46 CFR § 76.33-10 - Location and spacing of accumulators.
(a) Smoke accumulators must be located overhead in each compartment. Where liable to physical damage, the accumulators and piping must be suitably protected.
(b) No spot on the overhead of a protected space may be more than 40 feet from an accumulator.
(c) Accumulators must not be located closer to the opening of a ventilator than three times the diameter or equivalent diameter of the opening.