Thermal growth, equipment movement, vibration or pressure pulsation may generate movement in a piping system. When this movement is not absorbed by the piping system itself, an expansion joint is the perfect solution.
A Rubber Expansion Joint is flexible connector fabricated of natural or synthetic elastomers, fluoroplastics and fabrics and, if necessary, metallic reinforcements used to absorb movements in a piping system while containing pressure and a medium running through it.
Absorb Axial movements (extension and compression).
Axial movement is the change in dimensional length of the bellows from its free length in a direction parallel to its longitudinal axis.
Absorb Lateral movements.
Lateral movement is the relative displacement of one end of the bellows to the other end in a direction perpendicular to its longitudinal axis.
Absorb Angular and Torsional Movements.
Angular movement is the rotational displacement of the longitudinal axis of the bellows toward a point of rotation. Torsion refers to twisting one end of the bellows with respect to the other end, about the bellows centerline.
Rubber expansion joints isolate or reduce vibration caused by equipment. The transmission of vibration is reduced and they protect equipment from these adverse effects.
Dampen Sound Transmission.
Rubber expansion joints tend to dampen transmission of sound because of the steel-rubber interface of joints and mating flanges
Reduced fatigue factor
Given the inherent characteristics of natural and synthetic elastomers, they are not subject to fatigue breakdown or embrittlement and prevent any electrolytic action because of the steel-rubber interface of joints and mating flanges.
Extraordinary resistance to abrasion and corrosion
A wide variety of natural, synthetic and special purpose elastomers and fabrics are available to the industry. Materials are treated and combined to meet a wide range of practical pressure/temperature operating conditions, corrosive attack, abrasion and erosion. See table of materials.
Minimal face-to-face dimensions while absorbing large movements
With a minimal face to face length the Rubber Expansion Joints provide superior movement capability in axial compression, axial extension, and lateral deflection, as well as in the angular and torsional direction.
Low Spring Rates due to inherent flexibility of rubber
The inherent flexibility of rubber expansion joints permits almost unlimited flexing to recover from imposed movements, requiring relatively less force to move, thus preventing damage to motive equipment.
No gaskets required for installation
Elastomeric expansion joints are supplied with flanges of vulcanized rubber and fabric integrated with the tube, making the use of gaskets unnecessary in most of the applications. Check assembly instructions before installation.
Rubber Expansion joints are relatively light in weight, contributing to lower installation labour costs.
Reduced Heat Loss
Rubber expansion joints reduce heat loss, giving long maintenance-free service.
MACOGA rubber expansion joints are designed following the guidelines of the FSA (Fluid Sealing Association) Non-Metallic Expansion Joints Technical Handbook, ASTM F1123 - 87 Standard Specification for Non-Metallic Expansion Joints and always complying with the European Pressure Equipment Directive 2014/68/UE for the specified operating conditions.
MACOGA Rubber Expansion Joints are manufactured considering:
Rubber Expansion joints are fabricated with an elastomeric tube reinforced with multiple plies of fabrics covered with synthetic rubber. The inner tube is made of natural rubber, synthetic rubber or blend of synthetic rubber. The fabrics are Nylon®, Polyester, Aramid or Kevlar®. An additional reinforcement to the fabric may be provided in the body of the expansion joint and may be solid metal rings or wire embedded in the rubber.
A rubber bellow is manufactured from independent rubber layers and reinforcements that are vulcanized together after being molded or formed.
With over 35 rubber elastomers available and the ability to further modify properties by compounding it can be challenging for non-specialists to select the most appropriate rubber polymer for their requirements. Our experts may assist our customers with material selection for a proper performance and to reduce the risk of failure.
Standard constructions normally utilize high quality synthetic fabric like Nylon®, Polyester, Aramid or Kevlar®. Fabric plies are impregnated with rubber or synthetic compounds to permit flexibility between the fabric plies.
Wire or solid steel strings are imbedded in the carcass and are used as strengthening members of the joint.
Carbon steel as standard. Also available in zinc plated or hot dip galvanized carbon steel, stainless steel, duplex, etc. Flanges drilled to EN, ANSI, JIS, AWWA standards or any specific dimension.
Temperatures listed above are the typical maximum degree ratings for continuous use.
Nylon ©, Polyester, Aramid or Kevlar ©
Wire or solid steel strings are imbedded in the carcass and are used as strengthening members of the Expansion Joint.
Our analysis and design practices include:
We use the most sophisticated analysis and calculation software to design pipe systems and select the most appropriate Expansion Joints providing a complete pipe stress analysis when required.
With our 3D mechanical CAD software our engineers design Expansion Joints to the same conditions that they’ll experience in the real world before they have been built. This is a design validation tool that helps our engineers to test the designs earlier in the design cycle and against real-world conditions. This lead us to improved design quality and manufacturing efficiency, while reducing time to market, costs and materials waste.