§ 154.808 - Vapor control system, general.

(a) A vapor control system design and installation must eliminate potential overfill hazards, overpressure and vacuum hazards, and sources of ignition to the maximum practical extent. Each remaining hazard source which is not eliminated must be specifically addressed in the protection system design and operational requirements.

(b) Vapor collection system piping and fittings must be in accordance with ANSI B31.3 (incorporated by reference; see §154.106) and designed for a maximum allowable working pressure of at least 150 psig. Valves and flanges must be in accordance with ANSI B16.5 or B16.24 (both incorporated by reference; see §154.106), 150 pound class.

(c) All electrical equipment used in a vapor control system must comply with NFPA 70.

(d) Any pressure, flow, or concentration indication required by this part must provide a remote indicator on the facility where the cargo transfer and vapor control systems are controlled.

(e) Any alarm condition specified in this part must activate an audible and visible alarm where the cargo transfer and vapor control systems are controlled.

(f) The vapor control system must be separated or insulated from external heat sources to limit vapor control system piping surface temperature to not more than 177 °C. (350 °F.) during normal operation.

(g) A means must be provided to eliminate any liquid condensate from the vapor collection system which carries over from the vessel or condenses as a result of an enrichment process.

(h) If a liquid knockout vessel is installed it must have:

(1) A means to indicate the level of liquid in the device;

(2) A high liquid level sensor that activates an alarm; and

(3) A high high level sensor that closes the remotely operated cargo vapor shutoff valve required by §154.810(a) of this subpart and shuts down any compressors or blowers prior to liquid carrying over from the vessel to the compressor or blower.

(i) Vapor collection piping must be electrically grounded and electrically continuous.

(j) If the facility handles inerted vapors of cargoes containing sulfur, provisions must be made to control heating from pyrophoric iron sulfide deposits in the vapor collection line.

[CGD 88–102, 55 FR 25429, June 21, 1990, as amended by USCG–2001–8661, 74 FR 45023, Aug. 31, 2009]