Which statement about hydrostatic testing for a 4B195 is true?

Which statement about hydrostatic testing for a 4B195 is true?

• A. The hydrostatic test pressure is three times the normal pressure
• B. The hydrostatic test pressure is the same as the normal pressure
• C. Hydrostatic testing is not required
• D. Hydrostatic testing uses ten times the pressure

Answer: (A)

Hydrostatic testing checks the cylinder’s ability to hold pressure well above normal operating conditions, using a high-pressure load to reveal hidden weaknesses in the shell or seams. For a 4B195 extinguisher, the standard test applies three times the normal service pressure. This substantial margin is what catches flaws that could fail under actual use, while still keeping the test within safe, designed limits. During the test the cylinder is filled with water and pressurized to that higher level; there should be no leaks and no permanent deformation for the cylinder to pass. If anything shows up—leakage, bulging, or cracking—the cylinder isn’t considered safe and would be retired or repaired per procedure. That’s why the statement about three times the service pressure is correct: it provides the necessary safety margin and aligns with how hydrostatic testing is designed to be performed.

Hydrostatic testing checks the cylinder’s ability to hold pressure well above normal operating conditions, using a high-pressure load to reveal hidden weaknesses in the shell or seams. For a 4B195 extinguisher, the standard test applies three times the normal service pressure. This substantial margin is what catches flaws that could fail under actual use, while still keeping the test within safe, designed limits. During the test the cylinder is filled with water and pressurized to that higher level; there should be no leaks and no permanent deformation for the cylinder to pass. If anything shows up—leakage, bulging, or cracking—the cylinder isn’t considered safe and would be retired or repaired per procedure. That’s why the statement about three times the service pressure is correct: it provides the necessary safety margin and aligns with how hydrostatic testing is designed to be performed.