---
kind: "section"
citation: "46 C.F.R. § 154.345"
title: "46"
number: "154.345"
heading: "Air locks."
url: "https://uscodex.org/cfr/46/154.345"
---

# §154.345. Air locks.

- (a) An air lock may be used for access from a gas-dangerous zone on the weather deck to a gas-safe space.
- (b) **Each air lock must—**
  - (1) Consist of two steel doors, at least 1.5 m (4.9 ft.) but not more than 2.5 m (8.2 ft.) apart, each gasketed and tight when tested with a fire hose at not less 207 kPa gauge (30 psig);
  - (2) Have self-closing doors with no latches or other devices for holding them open;
  - (3) Have an audible and visual alarm on both sides which are actuated when both door securing devices are in other than the fully closed position at the same time;
  - (4) Have mechanical ventilation in the space between the doors from a gas-safe area;
  - (5) Have a pressure greater than that of the gas-dangerous area on the weather deck;
  - (6) Have the rate of air change in the space between the doors of at least 8 changes per hour; and
  - (7) Have the space between the doors monitored for cargo vapor leaks under [§ 154.1350](/cfr/46/154.1350.md).
- (c) In addition to the requirements of paragraphs [(a)](#a) and [(b)](#b) of this section, no gas-safe space on a liquefied flammable gas carrier may have an air lock unless the space:
  - (1) Is mechanically ventilated to make the pressure in the space greater than that in the air lock; and
  - (2) Has a means of automatically de-energizing all electrical equipment that is not explosion-proof in the space when the pressure in the space falls to or below the pressure in the air lock.

## Notes

### Authority

Authority: 46 U.S.C. 3703, 9101; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted.