The world‘s first fireproof bulkhead seal for drive shafts on commercial, sea-going ships, mega yachts and so-called special craft has come from ProfiSeal. The innovation, which has been registered for patenting, has now received type approval from DNV GL. After a successful water pressure test, the special seal also demonstrated its resistance to fire (A60) over 60 minutes at 945 degrees Celsius.

Despite strict fire protection regulations, opposite to rigid pipe and cable ducts there has hitherto been no structural solution for dynamic components such as rotating shafts, which can give all round satisfaction from an engineering perspective. Profiseal made the breakthrough with a triple arrangement of sealing rings.

So far the proven dry-running, completely split gap seals for shafts from 50 to 400 millimeters in diameter, with two rings, located behind one another, with an allowed radial movement of ± 5 mm, hitherto minimized any water leaks. In the event of a fire, the third, outer ring has now been “sacrificed”. With this quasi-controlled combustion, carbon dioxide is released, which protects both sealing rings to the rear, because the necessary oxygen for combustion is denied.

ProfiSeal also provides highly reliable, type approved propeller shaft seals for new builds and refits. For special projects, the seals are additionally approved through US Coast Guard or Korean Register of Shipping.