Hazen -Williams Friction Loss Equation

[Blufire]

I want to know if the Hazen -Williams Friction Loss Equation is mentioned in CEN standards for fire sprinkler systems (please tell me in which EN (CEN) fire suppression standard).
Thank you!

 

NFPA 1999 edition spells out that the HW equation is to be used. See 8-4.2.1

Hope this helps.

-- Trashcan Man