A hydrostatic test for a fire extinguisher, is a National Fire Protection Association requirement. The full inspection and certification schedule is:
- 30 day physical inspection conducted by the owner for all types of extinguishers,
- An annual maintenance certification for all fire extinguishers (recharge if needed)
- A six year comprehensive breakdown and recharge
- 12 year breakdown, hydrostatic test and recharge
The hydrostatic test makes sure that the internal strength of the fire extinguisher is within specifications and that the container does not leak. Some fire extinguishers lose their ability to withstand pressure under the load in which it was designed. This can be caused by environmental effects such as weather, abuse and/ or vandalism or just the age of the fire extinguisher. For the majority of fire extinguishers a water jacket test is utilize for the hydrostatic test and official re-certification.