According to NFPA 13, Standard for the Installation of Sprinkler Systems, all sprinkler system piping must undergo a hydrostatic test. The standard test pressure is 200 psi. However, for systems where the maximum system pressure exceeds 150 psi, the test pressure must be 50 psi greater than the maximum system pressure. In this scenario, the maximum system pressure is 175 psi, which is greater than 150 psi. Therefore, the minimum hydrostatic test pressure is calculated as 175 psi + 50 psi, which equals 225 psi. This pressure must be maintained for two hours without loss.

A. 175 psi (12 bar): This is the maximum system working pressure, not the required hydrostatic test pressure, which must be significantly higher to ensure system integrity.

B. 200 psi (13.8 bar): This is the standard test pressure for systems with a maximum working pressure of 150 psi or less; it is insufficient for this higher-pressure system.

D. 250 psi (17 bar): This pressure is not based on the calculation required by NFPA 13 and is unnecessarily high for the specified system pressure.

1. NFPA 13, Standard for the Installation of Sprinkler Systems (2022 Edition).

Section 27.2.1.2: "Where the maximum system pressure exceeds 150 psi (10.3 bar), the system shall be tested at a pressure of 50 psi (3.4 bar) in excess of the maximum system pressure and shall maintain that pressure without loss for 2 hours."

2. Cote, A. E. (Ed.). (2023). Fire Protection Handbook (21st ed.). National Fire Protection Association.

Volume 2, Chapter 8-2, Section: Acceptance Testing of Sprinkler Systems, Page 8-38: "The system is hydrostatically tested for 2 hours at 200 psi (13.8 bar) or at 50 psi (3.4 bar) in excess of the maximum static pressure when static pressure is in excess of 150 psi (10.3 bar)." This section directly supports the calculation for the given scenario.

3. Oklahoma State University, College of Engineering, Architecture and Technology. FST 3333: Water Based Fire Protection Systems.

Course Module: Sprinkler System Acceptance Testing: Course materials specify that hydrostatic testing follows NFPA 13 requirements, stating that systems with a maximum pressure over 150 psi are tested at 50 psi above that maximum pressure.