An assembly of fittings, pipe, flexible pipe, and/or couplings that permits movement in all directions to accommodate seismic differential movement across building seismic separation joints.

#Definition

An assembly of fittings, pipe, flexible pipe, and/or couplings that permits movement in all directions to accommodate seismic differential movement across building seismic separation joints.

Seismic separation assemblies include traditional assemblies as shown in Figure (1) and seismic loops as shown in Figure (2).
Seismic separation assembly according to NFPA 13 -2019 edition
Figure (1)

Seismic separation assembly according to NFPA 13 -2019 edition
Figure (2)
The extent of permitted movement should be sufficient to accommodate calculated differential motions during earthquakes. In lieu of calculations, permitted movement can be made at least twice the actual separations, at right angles to the separation as well as parallel to it.

#General_requirements

An approved seismic separation assembly shall be installed where sprinkler piping, regardless of size, crosses building seismic separation joints at ground level and above.

Seismic separation assemblies shall consist of flexible fittings or flexible piping so as to allow movement sufficient to accommodate closing of the separation, opening of the separation to twice its normal size, and movement relative to the separation in the other two dimensions in an amount equal to the separation distance.

The seismic separation assembly shall include a fourway brace upstream and downstream within 6 ft (1.8 m) of the seismic separation assembly. Each four-way brace should be attached to the building structure on opposite sides of the seismic separation joint.

Bracing shall not be attached to the seismic separation assembly.

Fig:-02

Fig:-01