# Vapor-moving devices.

**Citation:** 33 CFR 154.2108  
**Type / status:** regulation / current  
**Agency:** United States Coast Guard  
**Effective:** 2026-08-18  
**Published:** Not stated

(a) Paragraphs (b) and (e) of this section apply only to facilities collecting vapors of flammable, combustible, or non-high flash point liquid cargoes.

(b) Each inlet and outlet to a vapor-moving device that handles vapor that has not been inerted, enriched, or diluted in accordance with 33 CFR 15

## Document text

(a) Paragraphs (b) and (e) of this section apply only to facilities collecting vapors of flammable, combustible, or non-high flash point liquid cargoes.

(b) Each inlet and outlet to a vapor-moving device that handles vapor that has not been inerted, enriched, or diluted in accordance with 33 CFR 154.2107 must be fitted with a detonation arrester; however, the outlet detonation arrester may be omitted if the vapor-moving device is within 50 times the pipe's diameter of the detonation arrester required by 33 CFR 154.2109(a).

(c) If the vapor is handled by a reciprocating or screw-type compressor in the vapor collection system, the compressor must be installed with indicators and audible and visible alarms to warn against the following conditions:

(1) Excessive gas temperature at the compressor outlet;

(2) Excessive cooling water temperature;

(3) Excessive vibration;

(4) Low lube oil level;

(5) Low lube oil pressure; and

(6) Excessive shaft bearing temperature.

(d) If the vapor is handled by a liquid ring-type compressor in the vapor collection system, it must be installed with indicators and audible and visible alarms to warn against the following conditions:

(1) Low level of liquid sealing medium;

(2) Lack of flow of the liquid sealing medium;

(3) Excessive temperature of the liquid sealing medium;

(4) Low lube oil level;

(5) Low lube oil pressure, if pressurized lubricating system; and

(6) Excessive shaft bearing temperature.

(e) If the vapor is handled by a centrifugal compressor, fan, or lobe blower in the vapor collection system, construction of the blades or housing must be one of the following:

(1) Blades or housing of nonmetallic construction;

(2) Blades and housing of nonferrous material;

(3) Blades and housing of corrosion resistant steel;

(4) Ferrous blades and housing with one-half inch or more design tip clearance;

(5) Nonferrous blades and ferrous housing with one-half inch or more design tip clearance; or

(6) Blades of aluminum or magnesium alloy and a ferrous housing with a nonferrous insert sleeve at the periphery of the impeller.

## Provenance

- Official: Yes
- Source: <https://www.ecfr.gov/on/2026-08-18/title-33/section-154.2108>
- Source ID: `ecfr`
- SHA-256: `61e41cf13cc04b78f01aa6b183b3e235756b984e9c42184f6e39edeb1964fbe8`
- Retrieved: 2026-08-20T06:28:21.529Z
- Exported: 2026-08-23T19:19:01.130Z
- Document slug: `33-cfr-154-2108`

### Source metadata

```json
{
  "cfrTitle": 33,
  "part": "154",
  "section": "154.2108",
  "subpart": "Subpart P—Marine Vapor Control Systems",
  "corpusVersion": "2026-08-18",
  "jurisdiction": "US"
}
```