We are still waiting for NFPA reply to the following question sent by our e-mail of 10 August 2016.
Please refer to NFPA-13, 18.104.22.168, 1.e. “Wire used for restraint shall be located within 2ft(610mm) of a hanger. The hanger closest to a wire restraint shall be of a type that resists upward movement of a branch line.
Our question is what is the hanger type that resists upward movement of a branch line.
In general, we shall provide hangers with 9.5mm Dia. rod at every 3.5m distance of branch lines. The hanger shall be used of ring type with turn-buckle but not used of adjustable swivel ring or clevis hanger type.
In that case, the questioning point is whether the above hanger itself shall be enough to resist upward movement or additional reinforced steel angle shall be provided and attached to the hanger rod.
Please reply and thank you.
J S Kim