When we talk about repairing fire extinguishers, what exactly is being repaired?

Many people think that fire extinguisher maintenance is just about changing the label and recharging, but in fact, it's far more than that simple! It is a set of "multi-faceted physical examinations" and "in-depth maintenance" carried out strictly in accordance with national standards, aiming to reliably spray fire extinguishing agents in critical moments and ensure our safety. Just as cars need regular maintenance, fire extinguishers, this "guardian of safety", also require professional care.

Now, let's use plain language to help you understand the ins and outs of fire extinguisher maintenance and become a "safety expert" at home.

I. "Multi-faceted Physical Examination" of Fire Extinguishers: Six Key Steps

A standardized maintenance must include the following six core steps, none of which can be missing. This is just like giving a person a full-body physical examination, where every step is related to life safety.

1. Look at the appearance - both the "face" and the "substance" should be examined

Just as treating a patient begins with "observation, auscultation and olfaction, inquiry, and palpation", a repairman will first transform into a "fire extinguisher doctor", carefully inspecting its appearance:

Bottle body: Check for deep pits, obvious deformations or rust penetration points caused by bumps (pay special attention to the bottom and weld seams). Severe deformations require scrapping (similar to a deflated thermos cup with reduced pressure-bearing capacity).

Nozzle: For plastic pipes, check for aging and cracking (especially at the bends), and for metal pipes, check for rust, blockage and blockage. The smoothness can be judged by blowing air. If it is blocked, clear it first; if not, replace it with a new one.

Valves and handles: Check if the pressing is smooth, if there is any rust or jamming, and if the connection is firm to ensure that it works immediately upon pressing.

Identity identification: The labels on the bottle body, such as the production date, pressure, and fire extinguishing level, must be clear. If the label is worn or lost and no "household registration" can be found, it is judged as unqualified.

2. Measure pressure - "blood pressure" must be normal

Fire extinguishers spray fire extinguishing agents by pressure. Abnormal pressure is a major problem, just like high or low blood pressure in the human body is dangerous.

Standard value: The normal pressure of different types of fire extinguishers varies (for example, dry powder fire extinguishers are usually 1.2-1.5MPa), and the pointer of the pressure gauge should be in the green area.

Low pressure: There might be a gas leak. Use soapy water to check for leaks in the valves and interfaces. If the sealing ring ages, replace it with a new one and pressurize it. If the bottle body leaks, it should be scrapped.

When the pressure is too high: It is more dangerous (possibly due to overfilling or excessively high temperature). Pressure should be released slowly in a well-ventilated area to prevent accidents.

3. Disassemble and repair core components - "Heart Surgery"

This stage tests the technical skills. It requires disassembling the fire extinguisher and conducting in-depth maintenance on key valves.

Replace the sealing ring: Replace the original factory nitrile/fluorine rubber sealing ring and apply special sealing grease to prevent pressure leakage.

Valve repair: Check the elasticity of the spring, the wear of the valve core, and replace the entire core component if it is damaged (ensuring that it sprays immediately upon pressing).

Clean the interior: Use compressed air to blow away any residues and dust inside the bottle to prevent the mixture and caking of new and old fire extinguishing agents.

4. Change the fire extinguishing agent - "Switch to new ammunition

Fire extinguishing agents will expire and deteriorate, and need to be replaced regularly. The "shelf life" varies for different types

Dry powder: If it gets damp and lumps (cannot be rubbed apart), it becomes ineffective. It needs to be emptied completely and the inner cavity should be repeatedly blown and washed before refilling with new dry powder.

Water-based type: If there is stratification, sedimentation or a sour and foul smell, it has deteriorated. The tank needs to be rinsed and dried before new chemicals are added.

Carbon dioxide: Weigh and check. If the weight is more than 5% lighter than the nominal weight, it indicates severe leakage and needs to be refilled.

5. Test the sealing performance - "Water Immersion Test"

After the repair, a sealing test must be conducted to verify the quality of the repair

Water pressure test: Add water at 1.5 times the rated pressure and maintain for 1 minute to check for any leakage or deformation (simulating an extreme safety scenario).

