TUTORIALES

BASIC EXPANSION JOINT COURSE

Basic information for understanding what a compensator is, and which of its aspects are the most important.

1) WHAT IS A COMPENSATOR, AND WHAT IS IT USED FOR?

A compensator is an elastic element that allows independent movement of its two ends or flanges, preventing the transmission of any type of undesired or undesirable movement in the installation.

There are other names for compensator, such as expansion joints, and depending upon the specific type of element, they may also be referred to as “anti-vibrators”.

2) WHAT TYPE OF MOVEMENTS DOES A COMPENSATOR ABSORB?

The images that appear below are not the property of BIKAR lateral the two flanges move along parallel planes axial (compression and extension: the two flanges move along the compensator’s axis. This movement may be positive (extension) or negative (compression).

angular: one of the couplings moves in a direction forming an angle with the other.

rotational: one of the couplings rotates with respect to the other.

Vibration: a set of movements that occur very rapidly over time.

IMPORTANT NOTE: Not all compensators are able to absorb all types of movement (such as rotational in the case of metal compensators), and there are also movements that cannot be absorbed at the same time.

3) WHAT TYPES OF CONPENSATORS EXIST?

There are 3 main groups based upon the materials used in manufacturing: fabric, rubber, and metal.

4) HOW DO I CHOOSE THE RIGHT KIND OF COMPENSATOR?

The determining factors are: the temperature of the interior fluid, the pressure of the interior fluid, the type of fluid that will be circulating, and the location where the compensator will be installed.

In summary:

Since there are a multitude of materials that can be used to manufacture each type of compensator, in any of these cases it is best to have some guidance from an expert, who can determine which is the best option.

5) WHAT IS A 100% AIRTIGHT FABRIC COMPENSATOR?

In some installations, it must be ensured that none of the product circulating in the interior of the installation is able to escape into the atmosphere.

One very good example of this is with steel treatment facilities, where the interior atmosphere is highly enriched in N2.

This hazardous gas cannot be allowed to escape into the environment, even though the installation may have multiple pipe joints.

In cases like these the manufacturer of the compensators, which would typically be made with fabric, must be able to ensure that there is no amount of leakage, no matter how small.

There are specific manufacturing materials used for this type of application, which can support temperatures of up to 1000 ºC. After being manufactured, 100% of the pieces are tested to ensure their reliability.

6) HOW CAN IT BE DETERMINED WHETHER A COMPENSATOR IS DAMAGED?

For elements that are installed in a visible location, it is very easy to determine whether they are broken, by observing the presence of cracking on the surface or obvious leakage of heat, fluid, dust, etc. However, the most dangerous types of damage are not visible to the eye, since compensators are usually made from multiple layers.

Through the use of special testing tools, it can be determined whether these layers are damaged and whether, for example, an undesired leakage of heat into the atmosphere is occurring.

7) WHAT SHOULD I DO WITH A COMPENSATOR WHEN IT HAS REACHED THE END OF ITS USEFUL LIFE?

Compensators are made up of different materials, which become waste once its useful life has ended.

These wastes cannot be dumped into a regular landfill, but must be managed by professionals who are specifically qualified for this purpose.

Thanks to its ISO 14001:2004 certification, BIKAR has the knowledge required to carry out this management in an environmentally correct manner

8) WHAT ARE THE PIPE SUPPORTS AND HOW DO THEY INTERACT WITH THE COMPENSATORS?

The compensators can absorb deviations in any direction or along any plane, but the pipes must be controlled, as required by the direction of movement.

These elements that control the movement are known as “supports”.

The most typical examples are slide assemblies, guides, and supports.

For example, if axial compression must be absorbed, the pipe must be guided by these supports and allowed to move only in that direction.

Without these supports, the joint could become excessively elongated, with disastrous results.

9) WHAT IS THE ACTIVATION FORCE AND HOW DOES IT AFFECT THE INSTALLATION?

For a compensator, the activation force is defined as the minimum energy necessary to produce a deformation, whether axial compression or extension, lateral, or rotational.

This means that a compensator with a low activation force starts to deform before one with a high activation force does.

To put it another way, a compensator with a low activation force decreases the amount of forces that the pipe system must support.

This is valuable data for pipes made from plastic materials (GRP, PVC, etc.), which have weaknesses in the area of the flanges.

Using a compensator with a low activation force provides the following advantages:

• Better functional guarantee for a pipe installation.
• Lower manufacturing costs since pipes can have a lower thickness of reinforcement.
• Lower maintenance costs for the installation, since lower demands are place upon the structure.
• Longer useful life for the support systems from working with lower load stress.

Following this design philosophy, BIKAR has studied the geometry of its compensators and has achieved a considerable reduction in the activation forces for its products.

Consult with our Technical Department to determine the best solution for your needs.