Per NFPA 11, foam system piping shall be hydrostatically tested at a pressure of:

Per NFPA 11, foam system piping shall be hydrostatically tested at a pressure of:

• A. 150 psi
• B. 200 psi
• C. 250 psi
• D. 300 psi

Answer: (B)

The test concept here is hydrostatic testing of foam system piping to verify it can handle the pressures it will face in service. NFPA 11 specifies that foam piping should be hydrostatically tested with water to a pressure of 200 psi. This provides a safe margin above typical operating conditions and helps reveal any leaks, weak joints, or defective components before the system is put into service. Why this pressure is the best fit: 200 psi is the standard test pressure defined for foam piping, balancing a thorough check of integrity without pushing the system to unnecessarily high levels. If you used a lower value, like 150 psi, you might miss defects that only show up at higher pressures. If you went much higher, like 250 or 300 psi, it would exceed the standard requirement and could cause unnecessary risk or equipment stress without added benefit under NFPA 11 guidelines. In practice, the test is performed with water to pressurize the piping, then inspected for leaks and stability, and any deficiencies are corrected before the system is placed into service.

The test concept here is hydrostatic testing of foam system piping to verify it can handle the pressures it will face in service. NFPA 11 specifies that foam piping should be hydrostatically tested with water to a pressure of 200 psi. This provides a safe margin above typical operating conditions and helps reveal any leaks, weak joints, or defective components before the system is put into service.

Why this pressure is the best fit: 200 psi is the standard test pressure defined for foam piping, balancing a thorough check of integrity without pushing the system to unnecessarily high levels. If you used a lower value, like 150 psi, you might miss defects that only show up at higher pressures. If you went much higher, like 250 or 300 psi, it would exceed the standard requirement and could cause unnecessary risk or equipment stress without added benefit under NFPA 11 guidelines.

In practice, the test is performed with water to pressurize the piping, then inspected for leaks and stability, and any deficiencies are corrected before the system is placed into service.