Nitrogen Inert Gas System
A lot of cargoes carried by chemical tankers need to be transported under a protective nitrogen padding to prevent the chemicals from reacting with the oxygen or moisture in the air, to ensure the quality of the cargo as well as act as an inert gas, preventing possible ignition and fire. This nitrogen padding is to be maintained automatically at a pressure above 0.07 bar at all time below the opening pressure of the pressure/vacuum valves which typically is 0.21 bar.
The Safetec Nitrogen Inert Gas System is designed to give a high capacity nitrogen flow >100 Nm3/h at 7-10 bar pressure for purging of cargo lines and cargo pumps.
At each connection to the cargo tanks and to the cargo handling system, a shut-down valve and a low pressure non-return valve with a flexible connection will give the required cargo segregation.
If nothing is specified, total nitrogen volume to be available on board will typically be 2-5% of total cargo volume. As a minimum, providing gas tight cargo tanks with no leakage, the Nitrogen Inert Gas System is to maintain the required pressure in the tanks under changing atmospheric condition.
Safetec membrane nitrogen generator can substitute a cylinder system. Typically a 2-3 m3 10 bar tank will provide back-up nitrogen for padding and makes the ship independent of nitrogen supply for shore. When used together with a high pressure booster compressor, this can provide nitrogen for accumulation in a high pressure nitrogen cylinder system.
Download Nitrogen Inert Gas System Brochure