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maritime DC & PPE Information Center


Heptafluoropropane (HFP) System


HFP is the Navy's term for a specific gaseous fire extinguishing agent which is an alternative to Halon 1301 in some new ships. The HFP chemical is a compound of carbon, fluorine and hydrogen in the formula C3F7H. It is also known commercially as HFC-227ea and by the proprietary trade names FE-227 (E.I. Du Pont De Nemours & Co) and Firemaster 200 (or FM-200, Great Lakes Chemical Co.). HFP is a colorless, odorless and electrically non-conducting gas. HFP is clean and leaves no residue. On Navy ships, HFP is stored in steel containers at 600 PSIG at 70°F (41 bars at 21°C), as a liquified compressed gas, with nitrogen added to improve the discharge characteristics. When discharged, HFP liquid vaporizes into a gas at the discharge nozzle and is uniformly distributed as it enters the fire space. HFP replaces Halon 1301 in some limited new ship design applications, such as fuel pump rooms and flammable liquid storerooms in CVN-76 and engine enclosures and flammable liquid storerooms in the LPD-17 Class. The new installation of Halon 1301 is restricted by international treaty because it depletes ozone. Halon 1301 will continue to be supported in existing ship classes, including new construction of the DDG-51 class.

HFP extinguishes fire with a combination of physical and chemical mechanisms. Unlike Halon 1301, HFP extinguishes primarily by physical mechanisms.



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