1 General Provisions
1.0.1 This code was formulated in order to reasonably design the foam extinguishing system, reduce the fire hazard and protect the personal and property safety.
1.0.2 This code is applicable to the design of foam extinguishing systems in the constructed, renovated or extended engineering.
This code is not applicable to the design of foam extinguishing systems at such sites as ships and offshore oil platforms.
1.0.3 Foam extinguishing systems shall not be adopted at the sites containing the following materials:
1 Chemical substances and strong oxidizers such as nitrocellulose and explosive that can be rapidly oxidized in the airless environment;
2 Active metals and chemical substances such as potassium, sodium, alkyl aluminum and phosphorus pentoxide that can generate dangerous chemical reaction in water.
1.0.4 Design of foam extinguishing systems shall not only comply with this code but also comply with those in the current relevant ones of the nation.
2 Terms
2.1 General Terms
2.1.1 Foam concentrate
It refers to the concentrate that can form foam solution when mixed with water in appropriate concentration.
2.1.2 Foam solution
It refers to the foam solution prepared with foam concentrate and water in specific concentration.
2.1.3 Premixed foam solution
It refers to the stored foam solution prepared in advance with foam concentrate and water in specific concentration.
2.1.4 Concentration
It refers to the volume percentage of foam concentrate in the foam solution.
2.1.5 Foam expansion ratio
It refers to the ratio of foam volume to volume of foam solution forming the foam.
2.1.6 Low-expansion foam
It refers to the extinguishing foam whose foam expansion ratio is less than 20.
2.1.7 Medium-expansion foam
It refers to the extinguishing foam whose foam expansion ratio is 20~200.
2.1.8 High-expansion foam
It refers to the extinguishing foam whose foam expansion ratio is greater than 200.
2.1.9 Application rate (density)
Application quantity of foam solution or water per unit time and per unit area, in L/(min?m2).
2.1.10 Fixed system
It refers to the fire extinguishing system composed of fixed foam system water supply pump or foam solution supply pump, foam proportioning sets, foam maker (or head) and piping.
2.1.11 Semi-fixed system
It refers to the fire extinguishing system composed of fixed foam maker connected by water band with part of connecting piping, foam fire truck or engine-driven fire pump.
2.1.12 Mobile system
It refers to the fire extinguishing system composed of fire truck, engine-driven fire pump or pressure water source, foam proportioning sets, foam gun, foam monitor or mobile foam maker, connected by water band.
2.1.13 Balanced pressure proportioning set
It refers to the proportioning set that injects foam concentrate into the pressure flow by the separate foam concentrate supply pump at the set differential pressure, passes through the balanced valve, orifice plate or Venturi tube (or the combination of orifice plate and Venturi tube) and automatically controls the concentration within the range of certain flow pressure or flow.
2.1.14 Direct injection variable pump output proportioning set
It refers to the proportioning set that uses the linkage such as flowmeter and control unit to control the foam concentrate supply pump to inject foam concentrate into the water flow of system at the set proportion.
2.1.15 Pressure proportioning tank
It refers to the proportioning set that mix foam concentrate and water in proportion after the pressure water discharges the foam concentrate from the airtight tank by virtue of Venturi tube. It is divided into bag-type and no-bag-type pressure proportioning tank according to the bag arranged or not.
2.1.16 Around-the-pump proportioner
It refers to the Venturi tube device installed on the bypass piping between water pump outlet and inlet of system, which aspirates the foam concentrate by virtue of the differential pressure between pump outlet and inlet and mix it with water in proportion.
2.1.17 In-line eductor
It refers to the Venturi tube device installed on the water supply line to the foam maker.
2.1.18 Air-aspirating discharge device
It refers to the device, using Venturi tube principle, aspirates the air into the foam solution, mix them to make foam, and then discharge the foam in specific mode, such as foam maker, foam gun, foam monitor and foam head.
2.1.19 Non air-aspirating discharge device
It refers to the device without air-aspirating inlet, in adoption of foam solution such as aqueous film forming and with similar injection mode as water sprinkling, such as water gun, water monitor and water head.
