A Twin Sphere Joint, sometimes referred to as a Twin Sphere Rubber Expansion Joint, is a flexible connector designed with two spherical bellows to absorb movement, vibration, and noise in piping systems.
The FTC type generally indicates a Flanged Type Connector, where the rubber body is fitted with integral or floating flanges for secure installation.
Body
Material: Reinforced synthetic rubber such as EPDM, NBR, or Neoprene (depending on media).
Design: Two spherical bellows increase flexibility and movement absorption.
Reinforcement
Multiple plies of high-strength synthetic fabric, sometimes combined with steel wire reinforcement for higher pressure.
End Fittings
FTC Type: Flanged connections, either fixed or floating, in carbon steel, stainless steel, or ductile iron.
Flanges drilled to standards such as ANSI, JIS, DIN, or BS.
Inner Liner
Rubber grade selected to resist specific media (water, oil, chemicals, etc.).
Size Range: DN25 (1") to DN1200 (48") or larger.
Working Pressure: 10 bar (PN10) standard, higher ratings available on request.
Vacuum Resistance: Up to –650 mmHg with internal vacuum support.
Temperature Range: –20 °C to +100 °C (depending on rubber compound).
Movement Capability:
Axial Compression: ~20–30 mm
Axial Elongation: ~10–15 mm
Lateral Deflection: ~15–20 mm
Angular Deflection: up to 15°
HVAC Systems – vibration isolation for pumps, chillers, and cooling towers.
Water & Wastewater – flexible connections for pipelines in treatment plants.
Industrial Piping – chemical plants, oil refineries, and power stations.
Marine & Offshore – seawater and ballast water systems.
Pumps & Compressors – absorb pulsations and reduce stress on equipment.
Twin sphere design provides greater movement absorption than single sphere joints.
Noise & vibration reduction improves system performance.
Corrosion-resistant construction with suitable flange and rubber material selection.
Long service life under dynamic conditions.
Easy installation with standard flanged ends.
