Question 103Safety & Environmental - 1st Asst/Chief

The correct answer is C) 1000 psi. According to regulations for fixed firefighting systems using CO2 cylinders, all flexible connections between the cylinders and the distribution piping must be renewed or tested at 1000 psi. This ensures the integrity and safety of the connections at the maximum working pressure of the system, which is typically around 850-900 psi for CO2 systems. The other options are incorrect because 2750 psi is too high for a typical CO2 system (option A), 1500 psi is not the correct pressure specified in the regulations (option B), and 300 psi is too low to properly test the connections (option D).