The great thing about an expansion joint is that it can relieve stress in pipes and prevent the flange gaskets from being crushed. The two expansion joints to choose between are rubber and metal expansion joints. Both have their uses and the best one to choose is based on many factors.
Some Joints Use Both Rubber And Metal
A rubber expansion joint is made with natural or synthetic elastomers and is sometimes reinforced with metal. Metal is added depending on the vibrations that the expansion joint is subjected to and based on thermal movements.
Metal expansion joints are not only designed to absorb thermal movements, but also mechanical movements. This can make this option superior under some circumstances. However, rubber expansion joints can be designed that use metal so that the best characteristics of both products can be used in one product.
Rubber Handles Lateral Movement Better
Rubber joints have the ability to absorb lateral movement much more effectively than metal joints. There are also metal joints that are designed to handle lateral movements, but they are more complicated in design and can be more expensive.
Metal Is Stiffer
Both metal and rubber experience thrust forces when they are pressurized. These must be accounted for with the system design. However, metal joints are a lot stiffer when subjected to lateral movement and therefore have a lower lateral movement ability.
Metal Produces More Noise
Metal expansion joints produce noise as a result of vibration that is not only distracting, but that can also be damaging to the device. Rubber is better able to absorb vibrations, which leads to the joints not generating as much noise.
Rubber Has Thicker Walls
Rubber expansion joints have thicker walls than metal expansion joints. This allows for the rubber joints to better resist corrosion and abrasive liquids. Therefore, rubber is ideal under conditions that are highly corrosive. It is possible to expand the life of the metal expansion joints with drop-in liners, but this is less convenient.
Rubber Has A Longer Fatigue Life Cycle
Metal expansion joints have a shorter fatigue life cycle as a result of excessive movement, which is not a problem with rubber expansion joints. The rubber joint acts as a dampener that reduces movement and prolongs the life of the joint.
Rubber Is Easier To Install
It is much easier to install rubber joints thanks to them being lighter. Because the joints do not require extra gasketing, they can be installed much more quickly. While there are some similarities between metal and rubber expansion joints, rubber is often the better option.