Hanwel delivers a wide range of products that we have housed in the following main groups:
• Pipe supports
• Expansion joints
• Piping systems
The necessary steps for installing all expansion joints shall be pre-planned. The installers shall be made aware of these steps as well as the installation instructions furnished by the manufacturer. The most critical phases of the expansion joint installation are as follows.
Care shall be exercised to prevent any damage to the thin bellows section, such as dents, scores, arc strikes and weld spatter.
No movement of the expansion joint (compression, extension, offset, rotation and especially torsion) due to piping misalignment, for example, shall be imposed which has not been anticipated and designed into the movement capability of the expansion joint. If such movements are imposed, they can result in system malfunction, damage to the bellows or other components in the system. Specifically, cycle life can be substantially reduced, forces imposed on adjacent equipment may exceed their design limits, internal sleeve clearances may be adversely affected, and the pressure capacity and stability of the bellows may be reduced.
Any field pre-positioning shall be performed in accordance with specific instructions which include both the direction and magnitude of the movement.
Anchors, guides and pipe supports shall be installed in strict accordance with the piping system drawings. Any field variances from planned installation may affect proper functioning of the expansion joint and must be brought to the attention of a competent design authority for resolution.
The expansion joint, if provided with internal sleeves, shall be installed with the proper orientation with respect to flow direction.
After the anchors or other fixed points are in place and the piping is properly supported and guided, the expansion joint shipping devices should normally be removed in order to allow the expansion joint to compensate for changes in ambient temperature during the remainder of the construction phase.
The number of tie-rods is determined by the design pressure of the expansion joint. It can range from two to eight tie-rods in extremely high pressure conditions.
Metal pipes have the property to expand or shrink at temperature changes. In the calculation of the exposure, the temperature difference, the coefficient of expansion and the length of the conduit are relevant parameters.
The coefficient of expansion depends on the material of the pipe and the temperature.
The formula for calculating the expansion of a pipeline:
D=0,01 x L x Dt x a
L = length of the pipe in meters
Dt = temperature difference (° C)
a = coefficient of expansion (mm / m ° C)
D = expansion
Expansion joints are maintenance free. They can only be tested if the expansion joint is supplied with 2-ply testable bellows using vacuum or air pressure testing.
Piping systems in which expansion joints are installed must be limited by fixed points. These fixed points must be constructed in such a way that they can resist the forces of the expansion joint and the resistance of the guide points.
The number of expansion joints used on a pipe depends on the length of the pipe, the pressure, the temperature, and the size. Upon knowing these design conditions, we can inform you of the number of expansion joints the pipeline requires.
These compensators are not only applicable in the chemical and petrochemical industry, as well as in flue gas, and in the food and pharmaceutical industries.
In power plants, waste incineration plants, blast furnace plants, cement factories, paper mills, industrial furnaces, fan connections, General machine and equipment for the chemical and petrochemical industry.
Fabric expansion joints absorb both axial and lateral movements as angle changes. The fabric expansion joints have a movement absorption capacity between 10% and 75% of construction length and also have an extremely low movement resistance.
Fabric expansion joints are only suitable for gaseous media such as flue gas and air. A Hanwel fabric expansion joint is always custom made, whereby the structure is determined based on temperature and medium.
Stainless steel expansion elements are used in exhaust systems or high pressure systems and at temperatures up to 600 ° c. These metal expansion joints or metal expansion pieces are, in diameters from 20 to 3000 mm, delivered with flanges or weld ends according to customer specification or standard dimensions.
Rubber expansion joints are used in air conditioning systems, cooling water/condensate pipes, pipelines between turbine and compressor, flexible pump connection at heating systems, pipelines for freon, water, air, hot gases, chemicals, transmission lines for paper pulp, air and liquid pipe systems on ships and district heating pipes.
Hanwel has a extensive programme of expansion joints and can advise you the appropiate extension joint, focused on the application and the specific circumstances.
Compensators are used in absorbing vibrations, reducing noise, expansions and shrinkage. As a result, the stresses can be limited in the pipe.
They absorb axial and lateral, as well as angular movements. Also, reaction forces by tie rods or other external features, such as hinged or gimbal structures are limited.
The rubber expansion joints can also be provided with tie-rods, ground covers, and all other elements which may be necessaryfor the rubber expansion joints in order to be optimally applied.