Bellow type expansion joints are great for heating networks. There are many types of devices that differ in parameters and design elements. The peculiarity of these models is that they are able to withstand high temperatures. In order to understand this issue in detail, it is recommended to familiarize yourself with the types of compensators.
Types of devices
According to the design, axial and flange bellows expansion joints for heating networks GOST R 50671-94 are distinguished. There are low and high pressure models. Flange devices are divided into shear and angle models. Gimbal and block modifications are highlighted in a separate category.
Low pressure devices
Low pressure models are actively used in heating networks. Steel in this case is used in different markings. If we consider modifications of the OFN series, they have a wide output. The axial stroke averages 80 mm. Their stiffness coefficient is low. The maximum allowable temperature for this type of compensator is -10 degrees.
It should also be noted that there are modifications with holes. They are suitable for pipes with a diameter of 3 cm or more. Their stiffness coefficient is on average 300 N. The mass of a conventional model is 10 kg. If we consider the KSO compensator, it has four holes. The outlet in this case has a width of 80 mm. The pressure limit is 1.2 bar.
High pressure models
Bellow expansion joints for high pressure heating networks are made only from hardened steel. The minimum allowable temperature of compensators is no more than -20 degrees. It is also worth noting that there are modifications with a high axial stroke. Most devices are made with a wide output. Holes can be located at a great distance from the reinforcement.
The average inlet width is 70mm. The stiffness index for models starts from 400 N. At the same time, the outlet pressure parameter is approximately 2.5 bar. If we consider the KSO compensator, it has five holes. The axial stroke parameter is located at the level of 40 mm. The mass of the model is exactly 10 kg. Steel in this case is used with the marking 12X. The maximum allowable temperature of the specified compensator is 430 degrees.
Axis Models
Bellows compensator (axial) is made with a long holder. Racks for modifications are produced with a wide outlet. Models are great for heat-insulating pipes. Steel indifferent types of devices are used. Modern models are made with holes. The limiting pressure indicator for compensators is at least 4 bar. The entrance, as a rule, is provided for 55 mm. The stiffness coefficient is on average 340 N. It is also worth noting that the models have a high allowable temperature. If we talk about the cons, then the fact that the devices weigh a lot deserves attention. The socialists also note that the models cannot be used for aluminum pipes.
The compression force in this case is very large. If we consider the bellows (axial) compensator of the RK series, it has an outlet of 56 mm. In this case, the mass of the product is 12 kg. Additionally, experts point to the low conductivity of the device. The minimum allowable temperature of the compensator is -20 degrees. The device is excellent for heat-insulating pipes. The device is fastened with a harness. The clamp in this case is selected for two screws. There are no holes in the presented modification. The inlet is used at 28mm. The stiffness parameter of the device is 300 N. The thrust stroke for 1000 cycles is approximately 400 mm. The maximum allowable temperature for compensators of this type is 340 degrees. However, in this case, everything depends on the manufacturer and marking of the steel used.
Assignment of flange devices
Flanged bellows expansion joints for heating networks are suitable for pipes of different diameters. Most common devicesused to connect steel pipes. Many modifications are made from steel series 17 GS. Most devices have a wide output. The maximum allowable temperature of the compensators is 340 degrees.
It should also be noted that there are models with narrow channels. Their fittings are always made of steel. Some devices are made with seals. Their output, as a rule, is set with a diameter of 50 mm or more. Axial travel for 50 cycles is no more than 80 mm. The mass of the standard model is approximately 8 kg. The minimum allowable temperature of compensators is -20 degrees.
Shift devices
Shear bellows expansion joints for heating networks have movable tips. Modifications are made in different sizes. Modern models are made with a wide holder. It should also be noted that there are models with a narrow output. The average tube diameter is 80 mm. The axial stroke at 100 cycles reaches a maximum of 20 mm. The mass of a conventional model fluctuates around 8 kg. The limiting pressure in this case is about 3.3 bar. There are modifications with tips and without them. It should also be noted that compact modifications are presented on the market. If we consider the PPU SKU model, it has an outlet with a tube. Steel, as a rule, is used in the 17G series. The maximum allowable temperature for compensators of this type is 450 degrees.
