Evaluation of Ultra High Pressure (UHP) Firefighting in a Room-and-Contents Fire
Abstract
For aircraft rescue firefighting response USAF uses a fleet of ultrahigh-pressure (UHP) (> 1,100 psi) fire trucks that are effective in extinguishing Class B fuel fires. As most fires extinguished by USAF firefighters involve structures, this study evaluated UHP technology responding to a room-and-contents structural fire. 3 response components were evaluated: extinguishment performance, hydraulic ventilation, and effort to deploy fire hoses. 30 fire tests were conducted in a 12-by-18-ft (3.66-by-5.49-m) burn room furnished to simulate a typical kitchen. Flashover fires were attacked using 15 and 20 gpm at both UHP and low pressure (LP) (90~110 psi) and using 100 gpm LP. All fires were extinguished. At 15 and 20 gpm UHP and LP consumed similar volumes of water; more water was required at 100 gpm. At equivalent flow rates, UHP cooled the burn room faster than LP. Cooling was fastest at 100 gpm delivery. Hydraulic ventilation properties were tested in a separate room with a 2- x 3-ft window opening. Each of 5 firefighting nozzles tested was installed perpendicular to the center of the window at several distances; a range of fog patterns was tested. Hydraulic ventilation was measured using an orifice flowmeter. LP, low-flow rate delivery provided less ventilation than UHP at the same water flow rate; 20 gpm UHP delivery caused the greatest airflow and 100-gpm LP produced nearly the same airflow. Hose pull force was measured by attaching fire hoses to a load cell and pulling them at 3 mph over gravel, asphalt and grass. On grass, the hose was also pulled around a vertical 4-in pipe. On all surfaces tested, pulling the LP hose required less force empty, but more force filled and pressurized than the LP hose.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 15, 2017
- Accession Number
- AD1049376
Entities
People
- Michael J. Mcdonald