Section 154.904 - Inert gas system: ControlsThe inert gas system must have:
(a) At least one check valve in the cargo area to prevent the back flow of cargo vapor into the inert gas system, or another means specially approved by the Commandant (CG-OES);(b) If the inert gas system is in the machinery space or another space outside the cargo area, a second check valve in the cargo area meeting paragraph (a) of this section;(c) Automatic and manual inert gas pressure controls; and(d) Valves to isolate each inerted space.CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983