When must a maintenance technician perform a hydrostatic test on an extinguisher?

• A. Every year
• B. On or before the manufacturer's specified interval (often every 5 or 12 years, depending on type)
• C. Only when the cylinder is damaged
• D. It is optional and not required

Answer: (B)

Hydrostatic testing checks the cylinder’s ability to safely handle pressure. The extinguisher shell can develop cracks or lose strength over time, even if it looks fine. Because of that, manufacturers (and safety standards) specify testing the cylinder at set intervals based on the type and construction of the extinguisher, rather than every year or only when damaged. That’s why the correct practice is to perform the test on or before the interval provided by the manufacturer, which is often around 5 or 12 years depending on the extinguisher type. The test is a preventive check, not a routine recharge, and it must be done by a qualified technician, with the extinguisher emptied, tested, then recharged and tagged with the new date.