46 CFR 108.441: Piping and discharge rates for CO2 systems.

(a) The size of branch lines to spaces protected by a CO2 system must meet Table 108.441.

(b) Distribution piping within a space must be proportioned from the supply line to give proper distribution to the outlets without throttling.

(c) The number, type, and location of discharge outlets must distribute the CO2 uniformly throughout the space.

Table 108.441—CO2 System Pipe Size

CO2 supply in system, kilograms (pounds) Minimum pipe size (inches), millimeters (inches)

45 (100) 12.7 (1⁄2).

104 (225) 19.05 (3⁄4).

136 (300) 25.4 (1).

272 (600) 31.75 (11⁄4).

450 (1,000) 38.10 (11⁄2).

1,110 (2,450) 50.80 (2).

1,130 (2,500) 63.5 (21⁄2).

2,023 (4,450) 76.2 (3).

3,229 (7,100) 88.9 (31⁄2).

4,750 (10,000) 101.6 (4).

6,818 (15,000) 114.3 (41⁄2).

(d) The total area of all discharge outlets must be more than 35 percent and less than 85 percent of the nominal cylinder outlet area or the area of the supply pipe, whichever is smaller. The nominal cylinder outlet area in square centimeters is determined by multiplying the factor 0.0313 by the number of kilograms of CO2 required. (The nominal cylinder outlet area in square inches is determined by multiplying the factor 0.0022 by the number of pounds of CO2 required). The nominal cylinder outlet area must not be less than 71 square millimeters (0.110 square inches).

(e) A CO2 system must discharge at least 85 percent of the required amount within 2 minutes.