FIRE FOAM SPECIFICATIONS
Standards for the Installation of Automatic Fire Foam Extinguishing Systems—First Issued in the
The specifications which follow, issued by the Central Actuarial’ Bureau of Chicago, I11., of 175 West Jackson Boulevard, of which C. C. Taylor is manager and J. H. Brumbaugh is chief engineer, are said to be the first ever issued in the United States for the installation of automatic foam fire extinguishing systems. In reffering to the matter, Mr. Brumbaugh writes FIRE AND WATER ENGINEERING: “Some recent severe losses on account of dip tanks seemed to indicate that there was a necessity for specifications of this kind if losses resulting from dip tank hazards and fires originating in other inflammable liquids were to be minimized.”
These specifications, according to Mr. Brumbaugh, were adopted under his direction at a conference of insurance representatives and others interested in the industry. The specifications follow:
Tentative Standard for Automatic Foam Sprinkler Systems. February 28, 1921
This standard relates to a class of automatic fire extinguishing systems designed to discharge, a fire-smothering foam upon fires, particularly those fires which cannot be readily extinguished by water, as for example, fire occurring in inflammable liquids and similar materials.
Section 1. The Foam
- The foam-producing liquids must be such, as will not deteriorate rapidly or become foul, and such as will produce a foam having the following characteristics:
- The foam must be a mass of minute, tough, longlasting bubbles, not easily broken down by vigorous agitation or intense heat, floating on liquid surfaces and adhering to solid surfaces, vertical as well as horizontal, and of such a nature as to resist being easily carried away by ordinary draughts; and not harmful to persons or merchandise.
Section 2. Source of Supply
- The source of supply may orginate in gravity tanks, pressure tanks, or pumps.
- The rate of discharge shall be such as to produce not less than 17 cu. ft. of foam per minute per 100 sq. ft.
- Where ceillings are to be protected, maximum area per sprinkler shall not exceed 64 sq. ft. and nozzle pressure shall be ample to cover this area properly.
- The supply of foam-producing liquids should be sufficient to cover the area protected in any one fire section with a gravity deposit blanket of foam of an average depth of not less than 6 inches.
- Provision should be made for maintaining the supply of liquids at a temperature not less than 50 degrees F. and not more than 100 degrees F. and means provided where necessary for occasional slight agitation of the liquids so as to insure uniform solution.
- All supply tanks and pumps shall be constructed in a manner fully equivalent to standard approved practices so far as they apply.
- The compressed air capacity of pressure tanks must be at least one-half of the liquid capacity. The tanks should be so located as to meet the requirements for sprinkler discharge with a pressure not in excess of 150 lbs.
- One or more extra charges of chemicals shall be kept on hand at all times and facilities separate from the storage tanks shall be provided for mixing the solutions so that the system may be restored to normal operating condition with the least possible delay.
Section 3. Sprinklers
- Foam should be applied through specially designed Foam-type sprinklers, automatic or open, as circumstances indicate.
- So far as practical, sprinklers should be arranged to distribute foam over all combustible surfaces of the main hazard and such surfaces in the immediate vicinity as may be of the same general character. In some cases special deflectors may be necessary, as determined by the conditions of the area to be protected.
- The sprinklers to be so spaced as to protect thoroughly the entire area, so far as practical.
- The design of the system must be such as to insure the appearance of foam at each head not later than 30 seconds after the operation of the sprinkler head or of other release devices.
(Continued on page 608)
Fire Foam Specifications
(Continued from page 598)
Section 4. Piping
- Each closed sprinkler system shall be fed from two independent systems of pipes to convey the foam forming liquids separately to the sprinklers, so that the solutions cannot be mingled until the sprinkler opens.
- Means shall be provided for complete flushing of the system in a rapid and reliable manner in addition to ordinary drainage and where practical pipe should pitch downward 1/2-in. in ten feet.
- For double pipe system with 1/2-inch orifices, the following schedule shall be used:
Section 5. Protection Against Corrosion
- Interior metal surfaces normally exposed to corrosive liquids must be protected in a reliable and permanent manner, as for example, by lead lining when the character of the solution indicates lead to be a suitable protective material. Painting, galvanizing and other methods that apply a very thin coating are not considered suitable.
Section 6 Miscellaneous
- Apparatus approved for water sprinkler service such as pipe, fittings, valves, hangers, etc., shall be used where practical and when special apparatus is necessary, its design and construction shall be equal to the standard required in approved devices for water sprinkler service and before being installed must be approved by the Underwriters having jurisdiction.
- Where practical, metal canopies constructed of No. 20 gage sheet metal on the hazards protected and canopy shall be three feet larger than tank in each direction; sides of canopy shall be not less than three ft. deep.
- All sprinkler heads shall be located as close as possible to the hazards protected, but in no case shall the deflectors of closed systems be more than ten inches below the canopy or ceiling.
- It is recommended that all oil tanks which are protected in sprinklered risks have their sides raised at least one foot above the floor.
- Single piping systems shall be as short as practical, but in no case longer than fifty-ft. and main pipe shall be not less than two inches in size and branch pipe shall be not less than 1 1/4 inches in size.
- Flexible connection should be used only where necessary; suitable hose shall be used and this hose shall be as short as possible, shall be installed so if will not kink, and shall be no smaller than the discharge outlet on the apparatus.
- Suitable alarms shall be installed where required.
Section 7. Maintenance
- These systems must be maintained by the owner in their original condition both mechanically and chemically, and must be inspected thoroughly at least three times per year by the manaufaoturer, and copy of the inspection report sent to the Inspection Department having jurisdiction. Inspections by the manufacturer shall include examinations of valves, pipes, foam sprinklers and alarms, and tests of the chemical solutions.