FlexHead® Industries satisfactorily completed full-scale seismic qualifications testing at the Structural Engineering Earthquake Simulation Laboratory located at the State University of New York at Buffalo.

Tests were conducted using the International Code Council (ICC) acceptance criteria “ICC-ES AC-156 Seismic Qualification Testing of Nonstructural Components”.  This is the first time a sprinkler component has been seismically certified using test criteria accepted by the ICC.

The latest version of the IBC defers to ASCE 7 for the sprinkler/ceiling design in Seismic Design Categories (9SDC) C and D, E & F.

In Seismic Design Category C, suspended ceilings are to be designed and installed in accordance with Ceilings & Interior Systems Construction Association (CISCA) recommendations for Zones 0-2; and sprinkler head and other penetrations shall have a minimum of ¼ inch clearance on all sides.

In Seismic Design Categories D, E & F, suspended ceilings are to be designed and installed in accordance with CISCA recommendation for seismic Zones 3 and 4 with some additional requirements.  Except where rigid braces are used to limit lateral deflections, sprinkler heads and other penetrations shall have a 3-inche oversized ring, sleeve, or adapter through the ceiling to allow for free movement of at least 1 inch of ceiling movement in all horizontal directions.

Flexible sprinkler connections provide characteristics that exceed the most stringent seismic code requirements.  The flexibility of the hose allows the head to move with the ceiling in any direction during a seismic event without causing damage to the sprinkler system.  Flexible sprinkler connections also eliminate the problem of sprinkler drops jumping out of their penetration holes because of vertical motions and snapping the sprinkler when the drop tries to reinsert itself.

It is worth noting that flexible sprinkler connections are produced differently by each manufacturer.  One should not make the broad assumption that every flexible sprinkler drop will perform the same way in a seismic event.  There is no substitute for testing data.


The following seismic qualification tests and resulting document was prepared by the Department of Civil, Structural and Environmental Engineering at State University of New York.

Download (PDF, 1.3MB)