Inspection and Maintenance. The main relevant guidance covering this subject is
BS 5306-3:2009: Fire extinguishing installations and equipment on premises.
NEBOSH National Diploma - Unit C | Workplace and Work Equipment Safety
Inspection and Maintenance The main relevant guidance covering this subject is BS 5306-3:2009: Fire extinguishing
installations and equipment on premises. Commissioning and maintenance of portable fire extinguishers. Code of practice. Regular (at least monthly) visual inspections should be carried out. This is a straightforward check that the extinguisher is still there; that it is unused and undamaged; has not been tampered with; is accessible and visible; the instructions on it are legible; and that any pressure gauges indicate that it is within operational limits. In addition, all portable fire extinguishers will need to undergo an annual basic service and also: •
either an overhaul every ten years (halon and carbon dioxide types only) or
•
an extended service (all other types – typically this is required every five years).
An extended service includes a test discharge of the extinguisher. An overhaul includes a test discharge and also a pressure test of the body shell. We will look at the requirements for the basic service. These vary depending on the mode of operation (e.g. stored pressure vs. cartridge) and/or the extinguishing agent.
Stored Pressure Type These are pressurised containers. The extinguishing agent is expelled when the pressure is released using the operating trigger. Water, water-based (e.g. foam and wet chemical types), powder and primary sealed powder are commonly found as stored pressure types. Primary sealed powder extinguishers are a type of stored pressure extinguisher where the head can be detached without releasing the pressurised powder (because it has an additional seal which is only pierced during activation of the extinguisher). The basic maintenance regime is the same for all these types of stored pressure devices and comprises the following checks (summarised from Table D.2, Annex D of BS 5306-3), which should be carried out in order: •
Check safety clip and indicators to see if the extinguisher has been used.
•
Check that the pressure is correct (many extinguishers have a pressure gauge fitted, otherwise a pressure gauge may be attached to a special connection).
•
Check for damage (corrosion, dents, etc.) and replace as necessary.
•
Weigh the extinguisher (losses of more than 10% need a full recharge).
•
Check the operating instructions (legible, correct).
•
Where the operating head is designed to be removable without discharging the contents (e.g. primary sealed powder type), do so and check/clean/lubricate the operating mechanism.
•
Remove and replace the safety pin, checking operating lever for damage and free movement.
•
Check hoses, discharge horn and nozzle are not blocked and there is no damage. Replace the seals for these components.
The extinguisher is reassembled on completion of the checks and details are completed on the maintenance label. An inspection report will detail the current state of the extinguisher.
Carbon Dioxide The basic service regime should be similar to the above with the exception of the second point in the list (pressure is not checked for carbon dioxide extinguishers).
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Element C3 | Workplace Fire Risk Assessment
NEBOSH National Diploma - Unit C | Workplace and Work Equipment Safety
Cartridge Operated Rather than the propellant being in the same chamber as the extinguishing agent, these types of extinguishers are fitted with a separate cartridge which contains the propellant. Piercing the cartridge releases the propellant which, in turn, expels the extinguishing agent. Water, waterbased and powder are commonly found as cartridge types (as well as stored pressure types). The basic service should be the same as for the stored pressure type (as outlined above) except the pressure check is not relevant (so not carried out) and the following additional checks are made: •
•
Open the extinguisher (unscrew the head), removing the gas cartridge, and then: −
For water/water-based extinguishers, pour out the contents from the body and check interior for corrosion (or, if fitted, remove and check any inner container for leakage). The original charge may be re-used after inspection if the liquid is still in good condition, otherwise replace with fresh.
−
For powder extinguishers, check the powder for caking, lumps, etc. and re-charge if necessary. Check the interior body for corrosion, etc.
Check operating mechanism (for free movement) and air passages (should be unobstructed).
© RRC Training
Element C3 | Workplace Fire Risk Assessment
