Reference: NFPA 13 (2019 Edition)
188.8.131.52 Friction Loss
184.108.40.206.1 Pipe friction loss shall be calculated in accordance with the Hazen–Williams formula with C values from Table 220.127.116.11.1, as follows:
(9) Friction loss shall be excluded for the fitting directly connected to a sprinkler.
What does "directly connected" to a sprinkler means? Suppose, a reducer-couple + a short riser nipple is attached to a tee in a branchline from which a sprinkler head tops it, are these add-ons excluded from the friction loss calculation?