Fire extinguishing system

• US 4,289,207 A
• Filed: 02/05/1979
• Issued: 09/15/1981
• Est. Priority Date: 02/05/1979
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Americas Company (Caterpillar Incorporated)
• Inventors: Wernert, Gregory M.
• Primary Examiner(s): Spar, Robert J.
• Assistant Examiner(s): NOLAND, KENNETH W
• Application Number:
  US06/008,981
• Time in Patent Office: 953 Days
• Field of Search: 169/30, 169/71, 169/9, 73/716, 73/736, 73/708, 116/70, 116/216, 239/71, 239/74
• US Class Current: 169/30
• CPC Class Codes: A62C 37/50 Testing or indicating devices for determining the state of readiness of the equipment

Abstract

In a fire extinguishing system including a pressure vessel (10) filled with a non-solid fire extinguishing material (12) having a vapor pressure that fluctuates with temperature, a controllable outlet (14, 16, 18) for the vessel, and a pressure sensing device (20) for monitoring the pressure in the vessel, the improvement wherein the pressure sensing device includes a differential pressure sensing device (20) having two input ports (22, 24) one of the ports (22) being in fluid communication with the interior or the pressure vessel, and a sealed second vessel (26) in sufficiently close proximity to the pressure vessel so as to be exposed to the same ambient temperature as the pressure vessel and filled with fire extinguishing material (28) substantially to a desired fill density, the other of the ports (24) being in communication with the interior of the second vessel (26). The system is self compensating for widely varying temperatures which affect the pressures exerted by the fire extinguishing material (12, 28) so that an accurate indication of the charged condition of the extinguisher is provided regardless of temperature.

Claims

1. In a fire extinguishing system including a pressure vessel (10) filled to a desired fill density with a non-solid fire extinguishing material (12) having a vapor pressure that fluctuates with temperature, a controllable outlet (14,16,18) from said vessel, and a pressure sensing device (20) for monitoring the pressure in said vessel, the improvement wherein said pressure sensing device includes a differential pressure sensing device (20) having two input ports (22,24), one (22) of said ports being in fluid communication with the interior of said pressure vessel, and a sealed second vessel (26) in sufficiently close proximity to said pressure vessel so as to be exposed to the same ambient temperatures as the pressure vessel and filled with said fire extinguishing material (28) substantially to said desired fill density, the other (24) of said ports being in fluid communication with the interior of said second vessel.

2. The fire extinguishing system of claim 1 wherein said second vessel is located within said pressure vessel.

3. The fire extinguishing system of claim 1 wherein said second vessel is located within said pressure vessel so as to be in direct heat transfer relation to fire extinguishing material received in said pressure vessel.