Cross mains are used to service what in a sprinkler system?

• A. They provide the service to a number of branch lines on which sprinklers are installed
• B. They hold backflow preventers
• C. They connect to the main water supply only
• D. They store spare sprinkler heads

Answer: (A)

Cross mains serve as the distribution network that carries water from the main supply to multiple branch lines where sprinkler heads are installed. This layout lets a single feed serve many sprinklers across different areas, ensuring adequate flow and pressure along all connected branch lines. The other statements don’t fit: backflow preventers are separate devices to prevent contamination, not a function of the cross mains; cross mains aren’t only connected to the main supply but extend out to branch lines; and they don’t store spare sprinkler heads, which are kept in a cabinet or designated storage area.