2.1.20 Foam system water supply pump
It refers to the water pump that supplies water to the foam extinguishing system adopting balanced pressure proportioning set, direct injection variable pump output proportioning set and pressure proportioning tank.
2.1.21 Foam solution supply pump
It refers to the water pump that supplies foam solution to the foam extinguishing system adopting around-the-pump proportioner.
2.1.22 Foam concentrate supply pump
It refers to the pump that supplies foam concentrate to the foam extinguishing system.
2.1.23 Foam system pump station
It refers to the site arranged with foam system water supply pump or foam solution supply pump.
2.1.24 Foam station
It refers to the site only arranged with foam proportioning set and foam concentrate tanks, excluding foam system water supply pump or foam solution supply pump.
2.2 Terms of Low-Expansion Foam Extinguishing Systems
2.2.1 Surface application system
It refers to the fire extinguishing system that injects the foam above the surface into the protected tank.
2.2.2 Subsurface injection system
It refers to the fire extinguishing system that injects the foam below the surface into the protected tank.
2.2.3 Semi-subsurface injection system
It refers to the fire extinguishing system in which the foam is injected from the tank bottom, floated to and sprinkled on the surface of combustible liquid through hose.
2.2.4 Foam maker in horizontal position
It refers to the foam maker horizontally installed on Category A, B and C vertical liquid tanks.
2.2.5 Foam maker in standing position
It refers to the foam maker vertically installed on Category A, B and C vertical liquid tank walls.
2.2.6 High back-pressure foam maker
It refers to the device that can aspirate air when the pressure foam solution passes through, generate low-expansion foam and have certain pressure (gauge pressure) at the outlet.
2.2.7 Foam guiding cover
It refers to the device installed at the top of open-top floating roof tank wall, which can make the foam downward flow along the tank wall and prevent foam loss.
2.3 Terms of Medium-And High-Expansion Foam Extinguishing Systems
2.3.1 Total flooding system
It refers to the fire extinguishing system that uses fixed foam maker to sprinkle the foam into the closed or enclosed protected zone and reaches a certain foam flooding depth within the stipulated time limit.
2.3.2 Local application system
It refers to the fire extinguishing system that uses fixed foam maker to sprinkle the foam into the fire hazard position directly or through foam distribution duct.
2.3.3 Enclosure
It refers to the space surrounded by the nonflammable and noncombustible materials.
2.3.4 Foam application rate
Total volume of foam applied per unit time in m3/min.
2.3.5 Foam distribution duct
It refers to the duct that delivers high-expansion foam from the foam maker outlet to the protected zone.
2.4 Terms of Foam-Water Sprinkler Systems and Foam Spray System
2.4.1 Foam-water sprinkler system
It refers to the automatic fire extinguishing system, composed of such assembly as head, alarm valve group and water flow alarm device (water flow indicator or pressure switch), piping, as well as foam concentrate and water supply facilities, that can sprinkle foam and water in turn to the protected zone at the preset time and application density in the case of fire.
2.4.2 Foam-water deluge system
It refers to the foam-water sprinkler system, with open head, that uses the automatic fire detection system installed in the same zone with the head to control the opening.
2.4.3 Closed-head foam-water sprinkler system
It refers to the foam-water sprinkler system with closed water head, including foam-water preaction system, foam-water dry pipe system and foam-water wet pipe system.
2.4.4 Foam-water preaction system
It refers to the closed-head foam-water sprinkler system that uses the automatic fire detection system installed in the same zone with the head to control the opening of relevant equipment and components, make the fire extinguishing media filling the system piping and sprinkle foam and water in turn from the open head after the fire.
2.4.5 Foam-water dry pipe system
It refers to the closed-head foam-water sprinkler system that uses the air or nitrogen of certain pressure filled in the system piping to control the opening.
2.4.6 Foam-water wet pipe system
It refers to the closed-head foam-water sprinkler system that uses the pressure premixed foam solution or water filled in the system piping to control the opening.
2.4.7 Foam spray system
It refers to the automatic fire extinguishing system with foam spray head that can sprinkle foam to the protected equipment or protected zone at the preset time and application density in the case of fire.
2.4.8 Total design area
It refers to the maximum calculated protection area of closed-head foam-water sprinkler system.
