When is maintenance performed on fire extinguishers requiring a hydrostatic test?

Maintenance on fire extinguishers requiring a hydrostatic test is performed after the hydrostatic test. This process ensures that the extinguisher is safe to use and operates effectively. The hydrostatic test is conducted to evaluate the integrity and pressure-holding capability of the cylinder. After the test confirms that the unit is structurally sound and free of leaks, maintenance can address any additional concerns, including replacing the valve assembly, inspecting the extinguisher's internal components, and ensuring that it meets all operational standards. This sequence guarantees that only extinguishers that have passed the testing phase receive further maintenance, thereby enhancing safety and reliability.