FTF - Twin Sphere


A flexible joint made of heat resisting synthetic elastomers and moulded in a twin sphere shape with vanstoned metal floating flanges, pipe unions or threaded mating flanges.

Ideal for applications requiring large axial, lateral and angular movements. Industries include shipbuilding, power generation, chemical plants and buildings.

Style FTF joints are not capable of absorbing more than one movement at a time (i.e. non-concurrent), nor absorbing torsional (i.e twisting) movement.

Manufactured from heat and chemical resisting elastomers of special composition superior to natural or chloroprene rubber, reinforced with tough nylon fibre cord. The moulded vanstone flange has imbedded in its wall a high tensile wire to ensure rigidity. A heavy duty expansion joint is available for pressures up to 2300kpa (335psi) which has a reinforcing ring attached on the outside of the joint between the twin spheres.

These joints are fitted with metal floating flanges drilled to ANSI, BS Tables, JIS and DIN. The most common drillings are ANSI 150, BS Table E and DIN 16.

Note: the flange thicknesses are all basically the same and are not necessarily in accordance with the relevant flange standard.

The standard joint is fitted with plated carbon steel flanges. Hot dip galvanised and stainless steel flanges are also available on special order.

The moulded spherical rubber expansion joints are available in three ranges of lengths. These three ranges are identified as styles FTF, FTFA and FTFB as per the attached specifications.


Nominal Bore
32 - 750mm

Material Types
Various Types Available

Positive Pressure
758 - 1600 kPa

Negative Pressure
600 mm H.g