An Atash Behram (Fire of Victory) is the highest grade of a fire that can be placed in a fire temple. The establishment and consecration of this fire is the most elaborate than all the other grades of fire. It involves the gathering of 16 different types of fire which is fires gathered from 16 different sources, including lightning, fire from a cremation pyre, fire from trades where a furnace is operated, and fires from the hearths as is also the case for the Atash Adaran. Each of the 16 fires is then subject to a purification ritual before it joins the others. 32 priests are required for the consecration ceremony, which can take up to a year to complete.
Courtesy: Zaver Bomanbehram