Depending on the weight and distribution of the load in the hull, ballast tank systems either flood or empty the distributed tanks. This “trimming” generates counterweights on demand, keeping the ship stable on water. The special challenge: “The system has to continue functioning even in the event of power failure and if the valves are completely submerged,” said Abdullah Özer, product manager responsible for ballast tank systems. To address this, Aventics has equipped ships and offshore facilities with automation solutions and ship controls from the Marex family. The Marex Valve Control System (VCS) ballast tank system has proven itself to be extremely reliable.
Previously, hydraulic systems were often used, but shipyards wanted to reduce tubing effort, system costs and increase environmental friendliness. Here, pneumatics shows its strengths. Pneumatic tubing and components are significantly less expensive than hydraulic lines. Furthermore, installation is substantially easier because the pressure reaches a maximum of 7 bars. Additionally, the crew can easily service pneumatic systems on the high seas with tools on board.
The pneumatic actuators of the Marex VCS can be mounted in the tanks and adjust the valves on the ballast tanks without electricity. Pneumatic transmission prevents short circuits in the ballast tanks. An active pneumatic position display, the feedback line, sends the current valve position to the controller without current, ensuring reliable monitoring.
Depending on the size of the ship, Marex VCS controls pneumatic switching for up to 100 ballast and quick release valves, including air preparation and all necessary operating and control modules. The standard working pressure is 5 to 7 bars. In the event of a power failure, the crew generates the working pressure through one or more manual pumps, maintaining system function.
The ballast tank system can be controlled using the Marex AMC operating and control modules. This automation system is widespread in shipping and allows structured access to all ballast tank system information and functions. Furthermore, it groups and visualizes further systems, such as the engine and reversing gear system. The modular system communicates with the ballast tank system through CAN bus.
It features a self-explanatory touch-screen controller that mimics the ship’s movements and simplifies operation, a major demand in shipping.
If the main system fails, the valves can be controlled through a backup control and a backup system located outside the engine control room. This includes one or more manual pumps that ensure function in the event of a power outage.
These purely pneumatic actuators function in a range of environments: ballast, bilge and HFO (heavy fuel oil) tanks. For all ships and installations in explosive areas—for example, floating oil and gas platforms—the system solution meets ATEX explosion protection requirements.
Aventics
www.aventics.com
Filed Under: Actuators, Pneumatic Tips