Deck foam system nghĩa là gì trong hàng hải

It is required by SOLAS convention to install fixed foam fire-fighting system on cargo decks of oil and chemical tankers.

Flammable gas volatilized from liquid fuel explosively burns upon ignition and flames instantly spread over whole surface of the fuel oil. To combat such a fire with intense flames, it is required to completely cover the burning fuel surface in order to avoid the exposure to air. The flammable gas is constantly volatilized from the liquid fuel even after the fire has been successfully extinguished. This gas could be re-ignited by remaining heat on the equipment or breakage of the foam blanket by a fallen object, leading to a secondary fire. To prevent re-ignition, it is essential to cover the burning surface with a tough and durable foam blanket to suppress the volatilization of flammable gas, and to cool the surface of the fuel and the heated equipment down to the flash point. At present, the deck foam fire-fighting system is the only solution to satisfy these multiple requirements.

Our deck foam fire-fighting system is called “Air-foam system”, agitating and aerating the streams of the foam liquid and seawater in the piping by what is called “jet effect” to generate foam.

Features / Advantages

The foam produced by this system excels foam produced by chemical reaction in fire and oil resistance. The foam liquid adopted for our system is perfectly compatible with seawater to generate sufficient quality of foam.

[CGFR 69–72, 34 FR 17481, Oct. 29, 1969, as amended by CGD 74–127, 41 FR 3846, Jan. 26, 1976; CGD 77–057a, 44 FR 66502, Nov. 19, 1979]

§ 34.20-3 Cargo area definition—T/ALL.

(a) For the purpose of this subpart, the term cargo area is defined as the maximum beam of the vessel times the total longitudinal extent of the cargo tank spaces.

§ 34.20-5 Quantity of foam required—T/ALL.

(a) Area protected. Systems of this type are designed to give primary protection to the spaces over the cargo tanks.

(b) Rate of application. The water rate of the foam production equipment shall be determined as follows:

(1) For usual petroleum products the rate of supply of foam solution shall be not less than the greatest of the following:

(i) 0.6 liters/min per square meter of cargo tanks deck area, where cargo tanks deck area means the maximum breadth of the ship multiplied by the total longitudinal extent of the cargo tank spaces;

(ii) 6 liters/min per square meter of the horizontal sectional area of the single tank having the largest such area; or

(iii) 3 liters/min per square meter of the area protected by the largest monitor, such area being entirely forward of the monitor, but not less than 1,250 liters/min.

(2) For polar solvent products (e.g. alcohols, ketones, etc.) the water rate shall be determined for each vessel. The rate will depend upon the vessel design, products to be carried and foam system to be used.

(c) Supply of foam-producing material. Each deck foam system must have a supply of foam-producing material sufficient to operate the system at its designed rate of foam production for the following periods:

(1) For installations contracted for on or after January 1, 1970, 15 minutes without recharging, except as required in of this section.

(2) For installations on ships that have a keel laying date on or after January 1, 1975, 20 minutes without recharging.

(d) Separate supply of foam-producing material. Where the same foam-producing material may be used for this system as well as a fixed foam system, separate supplies need not be provided for each space protected. The total available supply shall be at least sufficient for the space requiring the greatest amount.

(e) Water supply. Suitable pumps shall be provided capable of producing the required water rate. The fire pumps required by subpart 34.10 may be used for this purpose; however, the operation of the deck foam system shall not interfere with the simultaneous use of the fire main system.

[CGFR 65–50, 30 FR 16694, Dec. 30, 1965, as amended by CGFR 69–72, 34 FR 17481, Oct. 29, 1969; CGD 74–127, 41 FR 3846, Jan. 26, 1976; CGD 95–028, 62 FR 51199, Sept. 30, 1997]

§ 34.20-10 Controls—T/ALL.

(a) The foam agent, its container, measuring devices, and other items peculiar to this system shall be of an approved type.

(b) The foam agent container and the main controls for operating the system shall be located in a protected space not likely to be made inaccessible in the event of a fire in any portion of the cargo area.

(c) Complete, but simple instructions for the operation of the system shall be located in a conspicuous place at or near the controls.

(d) All valves shall be marked as required by § 35.40–17.

(e) The deck foam system on each tankship that has a keel laying date on or after January 1, 1975, must be capable of being actuated, including introduction of foam to the foam main, within three minutes of notification of a fire.

[CGFR 65–50, 30 FR 16694, Dec. 30, 1965, as amended by CGD 74–127, 41 FR 3846, Jan. 26, 1976]

§ 34.20-15 Piping—T/ALL.

(a) All piping, valves, and fittings shall meet the applicable requirements of subchapter F (Marine Engineering) of this chapter.

(b) All piping, valves, and fittings of ferrous materials shall be protected inside and outside against corrosion unless specifically approved otherwise by the Commandant.

(c) The piping and outlet arrangement shall allow the required rate of applications as contained in , to any portion of the open deck of the cargo area through the use of the mounted and hand-held appliances that are provided. At least 50 percent of the required rate of application shall be from the mounted appliances. One or more hose outlets for hand-held appliances shall be provided at each foam station. For enclosed spaces, application of at least 1.6 gallons per minute water rate for each 10 square feet of the enclosed area for 5 minutes is acceptable. For the purpose of this paragraph, all piping is assumed to be damaged in way of the fire and an adequate number of valves shall be fitted to prevent loss of foam by closing valves to damaged piping.

(d) All piping, valves, and fittings shall be securely supported, and where necessary, protected against injury.

(e) Drains and dirt traps shall be fitted where necessary to prevent the accumulation of dirt or moisture.

(f) Piping shall not be used for any other purpose than firefighting, drills, and testing.

(g) Tankships of 100,000 or more DWT (metric) and combination carriers of 50,000 or more DWT (metric) that have a keel laying date on or after January 1, 1975, must have at least one foam station port and at least one foam station starboard that are separated from each other by a distance equal to at least one-half the beam of the vessel:

(1) At the housefront or aft of the cargo area in a location that is accessible to the crew for fighting a cargo and a pumproom fire; and

(2) If the tankship has a forward accommodations house, at the after boundary of that house.

[CGFR 65–50, 30 FR 16694, Dec. 30, 1965, as amended by CGD 72–138, 39 FR 7790, Feb. 28, 1974; CGD 74–127, 41 FR 3846, Jan. 26, 1976]

§ 34.20-20 Discharge outlets—T/ALL.

(a) Discharge outlets shall be of an approved type.

(b) At least one mounted foam appliance shall be provided for each station that is required in .

(c) The number of hand-held appliances provided shall be at least equal to the number of hose outlets at the two foam stations having the most hose outlets. Hand-held appliances shall be stowed in a well marked, readily accessible position that cannot be isolated by a fire involving the cargo tanks.

[CGFR 65–50, 30 FR 16694, Dec. 30, 1965, as amended by CGD 72–138, 39 FR 7790, Feb. 28, 1974]

§ 34.20-25 Foam monitor capacity—T/ALL.

The capacity of each foam monitor on ships that have a keel laying date on or after January 1, 1975, must be at least 3 liters per minute per square meter (.073 gallons per minute per square foot) of cargo area protected by that monitor.