DFS Type
expansion joints

DFS Type <br/>expansion joints
DFS type with tie rods

Item Designation
1 Rubber bellows
2 Flanges
3 Reinforcement ring
4 Loose brackets
5 Tie rods
6 Nuts
7 Spherical washers

DFS Type
expansion joints

Features

  • Transportation or piping systems that carry fluids, slurries or gasses under pressure or vacuum at varying temperatures
  • Reduction of vibration
  • Dampen sound transmission
  • Compensate movements due thermal changes, misalignments caused by wear, load stresses, settling of supporting foundations
  • Molding and manual production.
  • Standard measures (length)

Advantages

  • Easy installation
  • Flanges are not in contact with medium, which enables lower grade material
  • Galvanic surfaces / coatings possible
  • Gaskets can be eliminated
  • Additional movement capabilities
  • Special measures (length, diameter, flanges) → custom made
  • Different models (hose, reduction, multiple arches, filled arch, spool, …)
  • Higher design pressure
  • Special designs (spring rates, different inner and outer layers)

Operating range

Diameter: DN 25 ... DN 3000 (1" ... 120")
Pressure as per request
Temperature up to 180 °C (356 °F)
Movements: all directions

Materials

  • Bellows: Various elastomers such as EPDM, EPDM Food Grade, Neoprene, Nitrile, Hypalon, Butyl, Viton
  • Flanges: carbon steel and stainless steel.

  • Other materials are available on request.

Standards and approvals

NDT and documentation: Can be provided per customer request e.g. Material Certificates and NDT test reports.



Product variants

DFS type double/multiple arch

Higher maximum movements, lower spring rates.
DFS type PTFE liner

High temperatures or chemical attack. Not recommended for negative pressure.

Item Designation
1 Rubber bellows
2 Flanges
3 Reinforcement ring
4 PTFE liner
DFS type reduction (conical)

Connection between different DNs.

Item Designation
1 Rubber bellows
2 Flanges
3 Reinforcement ring
DFS type spool

Installation with clamping bands. Maximum pressure 1 -2 BarG.

Item Designation
1 Rubber bellows
2 Reinforcement ring
DFS type filled arch

To avoid deposits in the arch area. Reduced movements and higher spring rates. Not recommended in case of negative pressure.

Item Designation
1 Rubber bellows
2 Flanges
3 Reinforcement ring
4 Filler
DFS type elbow

With or without arches.

Item Designation
1 Rubber bellows
2 Flanges
DFS type pressure balanced

In line or elbow construction. No transmission of pressure thrust with absorbtion of axial and lateral movements.

Item Designation
1 Rubber bellows
2 Flanges
3 Reinforcement ring
4 Flanges
5 Nuts
6 Rubber bellows
DFS type rectangular

Only for low pressure.

Item Designation
1 Rubber bellows
2 Flanges
DFS type dog bone

On condensers in central power stations.
DFS type wall seal

For axial, angular and lateral movements. Pressures up to 2,5 BarG
DFS type diamantling joints

To allow dismantling of equipment for maintenence purposes.
False