Nov 2011

Changes to FM Global Data Sheet 8-9 – Storage of Class 1, 2, 3, 4 and Plastic Commodities

Between March 2010 and now, FM Global has made two revisions to this Data Sheet.

In September 2010 the following revisions were made:

  • The maximum linear and area spacing for K25.2EC (K360EC) sprinklers when used for ceiling-only designs have been reduced to 12 ft. (3.6 m) and 144 sq. ft. (13.4 sq. m), respectively. When used with in-rack sprinklers the maximum spacing can be increased to 14 ft. (4.2 m) and 196 sq. ft. (18 sq. m), respectively.
  • The ceiling-level design for the K25.2EC (K360EC) pendent quick-response sprinkler for ceiling heights up to 35 ft. (10.5 m) was modified from 6 sprinklers to 8 sprinklers, for Class 1 through cartoned unexpanded plastic commodities, whether in a rack or non-rack storage arrangements.
  • The ceiling-level design for the K25.2 (K360) pendent standard-response sprinkler for ceiling heights of 25 ft. (7.5 m) and 30 ft. (9.0 m) for Class 4 and cartoned unexpanded plastic commodities was reduced from a pressure of 15 psi (1.0 bar) to 10 psi (0.7 bar).
  • The ceiling-level designs for the K25.2EC (K360EC) pendent and upright quick-response sprinkler for ceiling heights up to 25 ft. (7.5 m) were modified for Class 1 through cartoned expanded plastic commodities, whether in a rack or non-rack storage arrangements.
  • The ceiling-level design for the K25.2EC (K360EC) pendent and upright quick-response sprinkler was changed in non-rack storage of Class 4 and cartoned unexpanded plastic commodities for a ceiling height of 30 ft. (9.0 m).
  • Design guidelines for various Engineering Bulletins were incorporated into this version.

In July 2011, the following revisions were made:

  • Previous editions made reference to only hazards associated with combustible open-top containers. The latest edition notes that the hazard associated with open-top containers (faster horizontal fire spread) are irrelevant to the construction of the container, and that similar protection criterion is needed.
  • Water delivery time for dry-pipe, preaction and similar type of sprinkler systems has been defined. It can be either the point in time when pressure at the most remote sprinkler reaches or surpasses the design pressure for the sprinkler system, or, the point in time when the most hydraulically remote sprinkler system equipped with an automatic system valve opens. The standard water delivery time has been set at 60 seconds, though it can be reduced to 40 seconds for the four most remote heads (two heads on two lines). In special cases some head sizes can be reduced to 25 or 20 seconds.
  • Fire Protection Scheme 8-9A was previous referred to as Scheme A. It was changed to eliminate confusion with Scheme A that is used for the storage of flammable and combustible liquids (Data Sheet 7-29).
  • As a special application, in-rack sprinklers can be limited to the longitudinal flue space of single- and double-row open-frame racks for Class 1 through cartoned plastic commodities provided the ceiling and in-rack systems are wet-pipe only.
  • As a special application, clarified protection requirements for storage of Class 1 through uncartoned unexpanded plastic commodities in single- and double-row racks using horizontal barriers and in-rack sprinklers in the longitudinal flues only.
  • Ceiling-only protection requirements for uncartoned unexpanded and expanded plastic commodities (Tables 10 and 11) have been expanded to include more discrete ceiling heights. Accordingly the hydraulic design for ceiling-level sprinkler systems supplemented with in-rack sprinklers (Table 13) has been expanded for these commodities.
  • Design guidelines for various Engineering Bulletins were incorporated into this version.

Risk Logic, Inc. can be of assistance regarding the changes to Data Sheet 8-9 and how they affect your facility.