Expansion joints

Expansion joints are devices containing a bellows membrane that are designed to absorb dimensional changes, such as those that occur due to thermal expansion or contraction of a pipeline, duct or vessel.

Piping Expansion Joint Construction

Pipe expansion joints are also known as compensators, as they 'compensate' for the thermal movement.

Piping Expansion Joint Construction
Expansion joint accessories
  1. Bellows
  2. Angle Flange
  3. Weld End
  4. Liner (Baffle)
  5. Cover
  6. Particulate
  7. Barrier/Insulation
  8. Liner Seal
  9. Purge

Expansion joint accessories

What industries use expansion joints?

Expansion joints are used in all kinds of different sectors and in a huge range of different industrial contexts. Essentially, wherever there is a need to control pipework movement expansion joints are required.







Thick Wall Pipe Expansion Joint

Thick Wall expansion joints are frequently used in heat exchangers, furnace and blast furnace pipe work.

Thick Wall Pipe Expansion Joint

Thick Wall Pipe Expansion Joint

These may be a cost-effective option for large-diameter piping systems which operate at low pressure. Metals can be selected to satisfy different temperature conditions. The distribution of axial, angular, and lateral forces will be different when thick-wall pipe expansion joints are used. We can provide your design engineers with the potential forces and movements for proper design of the structural members supporting the system. These joints have a long life which justifies the initial investment.

Thick-wall expansion joints are used primarily in heat exchangers and large diameter piping systems where thin-wall expansion joints would not be sufficient. The bellows are typically fabricated from A516 Grade 70 material, with the thickness ranging from 3/16" to 1". Other materials are available to meet different temperature requirements.

Thick Wall Expansion Joints are normally supplied without any end connections due to the fact that it is easier to weld the end fittings to them by a relatively less skilled welders. The heavy wall bellows are less susceptible to damage during installation and system start-up however these bellows possess high spring forces as a result of high convolution profile. The thickness of these thick wall bellows elements vary from 1 mm to 3 mm depending up on size and the height of convolution varies from 50 mm to 100 mm.

Thick Wall Expansion Joint (Bellows), has a very diverse methodology, which is explained in one of the articles below. The following calculations are supported:

  • Cylinder calculations
  • Differential axial thermal expansion
  • Axial rigidity
  • Radii requirements
  • Cylinder calculations
  • Cycle life
  • Minimum thickness based on material and service
Universal tied expansion joint

Universal tied expansion joints consist of two bellows with a central pipe and tie rods to withstand reaction forces produced by internal pressure.  The universal tied expansion joint allows large lateral movement in all planes, this movement can be increased by increasing the length of the central pipe. 

universal tied expansion joint with flanges

Universal tied expansion joint with flanges

The universal tied expansion joint can take greater axial, lateral and angular movements than a single tied expansion joint. If the universal tied expansion joint is designed with only two tie rods, equally spaced @ 180 degree, the expansion joint will take both lateral and angular movements. If more than two tie rods are used then this kind of expansion joint will only take lateral movement. Dome washers are also used depending upon the design requirement.

Universal tied expansion joint with pipe ends

Universal tied expansion joint with pipe ends

Keywards:Universal tied expansion joint, Universal expansion joint, Universal tied expansion joint with flanges, Universal tied expansion joint with pipe ends

Fitting specification, Standard and identification

There are different varieties of pipe fittings made of various materials and available in various shapes and sizes.