Safe Maintenance Practice For Servicing of Fire Extinguisher

  1. While opening any extinguisher for maintenance,
    • ensure that there is no residual pressure in any hose and/or nozzle assembly;
    • Unscrew the cap or valve assembly slowly for two or three turns only, to allow any residual pressure to escape via the vent holes and do not unscrew it further until all pressure is released. Keep away the head and body to avoid injuries;
    • Do not depend on pressure indicating devices like gauges (in the cases of stored pressure Build-up in the container. This reaction may become apparent only after a few weeks. Type extinguisher) to verify whether the container is under pressure or not, as they could malfunction;
    • If pressure is not being released after unscrewing the cap or valve assembly two or three turns, then do not unscrew it further without taking appropriate safety measures; sudden release of pressure may eject parts, cap assembly, or the contents of the extinguisher. The use of suitable clamping arrangements and appropriate personal protection is advisable;
    • Under no circumstances should the valves of carbon dioxide or stored pressure type extinguisher of gas cartridges/ containers be attempted to be removed under filled conditions; and
    • At all times when attempting to remove parts from extinguisher at the time of inspection/ maintenance, persons, should ensure that they are clear of any parts which may be ejected.

 

  1. Other Safety Guidelines
    • Dry powder extinguisher should be opened only in the driest available conditions and for the minimum time, necessary for examination, to minimize the effect of atmospheric moisture on the powder. Moisture causes caking of the powder.
    • It is even more important that mixing or cross-contamination of different types (BC/ABC/ D) of powder be avoided as it may cause chemical reaction resulting in a dangerous pressure Build-up in the container. This reaction may become apparent only after a few weeks.
    • All sealing components should be cleaned and properly lubricated to prevent leakage afterRecharge.
    • Check pressure indicating devices to ascertain that it gives proper readings.
    • Never connect a stored pressure extinguisher to be charged directly to the high pressure source. Connecting directly to the high pressure source could cause damage or even rupture of the container and may result in the injury.
    • Only those gas cartridges which will suit the particular type and capacity of the extinguisher should be used. Do not use higher capacities than recommended.
    • Certain recharging materials deteriorate with age, exposure to excessive temperature and moisture. Storage of recharge materials for long periods should be avoided.
    • Normal workshop compressors deliver air with high moisture content. Moisture traps will only remove the moisture partly, and may lead to caking of powder, hydrolysis of halogenated agents, clogging of pressure gauges and internal corrosion. Blowers/dryers should be used to clean hose and hose fittings.
    • On all higher capacity dry powder and carbon dioxide extinguisher equipped with a shut-off nozzle, the hose (without the nozzle) should be removed and tested annually