NFPA Vs European Code Queries 2

[TheSpence]

I am a UK based sprinkler designer and am currenlty working on a NFPA 13 project within the UK and would like some clarification on a few issues:

Suction Lift Pumps
i have read that NFPA 20 does not permit centrifugal pumps to be used for suction lift conditions, but vertical turbine pumps are used instead. Local European codes (BS EN 12845) differ from this and i think are in line with older NFPA codes in that you can use centrifugal pumps in suction lift conditions if priming tanks and foot valves are used. In EN 12845 suction lift is defined as the condition when a 1/3 or less of the stored water value is below the pump CL, is there a similar definition within the NFPA codes?

Ceiling Voids
European codes call for void protection when the ceiling void is greater than 800mm (2'8'') in depth (certain other construction method criteria also apply), is there an equivalent figure within NFPA?

Many Thanks in Advance

Spencer Allen

 

[cdafd]

this is out of NFPA 13 2002

is this somewhat what you are looking for::

8.5.7 Skylights. Sprinklers shall be permitted to be omitted from skylights and similar ceiling pockets not exceeding 32 ft2 (3 m2) in area, regardless of hazard classification, that are separated by at least 10 ft (3 m) horizontally from any other skylight or unprotected ceiling pocket.


8.6.7 Ceiling Pockets.
8.6.7.1 Sprinklers shall be required in all ceiling pockets.
8.6.7.2 The requirements of 8.6.7.1 shall not apply where all of the following are met:
(1) The total volume of the unprotected ceiling pocket does not exceed 1000 ft3.
(2) The depth of the unprotected pocket does not exceed 36 in.
(3) The entire floor under the unprotected ceiling pocket is protected by the sprinklers at the lower ceiling elevation.
(4) Each unprotected ceiling pocket is separated from any adjacent unprotected ceiling pocket by a minimum 10 ft horizontal distance.
(5) The unprotected ceiling pocket is constructed of noncombustible or limited combustible construction.
(6) Skylights not exceeding 32 ft2 shall be permitted to have a plastic cover.
(7) Quick response sprinklers are utilized throughout the compartment.

 

[b1ueshift]

There is a difference between NFPA and European codes in that in Europe, there is generally sprinklers above ceilings and in the US, there generally isn't.

NFPA 13 says Concealed spaces formed from non-combustible construction do not require sprinklers. In reality, ceiling voids have some small quantities of combustible materials, but most AHJ's would classify ceiling voids as being non-combustible unless the building is timber construction.