N.Y.C. Admin. Code § 27-938: § 27-938 Size of standpipe risers.

The size of standpipe risers shall be in accordance with Table 17-1.

TABLE 17-1 Size of Standpipe Risers

Height1

Minimum Riser Size Required (I.P.S.)

150 ft. or less

4 in.

Greater than 150 ft

6 in.

Note for Table 17-1: 1 The height shall be that of the individual riser to the highest hose outlet (not including manifold outlets) from the level of the entrance floor at street level at which the riser begins.