Expansion Joints And Bellows

Neeta Bellows specializes in a series of Expansion Joints And Bellows. These are made in our factory located in Mumbai, Maharashtra (India). 

Expansion Joints

The expansion joints find use in piping systems for absorbing terminal movement or thermal expansion wherein it is not possible or not recommended to use 'expansion loops'. We offer these in various different material and shapes. Metals and Rubber are two most common material of construction for these joints. With these products, a series of problems can be solved such as Abrasion, Corrosion, Equipment Movement, Load Stress, Noise, Pressure Pulsation, Shock, Stresses and Vibration.

Metallic Expansion Joints are common in duct systems and pipe work for the prevention of damage cause due to pressure thrust, thermal growth, vibration and other mechanical forces. Stainless steel and top grade nickel alloy steel are most common material used for making these products. Their application areas are in petroleum refineries.

Rubber Expansion Joints are made from synthetic or natural elastomer and fabrics. These are flexible connectors, designed to ease the stress effect in piping systems, which occurs due to thermal changes. The product perfectly compensates for torsional, lateral & angular movements, which helps in evading damage as well as undue downtime of the plant's operation.

Expansion Bellows

These can be made of cascaded capsules and are used for pressure measurement. The most standard method of processing expansion bellows is by fastening the single diaphragms together. The product has a number of convolutions or fold and possess the properties of being axially flexible, collapsible and expansible. Single piece of thin metal can be used to create bellows. 

General processing methods

The expansion bellows can be made by:

  • Forming a drawn tubing, hydraulically
  • Rolling a tube
  • Turning from a solid stock of metal
  • Welding or soldering stamped annular rings


Operating Principle of Expansion Bellows

The elastic parts are operated by the action of tension and bending. In an ideal working condition, tension should have least percentage. The main two factors that define this product are maximum allowable pressure and maximum stroke. By increasing diameter, the force obtained can be enhanced. For increasing the stroke length, the number of folds or convolutions can be increased. Material of construction of these products depends on the following parameters:

  • Corrosion
  • Fabrication ease
  • Fatigue on dynamic operation
  • Hysteresis
  • Range of pressure
  • Sensitivity to fluctuating pressures

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