Rubber expansion joint is made of rubber, which compensates axial, angular and lateral movements resulting from thermal changes in pipeline length, thus preventing transmission of mechanical vibration from machines to connected pipeline. This article focuses on the construction, installation and property for the expansion joints that are made from rubber.
Rubber expansion joints are devised for piping works consists of flexible main shell made of synthetic rubber with inner reinforcement, in order to provide steadiness, and pipe connections by means of loose flanges. These joints are easy to install due to relative small space requirement and light weight. The importance of these expansion joints are enormous in today’s industry, as these joints protect high valued equipment and installation and provide numerous benefits, when installed in rigid piping system.
The quality of the joints is backed up with strict quality procedures. The whole process commences with the selection of raw material in form of powder, which is mixed with other materials to form the bonding, vulcanization and cooling.
The rubber expansion joints are divided in two main categories namely hand builds one and molded expansion joints. The inside rubber lining has leak proof and made of synthetic or natural rubber depending on application. This also applies for the outside rubber cover, which plays the primary role to protect the canvas, between the inside lining and cover.
The construction materials help to protect the joints from outside damage. There are special polymers, which are supplied to resist the couplings from getting damaged from ingredients like chemicals, oils and fumes. The pressure supporting canvass consists of metal and fabric reinforcement, as wire or solid things.
Fix Points, Anchoring
There are fixed points to the anchor, which absorbs the reaction forces. These joints have been installed between two fix points. The immediate fix points are once just absorbing forces by friction of guide and joint stiffness, whereas main points are absorb the forces that are caused by internal pressure, weights and centrifugal force.
These are normally located in pump valves, bends, crosses line, thus ending the flow section of pipe work.
Installation Guideline for absorbing noise and vibration
These rubber expansion joints are installed in pump groups in order to absorb noise and vibration. These joints should be installed near the pump group leaving some distance. More distance is left in case of abrasive media. The pump group must be properly anchored in order to absorb the reaction and another fix point must be set immediately on the pipe.
Proper guiding is also necessary to ensure equipment work in a correct manner. If main fixed points could not be sized to absorb the reaction force caused by internal pressure limit rods can be used to relieve them from such forces.
Main Purpose Of These Joints
- These joints are used to accommodate compression and thermal expansion.
- It reduces the tension in the pipeline.
- These are used to prevent the noise and vibration in order to protect the connected system.
Property Of This Coupling
These expansion joints are manufactured from various types of rubber namely CR rubber, EPDM ,Nitril NBR, vitron FPM.
The neoprene CR rubber joints have excellent weather resistance capacity with great gasoline resistance. The EPDM has ozone and sunlight resistance that is suitable for most chemicals with great electric insulation. The Nitril NBR has good abrasive resistance. The viton FPM are suitable for chemicals and solvent, while the PTFE has outstanding resistance for all media.
Boson Engineering provides the best rubber expansion joints for various uses. If one want to know more, then log on to the website.