Hydro-pneumatic Fenders make contact with vessels as submarines below the water line. Hydro-pneumatic fenders can also be used for vessel-to-vessel. Fenders are partially filled with water and ballasted to float vertically. Performance can be tuned by changing the water-to-air ratio and initial pressure. The hydro-pneumatic fender is customized for each type or class of submarine, depending on its water-air ratio, hull shape, berthing type, energy absorption, and jetty design. Therefore, it is strongly advised that a detailed study be carried out for each case.
Features
Robust Construction: Puncture-resistant materials for harsh environments
Modular Installation: Upper/lower flange openings for water cycling
Fail-Safe Design: Pressure relief valve prevents overcompression
Applications
Military: Naval submarines, semi-submersible platforms
Commercial: High-speed ferries, offshore rigs
Specification of Hydro Pneumatic Fenders
| Model | Air filled (no water) | Partially water filled |
| Water: Air | Energy (kNm) | Reaction (kN) | Water: Air | Energy (kNm) | Reaction (kN) |
| HPF 1700x7200 | 0:100 | 566 | 1774 | 65:35 | 135 | 599 |
| HPF 2000x6000 | 0:100 | 653 | 1731 | 65:35 | 157 | 587 |
| HPF 2500x5500 | 0:100 | 937 | 1996 | 65:35 | 225 | 673 |
| HPF 3300x6500 | 0:100 | 1932 | 3106 | 65:35 | 622 | 1222 |
| HPF 3300x10500 | 0:100 | 3151 | 5067 | 65:35 | 595 | 1250 |
The factors as vessel hull shape, water to air ratio, gas mixture (ie. N2) as well as the initial pressure influ the performances of Hydro Pneumatic Fenders. Performances are given for an initial pressure of 7.1 psi and are indicative only.
Installation of Hydro-Pneumatic Fenders
Openings at the upper and lower flanges allow water to charge and discharge. A pressure relief valve allows the controlled release of air in the event of overcompression.