Bellows expansion joints for heating networks: description and purpose

Bellows-type compensators are well suited for heating networks. There are many types of devices that differ in parameters and constructive elements. The peculiarity of these models is that they are able to withstand a high temperature. In order to understand this question in detail, it is recommended that you familiarize yourself with the types of compensators.

Types of devices

According to the design, axial and flanged bellows expansion joints are designed for heat networks GOST R 50671-94. There are models of low and high pressure. Flanged devices are divided into shear and angular models. In a separate category, cardan and block modifications are distinguished.

Low-pressure devices

Low-pressure models are actively used in heating networks. Steel in this case uses different markings. If we consider the modifications of the OFN series, they have a wide output. The index of axial travel is on average 80 mm. Their stiffness coefficient is low. The maximum permissible temperature of the compensators of the specified type is at the level of -10 degrees.

Also it should be noted that there are modifications with holes. They are suitable for pipes with a diameter of 3 cm. Their stiffness coefficient is on average 300 N. The weight of the conventional model is 10 kg. If we consider the compensator CSR, it has four holes. The exit in this case is a width of 80 mm. The maximum pressure is 1.2 bar.

High-pressure models

Bellows expansion joints for high-pressure heating networks are made only of hardened steel. The minimum permissible temperature of the compensators is no more than -20 degrees. It is also worth noting that there are modifications with high axial travel. Most devices are made with a wide output. Holes can be located at a great distance from the reinforcement.

On average, the width of the inlet is 70 mm. The stiffness index of the models starts from 400 N. The pressure parameter at the output is approximately 2.5 bar. If we consider the compensator CSR, it has five holes. The parameter of the axial movement is 40 mm. The weight of the model is exactly 10 kg. Steel in this case is applied with the marking 12X. The maximum permissible temperature of the specified compensator is 430 degrees.

Axial models

Compensator bellows (axial) is made with a long holder. Racks for modifications are made with a wide output. Models are great for heat insulation pipes. Steel in devices is of different types. Modern models are made with holes. The limiting pressure of the compensators is at least 4 bar. The entrance, as a rule, is provided for 55 mm. The stiffness coefficient on the average is 340 N. It should also be noted that the models have a high permissible temperature. If we talk about the minuses, the attention deserves the fact that the devices weigh a lot. Also, socialists dismiss that models can not be used for aluminum pipes.

The compression force in this case is very large. If we consider the bellows expansion joint (axial) series RK, it has an output of 56 mm. In this case, the mass of the product is 12 kg. Additionally, experts point out the low conductivity of the device. The minimum allowable temperature of the compensator is at -20 degrees. The device is excellent for heat insulation pipes. The device is fixed with a harness. The clamp in this case is selected by two screws. There are no holes in the presented modification. The inlet is used at 28 mm. The stiffness parameter of the device is 300 N. The main stroke for 1000 cycles is approximately 400 mm. The maximum permissible temperature for compensators of this type is 340 degrees. However, in this case everything depends on the manufacturer and the marking of the steel used.

Purpose of flange devices

Flanged bellows expansion joints for heating networks are suitable for pipes of different diameters. Most often devices are used to connect steel pipes. Many modifications are made of steel series 17 GS. Most devices have a wide output. The maximum allowable temperature of the compensators is 340 degrees.

Also it should be noted that there are models with narrow channels. The armature is always made of steel. Some devices are manufactured with seals. The output from them, as a rule, is set with a diameter of 50 mm. The axial stroke for 50 cycles is no more than 80 mm. The weight of the conventional model is approximately 8 kg. The minimum allowable temperature of the expansion joints is -20 degrees.

Shifting devices

Shift bellows expansion joints for heating networks have movable tips. Modifications are made in different sizes. Modern models are made with a wide holder. Also it should be noted that there are models with a narrow output. The average diameter of the tube is 80 mm. The axial stroke reaches a maximum of 20 mm at 100 cycles. The weight of the conventional model varies around 8 kg. The limiting pressure is about 3.3 bar. There are modifications with and without tips. It should also be noted that the compact modifications are on the market. If we consider the model of the SCU PPU, it has an outlet with a tube. Steel, as a rule, is applied to the 17G series. The maximum allowable temperature of compensators of this type is 450 degrees.

Angle Models

Corner bellows expansion joints for heating networks have recently been considered very popular. They use one rack. Steel is used in different series. Standard models are made with short holders. Also it should be noted that there are modifications with a wide output for heat-insulating pipes. The inlet for such models is approximately 65 mm. The axial stroke with 50 cycles is not more than 80 mm. The weight of the conventional model is approximately 7 kg.

Also it should be noted that there are devices with holes. The limiting pressure at them reaches 3.5 bar. The minimum allowable temperature for compensators of this type starts from -20 degrees. Still there are modifications with short tubes that weigh little. If we consider the bellows expansion joint, it has five holes. At the same time, the mass of the modification is exactly 10 kg. The stiffness coefficient in the device is reached 322 N.

Purpose of cardan devices

Cardan models are perfectly suitable for heating networks. In this case, the pipes are fixed very quickly. Some modifications are made with a short rack. The holders are fastened to the sides. Also it should be noted that there are devices with a wide output. The holes are located on the counter. The weight of the standard device is 7 kg. The stiffness coefficient depends on many factors. Also it should 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 used in the 17G series.

Thermally insulated modifications

Thermally insulated models are in great demand. They use a very rigid rack. Also it should be noted that there are models with short racks. In this case, the tubes are installed in a wide outlet. The weight of the standard model is 12 kg. It should also be noted that the output is used with a diameter of 60 mm. These devices are perfectly suited for heat-insulating bent pipes.

Holders are of different shapes. The stiffness coefficient of the modifications starts from 400 N. The insulation of bellows expansion joints is made with a sealant. Some models can boast of their strength. The minimum permissible temperature of the standard compensator is -10 degrees. Holes in this case are on the counter. The most common are devices with one output. The maximum permissible temperature for compensators of this type is 340 degrees. Also there are models with a high coefficient of rigidity. On average, the weight of such products is 15 kg. Steel at the same time applies the series 18G.

Block Models

Block modifications are very common and meet the standards of SNIP (heat networks). Steel they have a series of 09GS. Also there are modifications with extension cables. Devices are often used for curved pipes. The axial stroke at 50 cycles is on average 70 mm. The weight of the standard model is 9 kg. The output in devices starts from 70 mm. A conventional 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 of the expansion joints is 60 mm. If we consider compensators in PPU insulation, they have four holes. The weight of the device is 9 kg. The stiffness coefficient of the presented modification is located at 430 N.

Start modifications

Starting devices are distinguished by the presence of a wide output. Rack models are of different thicknesses. Also it should be noted that modifications are made with rigid fixatives. Most models are made small. On average, the standard modification weighs no more than 8 kg. It should also be noted that steel, as a rule, is applied to the 17G series. The inlet diameter of the models does not exceed 65 mm. The stiffness coefficient starts from 300 N. The axial stroke of most devices does not exceed 20 mm.

Rotary Models

Rotary models that comply with the accepted standards of SNIP (heat networks) are well suited for connecting curved pipes. The models produce racks of different lengths. There are modifications to 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 permissible temperature of the compensator is -10 degrees.

Also there are modifications with a narrow output. They have two racks. The device is fixed to the screws. Models are not bad for curved pipes. It is also worth noting that there are compensators on wide stands. The average yield is 60 mm. At the same time, the stiffness coefficient starts at 320 N. Experts say that the models are very easy to install. In addition, it is important to consider the high temperature parameter.