The extended service should be carried out five yearly intervals for some types of fire extinguishers such as:
- Water fire extinguishers
- Powder fire extinguishers
- Wet chemical fire extinguishers
- Foam fire extinguishers
The same rules apply as per the annual service when it comes to using a competent fire extinguisher maintenance company that are third party accredited.
The extended service covers the same tasks as the annual service, but it will also include discharging the fire extinguisher to ensure that the fire suppressant is compliant. Furthermore, the O rings will be examined and changed as required and the vessel will be inspected for corrosion or cracking. The fire extinguisher valves are also inspected and replaced before refilling and re-pressurisation commences.