A Gas-Free Tank or Compartment Inspection is a critical safety procedure performed to ensure that enclosed spaces on a vessel are free from hazardous gases before entry, maintenance, or repair work. Using advanced technology, such as the ALTAIR 5X multi-gas detector, a qualified Marine Surveyor can accurately detect flammable, toxic, or oxygen-deficient atmospheres, helping protect personnel and prevent accidents.
Enclosed tanks, fuel compartments, and bilges can accumulate flammable vapors, toxic gases, or low-oxygen conditions over time. A Gas-Free Inspection is essential for:

  • Routine maintenance or repair work in enclosed spaces
  • Pre-purchase evaluations to verify safe operating conditions
  • Insurance or regulatory compliance requirements
  • Owner or crew safety during fuel or storage tank access

During a Gas-Free Tank or Compartment Inspection, the surveyor:

  1. Uses an ALTAIR 5X multi-gas detector to measure levels of:
    o Flammable gases (LEL / Upper Explosion Limit), Oxygen content, Carbon monoxide and other toxic gases, Hydrogen Sulfide, Chlorine, Ammonia, Nitrogen and more.
  2. Systematically tests all enclosed compartments, including fuel tanks, voids, bilges, and storage areas
  3. Documents readings and identify any areas of concern
  4. Provides a formal inspection report confirming the spaces are safe for personnel entry or work This inspection is non-invasive, fast, and highly accurate, ensuring reliable results without disrupting
    vessel operations.