StacksVerified U.S. regulatory reference

33 CFR §154.2108

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Paragraphs (b) and (e) of this section apply only to facilities collecting vapors of flammable, combustible, or non-high flash point liquid cargoes.
  2. (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).
  3. (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. (1)Excessive gas temperature at the compressor outlet;
    2. (2)Excessive cooling water temperature;
    3. (3)Excessive vibration;
    4. (4)Low lube oil level;
    5. (5)Low lube oil pressure; and
    6. (6)Excessive shaft bearing temperature.
  4. (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. (1)Low level of liquid sealing medium;
    2. (2)Lack of flow of the liquid sealing medium;
    3. (3)Excessive temperature of the liquid sealing medium;
    4. (4)Low lube oil level;
    5. (5)Low lube oil pressure, if pressurized lubricating system; and
    6. (6)Excessive shaft bearing temperature.
  5. (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. (1)Blades or housing of nonmetallic construction;
    2. (2)Blades and housing of nonferrous material;
    3. (3)Blades and housing of corrosion resistant steel;
    4. (4)Ferrous blades and housing with one-half inch or more design tip clearance;
    5. (5)Nonferrous blades and ferrous housing with one-half inch or more design tip clearance; or
    6. (6)Blades of aluminum or magnesium alloy and a ferrous housing with a nonferrous insert sleeve at the periphery of the impeller.