Quantity of foam required-T/ALL.

§ 34.17–5 Quantity of foam required—T/ALL. (a) Area protected. (1) For machinery spaces and pumprooms, the system shall be so designed and arranged as to spread a blanket of foam over the entire tank top or bilge of the space protected. The arrangement of piping shall be such as to give a relatively uniform distribution over the entire area protected. (2) Where an installation is made to protect an oil-fired boiler installation on a flat which is open to or can drain to the lower engineroom or other space, both the flat and the lower space shall be protected simultaneously. The flat shall be fitted with suitable coamings on all openings other than deck drains to properly restrain the oil and foam at that level. Other installations of a similar nature will be considered in a like manner. (b) Rate of application. (1) The rate of discharge to foam outlets protecting the hazard shall be at least as set forth in this paragraph. (2) For chemical foam systems with stored “A” and “B” solutions, a total of at least 1.6 gallons per minute of the two solutions shall be discharged for each 10 square feet of area protected. (3) For other types of foam systems, the water rate to the dry-powder generators or air foam production equipment shall be at least 1.6 gallons per minute for each 10 square feet of area protected. (c) Supply of foam-producing material. (1) There shall be provided a quantity of foam-producing material sufficient to operate the equipment at the minimum discharge rate specified in paragraph (b) of this section for a period of at least 3 minutes. (d) Separate supply of foam-producing material. (1) A separate supply of foam-producing material need not be provided for each space protected. This includes a deck foam system. The total available supply shall be at least sufficient for the space requiring the greatest amount. (e) Water supply for required pumps. (1) The water supply shall be from outside and completely independent of the space protected.