Rectagular Metal Expansion Joints & Bellows

                  In Pipeline systems, such as the ones in Pharmaceutical, Chemical, Power, Glass, Petrochemicals, Oil and Gas, and Steel Industries, expansion and contraction of metal takes place, with variations in temperature. With this expansion and contraction of metal, there is variations in movement of the individual sections of the pipes.
                  If the movement cannot be absorbed by the piping system, then metal expansion joints are used to compensate the movements that occur. Apart from the thermal movement, other applications such as vibrations and noise in pumps, compensator, turbines, motors and vessels is also compensated by using metal expansion joints.
                  Depending upon the nature of movement that needs to be compensated ( axial, lateral or angular ), expansion joints are designed. Ocelflex’s Metal Expansion Joints are designed to absorb the movement, as well as withstand other operating conditions such as ,i>temperature, pressure and the inner media. Our design is in accordance with international standards such as E.J.M.A. and A.S.M.E..
Single Rectangular Metal Expansion Joint
                  Single Rectangular Expansion Joints consists of a single rectangular metallic bellow welded to end connections. Normally, the expansion bellow is capable to absorb – axial, lateral and angular movements.

                  Since it is capable of carrying all the three movements, the connected piping system must be guided so as to allow the movement to occur without causing any damage. A single rectangular expansion joint is capable of carrying more axial compression and extension, and small amounts of angular and lateral movements.

                  This simple rectangular metal expansion joint, is used in applications which require minor movements, such as vibrations or thermal fluctuations, applications such as in pumps and compressors, boilers, engines and pressure vessels. Its designs and parameters are similar to the design of a circular expansion joints.

                  Optional Stainless Steel Covers or Inner Sleeve ( Inner Liners ) are available on request. It is recommended to use inner sleeve in applications where there are high frequency vibrations caused by the inner media flow or where the inner media is corrosive enough to damage the inner thin wall of the metal expansion bellow.

                  Metal Expansion Joints are available as tied or untied type. In case of Tied Rectangular Expansion Joints, the end connections is welded to tie rods using lugs, which are capable to carry the pressure thrust of the system, to provide protection in case of failure in the main anchors.

  • ⇨ Bellow Inner Diameter : DN 40 to DN 5000 ( 40 NB to 5000 NB, 40 mm to 5 mtrs)
  • ⇨ Bellow Length : 4" to 18" Long ( 100 mm to 450 mm ). Also available as per your specification
  • ⇨ Design Standard : Bellow : E.J.M.A. 9, A.S.M.E., End Fittings : Custom Made or Standardized
  • ⇨ Pressure & Temperature : Temperature : upto 700 C, Pressure : upto 30 Kg/cm2
  • ⇨ Additional Accessories : Lugs and Tied Rods, Inner Sleeve, External Protective Cover
  • ⇨ Bellow Material : Stainless Steel 300 Class ( AISI 304, AISI 316, AISI 321, AISI 316L, AISI 304L), Inconel.
  • ⇨ Inspection Documentation : Leakage Test Reports, Specification Inspection Report, Material Test Report.
Material & Standard
Fill Specification Sheet
Technical Details
Universal Rectangular Metal Expansion Joint
                  Universal Rectangular Metal Expansion Joint is two single expansion bellows being connected by a rectangular centre piece. Also known as Lateral Rectangular Expansion Joints, since such a metal expansion bellow is more capable of absorbing lateral movement and angular movement, as compared to axial movement. The centre piece of the Universal Rectangular Expansion joint should not be anchored, since it is responsible to provide the movement when required by the piping system.

                  Many variations are possible while designing the tie rod of the Universal Expansion Joint. A single long tie rod can be used in sets, joining both the expansion bellows of the universal expansion joint. Other way of designing a universal rectangular expansion joint is using sets of tie rods per metallic expansion bellow, thus allowing greater lateral movement to take place.

                  For Circular Expansion Joints, the pressure stress is equivalent to circumferential membrane stress, where as for the Rectangular expansion joints, the longitudinal bending stress is calculated.

Designs for Rectangular Metal Expansion Joint







Rectangular Expansion Joints with

U Type Convolutions

Rectangular Expansion Joints with

V Type Convolutions

Types of Metal Expansion Joints / Expansion Bellows

                   Depending upon the nature of movement, and upon the piping system where the expansion joint has to be installed, there are different types of Metal Expansion Joints. Review the metal expansion joints below to choose the optimal design for your applications. Click on any to understand how the expansion joint works :

Understanding Expansion Joints Terminology & Definitions
                   Many parameters are to be considered to design an expansion joint. To understand these and other expansion joint terminology, refer the below links.
                   Depending upon your application and requirement, you can fill out the metal expansion joint specification sheet for us to understand your enquiry, and based on our experience we shall quote the most suitable metal expansion joint for your application, at the most competitive rates. In case you already have a sample, and would like us to manufacture a similar product, then you can send us the photographs, dimensions and/or drawings.

  • Expansion Bellows, Expansion Joints, Pressure & Temperature Parameters
  • Inner Sleeve, Multi Ply, No. of Convolutions, Material of Construction
  • Axial, Lateral and Angular Movement
  • Pipe Guides and Anchoring, End Fittings / Connections & Standards
  • E.J.M.A. standard and other designs