Heavy Duty Metal Expansion Joints

ProcessBarron’s metal expansion joints are supplied in round, square, and rectangular configurations to accommodate for axial and lateral movements in flue gas and process duct systems. These joints can be manufactured from various materials to accommodate for more corrosive or high-temperature environments.

To match the specified connecting duct, metal expansion joints are produced with the following options:

  • Standard angle
  • Bar
  • Pip flanges

Additionally, axial, lateral (x and y direction) spring rates, and cycle life data are available for each expansion joint.

Metal Expansion Joint Construction:

Design: Rectangular duct expansion joints are designed in accordance with the Expansion Joint Manufacturers Association (EJMA). This ensures compensation for thermal expansion in duct systems to precipitators, scrubbers, turbines, boiler breeching, and other gas systems.

Pressure: Type A expansion joints are designed for /-100” water gauge pressure, maximum temperature of 1000˚F. Type B expansion joints are designed for service from full vacuum to 15 PSIG at a maximum temperature of 1000˚F.

Movements: ProcessBarron can furnish a design for any combination of axial, lateral, or angular movement per customer specification.

Bellows: Rectangular bellows are die formed from .050″ thick, deep-drawn, quality annealed sheet conforming to ASTM specifications, available in two standard designs.

Liners: Internal liners should be specified when flow velocity exceeds 25 FPS or where abrasive particles in the gas stream could cause erosion of bellows.


  • Single Miter Corner: the most economical design for most applications, available on Type A or B expansion joints
  • Camera Corner: additional flexibility for duct systems that operate under more cyclical conditions, available on Type A expansion joints
  • Round Corner: maximum flexibility and pressure capacity, available on Type B expansion joints