33 CFR 154.2108
Vapor-moving devices.
(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.#