I am installing sprinkler protection within single row racks. The protection is in accordance with NFPA 30 Table 220.127.116.11 and in accordance with layout 18.104.22.168 - layout 3. Layout 3 calls for a single line of in-rack sprinklers in the longitudinal flue space. This is possible with the racks that are located against the walls. There does not appear to be guidance in NFPA 30 or NFPA 13 regarding the location of the sprinkler line in a rack that is not located against a wall (it is centered in the room). I would normally locate the in-rack branchline within the rack (just on opposite side of the rack upright) although the owner intends at some point in the future to install another rack section creating double row racks. If we installed it off the side of the rack, the owner would not need to modify the sprinkler coverage later when they install additional racks. Would it be acceptable by code to have the sprinkler protection located to the side of the rack (not under the wire shelves) as the owner would like (see detail showing what the owner is proposing)?