Bubble test: After inflating, immerse the fire extinguisher in water and check if there are any bubbles coming out of the valves and interfaces. If there are any leaks, rework is required.

6. Change accessories and stick new labels - "Wear new clothes and new hats"

The final step is to give the fire extinguisher a "brand new look"

Replace parts: Replace aged nozzles, safety helmets and pressure gauges (the pressure gauges must be qualified after metrological verification).

Label

Maintenance label: Indicate the maintenance unit, date, next maintenance date, and personnel number (" Health Record ");

Warning labels: Remind "Do not expose to direct sunlight", "Do not impact", "Repair required after use".

Traceability QR code: Scan the code to check the full life cycle maintenance records, transparent and reassuring.

Second, fire extinguishers are not "lifetime members" : they must be scrapped upon expiration

Fire extinguishers have a service life. It is very dangerous to use them beyond their service life! According to national standards, the maximum service life calculated from the date of manufacture is as follows:

Types of fire extinguishers

Maximum service life

The main reason

Water-based fire extinguisher

Six years

Steel tanks that have been holding water for a long time are prone to rusting from the inside (which is hard to detect from the outside and has a decreased pressure-bearing capacity).

Dry powder fire extinguisher

Ten years

Dry powder is prone to caking over a long period of sedimentation and corrodes the tank body. Corrosion accelerates in a humid environment

Carbon dioxide fire extinguisher

Twelve years

Long-term exposure to high pressure (about 5.17MPa at normal temperature of 20℃) makes metals prone to fatigue (similar to the repeated bending and breaking of iron wire).

Key reminder: No matter how new the appearance is, it must be compulsorily scrapped upon expiration (just like food that has passed its expiration date, it should not be used at risk). Scrapping should be handled by professional institutions (drilling holes in the tank body/flattening), and a scrapping ledger should be established to prevent refurbishment and reuse.

Third, if these situations occur before the expiration date, the service should be immediately discontinued

If any of the following situations are found during routine inspections, the vehicle should be sent for repair or scrapped immediately:

Impact and deformation: The tank body has large pits and severe rust (rust through or peeling), especially the rust at the bottom is often more serious.

Accessory damage: The pointer of the pressure gauge is inaccurate or damaged (does not return to zero, the dial is cracked), the handle/pressure handle is loose, the nozzle is aged and cracked.

Air leakage: After inflation, the pressure drops rapidly, or there is a "hissing" sound of air leakage at the valve.

Fire extinguishing agent failure: Dry powder clumps and cannot be poured out, water-based agents stratify and stink.

Experienced in special scenarios: Used at fire scenes or placed for a long time in high-temperature environments such as boiler rooms (internal structure may be damaged);

Missing labels: The labels are severely worn and cannot identify key information such as the production date and pressure rating.

Processing procedure: Affix a "Do Not Use" label, place it in a safe area away from people and fire sources, contact a qualified maintenance unit for handling, and update the fire extinguisher ledger at the same time.

Four. Tips for Daily Self-Inspection

In addition to regular professional maintenance, it is recommended to conduct a simple inspection once a month. Remember the mnemonic: "Pressure green zone, neat appearance, intact accessories, clear labels."

Check the pressure: Is the pointer of the pressure gauge in the green zone?

Check the appearance: whether there is obvious rust or deformation;

Check the accessories: whether the nozzle is in good condition and whether the safety pin is normal.

Check the label: Whether it is within the validity period.

Summary

Maintenance: Seek a qualified professional institution for a "comprehensive physical examination and maintenance". Do not make do with roadside stalls. Be responsible for your life safety.

Scrapping: Strictly enforce the "compulsory retirement" upon expiration. Do not use beyond the expiration date just because it looks okay.

Daily: Pay more attention to appearance and abnormal pressure. Develop the habit of monthly inspection to prevent potential problems before they occur.

Be kind to the fire extinguisher so that it can stand up for you in critical moments. Safety is no small matter. Start by understanding the maintenance of fire extinguishers.