Final answer:
Nonmetallic fire sprinkler pipe must be certified with a minimum pressure rating of 175 psi at 120 degrees F for residential sprinkler installations, to ensure it can handle the conditions during a fire.
Step-by-step explanation:
The correct answer is option 175 psi at 120 degrees F. In residential fire sprinkler systems, nonmetallic fire sprinkler pipe must have a pressure rating of no less than 175 psi at 120 degrees F to ensure safe and reliable operation during a fire event.
It's critical to comply with this requirement as part of adhering to fire safety codes and regulations which are designed to assure the durability and effectiveness of fire suppression systems. This standard ensures that the piping can withstand the thermal expansion that may occur due to the heat from a fire without losing its integrity and causing system failure.