Corner models
Angular bellows expansion joints for heating networks have recently been considered very popular. They use one stand. Steelused in different series. Standard models are made with short holders. It should also be noted that there are modifications with a wide outlet for heat-insulating pipes. The inlet for such models is approximately 65 mm. The axial stroke at 50 cycles is no more than 80 mm. The mass of the standard model is approximately 7 kg.
It should also be noted that there are devices with holes. Their maximum pressure reaches 3.5 bar. The minimum allowable temperature for compensators of this type starts from -20 degrees. There are also modifications with short tubes that weigh little. If we consider the PPU bellows expansion joint, it has five holes. In this case, the mass of the modification is exactly 10 kg. The stiffness coefficient in the device is 322 N.
Assignment of cardan devices
Gimbal models are great for heating networks. In this case, the pipes are fixed very quickly. Some modifications are made with a short stance. The holders are attached to the sides. It should also be noted that there are devices with a wide output. The holes are located on the rack. The mass of the standard device is 7 kg. The stiffness coefficient depends on many factors. It should also be noted that there are large modifications that are made of steel. They use an outlet with a diameter of 80 mm. Steel can be applied 17G series.
Heat-insulated modifications
Insulated models are in great demand. They have a very rigid stance. It should also be noted that there are models with short racks. At the same time, the tubesinstalled with a wide outlet. The mass of the standard model is 12 kg. It should also be noted that the outlet is used with a diameter of 60 mm or more. These devices are excellent for insulating curved pipes.
Holders are used in different shapes. The stiffness coefficient for modifications starts from 400 N. The insulation of bellows expansion joints is made with a seal. Some models are able to boast of their strength. The minimum allowable temperature of a standard compensator is -10 degrees. The holes in this case are on the rack. The most common are devices with one output. The maximum allowable temperature for compensators of this type is 340 degrees. There are also models with a high coefficient of rigidity. On average, the mass of such products is 15 kg. Steel is used in this series 18G.
Block Models
Block modifications are very common and meet the standards of SNIP (heat networks). Steel they use series 09GS. There are also modifications with extension cords. Devices are often used for curved pipes. Axial travel at 50 cycles averages 70 mm. The weight of the standard model is 9 kg. Output in devices starts from 70 mm. The regular model is made with one tube.
There are modifications with a long rack. There are devices with 4 and 8 holes. The minimum allowable temperature for compensators for this is 60 mm. If we consider compensators in PPU insulation, they use four holes. Weightdevice is 9 kg. The stiffness coefficient of the presented modification is at the level of 430 N.
Starting modifications
Starting devices are distinguished by the presence of a wide exit. The models have racks of different thicknesses. It should also be noted that modifications are made with rigid clamps. Most models are made small. On average, a standard modification weighs no more than 8 kg. It should also be noted that steel, as a rule, is used in the 17G series. The inlet diameter of the models does not exceed 65 mm. The stiffness coefficient starts from 300 N. The axial travel of most devices does not exceed 20 mm.
Rotary models
Rotary models that comply with accepted SNIP (heat networks) standards are well suited for connecting curved pipes. The models are made racks of different lengths. There are modifications for 4 and 8 holes. If we consider the devices of the PK series, they have a long tube. The stiffness coefficient does not exceed 340 N. The axial stroke at 50 cycles is 50 mm. The outlet in the device is 45 mm. In total, the model has four holes. The minimum allowable compensator temperature is -10 degrees.
Also there are modifications with a narrow exit. They have two racks. The device is fixed with screws. Models are well suited for curved pipes. It is also worth noting that there are compensators on wide stands. Average outlet diameterequals 60 mm. At the same time, the stiffness coefficient starts from 320 N. Experts say that the models are very easy to install. In addition, it is important to consider the high allowable temperature parameter.
