What are the treatment methods for different usage states of fire extinguisher after use

Fire extinguishers are the most critical firefighting equipment for extinguishing initial fires. They are of various types and widely used. After actual use, fire extinguishers will present multiple states according to their spraying degree and physical state. The treatment methods required for each state are significantly different. If improperly operated, it may cause equipment failure, safety hazards or violations of laws and regulations.

State 1: The fire extinguisher has been completely sprayed
The fire extinguisher has been completely sprayed at the fire scene, the extinguishing agent and propellant gas have been exhausted, there is no residual pressure in the nozzle, and the pressure gauge pointer falls back to the red area. This state is the most common, especially after the initial fire is successfully extinguished.
The treatment methods are as follows:
Immediately mark "used" or "empty bottle" and affix a conspicuous label;
Store in a special empty bottle temporary storage area to prevent misuse;
Send to a unit with a "Fire Equipment Maintenance License" for inspection as soon as possible;
After professional personnel confirm that there is no structural damage, clean, dry, refill, and re-pressurize;
Replace vulnerable parts such as nozzles, rubber rings, safety pins, etc.;
Attach a maintenance qualification label and record the next inspection time;
If the bottle body is obviously corroded, deformed or exceeds the service life, the mandatory scrapping procedure should be implemented.

State 2: Partial discharge of fire extinguisher
The fire extinguisher was activated in an emergency, but because the fire was controlled or the operation was interrupted, only part of the fire extinguishing agent and pressure were released. This state is more complicated, and there is still residual pressure and chemical agents inside the device, which has a higher safety risk.
The treatment methods are as follows:
It is forbidden to use it manually again or spray it without authorization;
Put the fire extinguisher in a safe storage cabinet with ventilation and light protection;
Use obvious signs to indicate "partial use, dangerous residual pressure";
Hand it over to the fire equipment maintenance unit for professional pressure relief as soon as possible;
Gradually release the residual gas and fire extinguishing agent in a special pressure relief device;
Disassemble and check whether the sealing performance of the bottle and valve is damaged;
Flush the inside, refill the original fire extinguishing agent and re-pressurize;
If it is confirmed that the gas valve is stuck or the nozzle is blocked, the key components should be replaced and then the factory-level inspection should be carried out.

State 3: The fire extinguisher is unsealed but not sprayed
Some fire extinguishers may be removed due to operating errors, the safety pin is removed or the handle is pressed but not actually sprayed. This state is more common during fire drills and false alarms. The appearance of the fire extinguisher has not changed, but it is impossible to determine whether its performance remains intact.
The treatment methods are as follows:
Determined as "unqualified state", it shall not be put into normal use again;
Mark "unsealed but not sprayed", and record the operator, time and reason;
Send to the maintenance unit for full process inspection;
Check whether the internal pressure is leaking, whether the sealing ring is displaced or damaged;
If there is no pressure loss, simple repairs such as resetting calibration and replacing safety pins can be performed;
If there is pressure fluctuation or structural looseness, a complete filling and inspection process is required;
Under special circumstances, factory return or scrapping can be applied.

State 4: Fire extinguisher appearance damage or abnormal pressure
After use or during transportation, the fire extinguisher may be hit, dropped, exposed to high temperature, etc., resulting in dents and rust on the bottle surface, or the pressure gauge pointer deviates from the normal area.
The treatment methods are as follows:
First, conduct a visual inspection of the appearance to determine whether there is serious structural damage;
Check the pressure gauge. If the pressure is lower than the normal range, it should be judged as failure;
If there are irreparable damages such as deformation of the bottle, cracks in the weld, loose base, etc., it should be forced to scrap;
If it is only a slight external injury but the bottle is intact and the structure is not deformed, a water pressure test can be performed for verification;
For fire extinguishers used in high temperature environments, the fire extinguishing agent should be tested to see if it is ineffective and the propellant gas is expanded;
Once it is confirmed that the fire extinguisher is no longer safe, it should be recycled through a regular hazardous waste treatment company.

State 5: Fire extinguisher is not used but exceeds the maintenance or service life
Even if the fire extinguisher has never been used, once it exceeds the validity period or annual inspection period, it must be treated as a special state. Generally, fire extinguishers should be inspected once a year and the service life shall not exceed 10 years (the specific details shall be subject to the product manual).
The treatment methods are as follows:
If the annual inspection period has only been exceeded but the service life has not been exceeded, it should be sent for periodic inspection, pressurization, and labeling;
If the service life has been exceeded, the scrapping process must be carried out;
The scrapping process includes emptying the fire extinguishing agent, removing parts, flattening the bottle, and metal classification;
All scrapping processes should comply with the "Hazardous Waste Storage Pollution Control Standards" and "Firefighting Equipment Scrapping Regulations".