The maximum area of coverage specified in NFPA 13 for standard spray or pendent sprinklers in a hydraulically calculated system in extra hazard, where density >= .25 gpm is:

The maximum area of coverage specified in NFPA 13 for standard spray or pendent sprinklers in a hydraulically calculated system classified as extra hazard is indeed 100 square feet when the density is equal to or greater than 0.25 gallons per minute (gpm). NFPA 13 outlines specific guidelines for sprinkler system design, including coverage areas that relate to the classification of the hazard presented in a building.

In extra hazard situations, the risk of fire is higher due to the presence of materials and processes that can ignite and spread flames quickly. As such, the code specifies stricter requirements for sprinkler coverage to ensure adequate fire protection. The maximum area of 100 square feet per sprinkler is a key rule in managing this risk effectively.

Understanding these specifics helps in designing and implementing fire suppression systems that comply with NFPA standards, ensuring that buildings are protected adequately against the risk of fire.