Expansion-joint sealing cushions (valve) for refurbishing bridges and tunnels

Cable sealing
(Telecommunication sector)

  • Successfully tested since December 2006!
  • Up to 2015, 50.000 sealing cushions
    installed in Germany, Switzerlan,
    Austria, USA and Japan.
  • Approved by Deutsche Telekom AG
  • Fulfils the technical requirements of
    T-Com TS 0307/96, British Telecom
    LN 584 and France Telecom

Further development
to seal expansion joints

  • Successfully tested since January 2011!
  • Sealing cushion lengths up to 23 m.
  • With several cushions,
    adaptable to over 100 m

    64 units installed for German Rail
    network (DB Netz AG) and 17 units
    for Austrian Rail (ÖBB AG).
    (Status 2015).

Wolf News

  • 09. pilot project
    Installation of expansion joint sealing DB Netz AG Regional areas West/Central. Innovative, economical expansion joint renovation, to prevent damage to people or property.

  • 11. pilot project
    Retro-sealing expansion joints in record time! The large-scale Austrian Rail infrastructure project, begun in June 2009, was completed in only 5 years – and the retro-sealing of a 27 m long expansion joint, the 11th pilot project of Wolf Kabeltechnik, Stuttgart, Germany, was also carried out there in record-breaking time.

  • 12. pilot project:
    Sealing of expansion joints against stone chippings and water flow


Advantages of the system

1. Long service life

due to extremely low diffusion rate, only 2.7 mbarl/ year!

Test result: GEMTEC
Diffusion rate of sealing cushions with a valve end-cap

Sample No. 1:
5,5x10-8 mbarl/sec | = 1,5 mbarl/Year

Sample No. 2:
6,2x10-8 mbarl/sec | = 2,7 mbarl/Year

2. Optimum adaptation
     to joint movement

3. Usable independently
    of the joint type
    straight –angled
    - curved

4. Installation is independent
     of weather or
     ambient temperature




5. Efficient and economical

  • Installation time < 10 min/ m
  • Easy to remove for bridge inspection work
  • Reusable (4 x)
  • Simple tightness monitoring (with protocol)
  • Lightweight:
    Type S approx. 0.74 kg/ m
    Type L approx. 0.32 kg/ m

6. Anwendbar für Fugenbreiten
von 2 bis 16 cm




Function models for real-life conditions

  • Demonstration of sealing techniques
  • For the qualification and further training of construction supervisors and installation staff