Rubber Bellows & Expansion Joints

1. Rubber Bellow: A rubber bellow, also known as a rubber expansion joint, is a flexible connector fabricated from natural or synthetic elastomers and fabrics with metallic reinforcements designed to provide stress relief in piping systems due to thermal and mechanical vibration and/or movements. They are flexible, which allows for compression, extension, and angular movement. They are often used in systems where there are large amounts of vibration, such as pumps or compressors. Additionally, they can also be used in systems where there is thermal expansion, as the rubber can expand and contract with temperature changes.
2. Expansion Joint: An expansion joint is a general term that refers to any device that allows for movement due to thermal expansion and mechanical vibration in a piping or ducting system. This can include rubber bellows, but it can also include metal bellows, and other types of expansion joints made from various materials like fabric, PTFE (Teflon), etc. There are also different types of expansion joints designed for different types of movement, including axial, lateral, and angular expansion joints. They are typically used in large-scale industrial applications, such as power plants or chemical processing plants, where there is a need to accommodate large amounts of thermal expansion and contraction.

1. Natural Rubber (NR): This is used for its high elasticity, excellent tensile strength, and resistance to abrasion and fatigue. However, it’s not very resistant to oils and certain types of chemicals.
2. Neoprene (CR): Neoprene is a general-purpose elastomer with good mechanical properties, and it’s resistant to weathering, ozone, and ageing. It’s also resistant to many chemicals and oils and can operate at a wide range of temperatures.
3. Nitrile (NBR): Nitrile rubber is highly resistant to oils and fuels, making it ideal for oil and gas applications. It also has good mechanical properties and can operate at various temperatures.
4. Ethylene Propylene Diene Monomer (EPDM): EPDM has excellent resistance to ozone, weathering, and ageing. It also has good resistance to many types of chemicals, but it’s not suitable for use with oils and fuels.
5. Styrene-Butadiene Rubber (SBR): SBR is a general-purpose rubber with similar properties to natural rubber. It has good abrasion resistance and excellent impact strength.
6. Silicone (VMQ): Silicone rubber can operate at high and low temperatures. It’s also resistant to weathering, ageing, and sunlight, but it’s unsuitable for oils and fuels.
7. Fluorocarbon (FKM, also known as Viton): Viton is resistant to a wide range of chemicals and oils and can operate at high temperatures. However, it’s not as flexible as some other types of rubber, and it’s more expensive.

It’s crucial to carefully consider the application’s specific requirements when selecting the material for the rubber below, as each type has its strengths and weaknesses.