Inert gas system test

An inert gas system test verifies that a tanker’s IG plant can deliver gas to the cargo tanks at the required oxygen content and pressure to keep the atmosphere outside the flammable range. SOLAS II-2 Reg. 4 caps delivered gas oxygen at 5 percent by volume and requires tank atmospheres held at or below 8 percent oxygen with a positive deck pressure. The trial checks the scrubber, blowers, deck water seal, pressure-vacuum breaker, non-return arrangements, oxygen analyzers, and the low-pressure and high-oxygen alarms and trips. It is witnessed at new construction, at the gas trial, and at periodic surveys. A system that cannot hold oxygen below the limit cannot load.