support sprinkler pipes from secondary steel structure

[Ahmed Abdallah]

I have a situation where the sprinkler pipes are 9 meter away from Steel beams ;consultant advised to install the sprinkler main piping attached to the beam and sprinklers drops will be 9 meters . our proposal to provide low level secondary steel structure to enable us to support the fire piping (max. 100 mm dia.). Can anyone reference the code that acceptable length for sprinkler drop or branch ?