VENT SYSTEM OVERPRESSURIZATION

Venting systems are employed on marine vessels to relieve pressure differences which arise between the cargo tank and the ambient. In the case of closed gauging or a vapor recovery system, there will be a pressure rise in the tank which depends on the cargo pumping rate and the vapor relief capacity of the vent system. If the system does not have the proper capacity or if there is an accidental overfill, tank failure may occur. An analytical study of venting systems was carried out and the results have been confirmed by scale-model experiments. Typical venting systems in use today have more than adequate capacity for gas venting, but inadequate capacity for liquid overfill. Cargo volatility has a relatively small effect on the hazard evaluation. Many cargo transfer operations currently equal or exceed permissible overfill ratios, having ratios of 30 ft/sec and greater. Furthermore, tank failure is expected within a very short time (less than one minute). A method for evaluating overpressure hazard during cargo loading operations is presented.

  • Availability:
  • Supplemental Notes:
    • Paper presented on ASNE Day 1978, May 4-5, 1978, Washington, D.C.
  • Corporate Authors:

    American Society of Naval Engineers

    Suite 507, 1012 14th Street, NW
    Washington, DC  United States  20005
  • Authors:
    • Flessner, M F
  • Publication Date: 1978-2

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00173535
  • Record Type: Publication
  • Source Agency: Naval Engineers Journal
  • Files: TRIS
  • Created Date: Apr 26 1978 12:00AM