How many insertion markings indicate the end of service life for impulse cartridges with spring-loaded firing pins?

The indication of service life for impulse cartridges with spring-loaded firing pins is characterized by having no limit on the number of insertion markings. These markings are typically used to convey the remaining service life or status of the cartridge, but in this specific case, there is not a predetermined cap on how many markings can be applied. This allows for the possibility of multiple inspections and uses maintaining a valid service life until a specific and critical circumstance dictates otherwise. The absence of a limit ensures flexibility in tracking the operational status of the cartridges without being constrained to a set number of markings, which could be misleading or inadequate for safety assessments.