of the bellows to the design of other elements, can vary. Pressure balanced expansion joints can be designed with welding pipe ends or with flanges and in combination.
MOUNT-DEMOUNT EXPANSION JOINT - DK
This type of expansion joint is used during assembly and disassembly activities, replacement of individual components in the system such as valves, pumps, etc. The expansion bellows is bridged by connecting bolts, so the expansion joint does not have the function of compensation of thermal or mechanical dilatations of the pipeline, but serves exclusively to axially compress the expansion joint by releasing the bolts and compressing it using compression bolts, thus ensuring the necessary clearance for removing equipment from the system. The mount-demount expansion joint can also be used to solve minor axial misalignments of the pipeline.
RECTANGULAR EXPANSION JOINT - PK
Rectangular expansion joints are most often used in low-pressure ventilation systems, exhaust, air and other gas ducts and in vacuum systems such as condensers. They can be of various designs, with one or two expansion bellows, with welding ends or with flanges. The ducts where these expansion joints are used do not have to be exclusively rectangular or square shape in cross-section, but also of more complex shapes. The displacements that can be compensated by this type are axial, lateral and angular, and they define the design that needs to be achieved for the expansion joint to perform its purpose.
VALVE BELLOWS - VB
This expansion joint is used in valve assemblies and serves as a sealing element. Opening and closing, or the passage of media through the valve, is achieved by compressing and expanding the bellows.