Fire  Extinguisher  Service  and  Inspection

Anubis Systems Technologies’ trained professionals are committed to ensuring your project’s fire extinguishers are serviced, maintained, and inspected to the highest standards in the industry.  We partner with several Lower Mainland service facilities to ensure timely recharging and the properly certified internal maintenance and hydrostatic testing is performed on your portable extinguishers.  Our services are competitively priced and leave nothing to chance.

For more information you can email us or telephone (778) 863-7147.



In order to understand how a fire extinguisher works, we need to delve into some basic fire chemistry (don’t worry, you won’t require advanced chemical knowledge to participate).

Many fire service industry websites commonly mention something called the fire triangle.  Simply put, imagine a triangle with three equal sides (the mathematical term for one is an equilateral triangle).  Well, each side of the fire triangle represents one of three required items you need to start and sustain any kind of fire.  They are:

  • Fuel - in the form of paper, wood, gasoline, plastic, oil, or other combustible material;
  • Heat - this could be a spark to get the fire going, or the heat generated when the fire becomes self-sustaining;
  • Air - an oxidant in the form of free oxygen in the surrounding environment, pressurized oxygen (stored under high pressure) or a chemical oxidant like you’d see in a roman candle or bottle rocket.

If you take away or interfere with any side of the triangle, you will successfully extinguish a fire EVERY TIME.  Interfere with more than one and you’ll extinguish it faster.  Early man used dirt (sand) and water to extinguish their campfire (a combination you’ll often find people using today when they’re camping recreationally and want to make sure their fire is really out before moving on).  Old-time fire engines (of the horse-drawn variety) used to carry sand in buckets attached to the sides for just this purpose (it also aided in preventing the engine’s horses from slipping on wet or icy roadways).

Fire extinguishers have been purposely designed to interfere with one (or more) side of our fire triangle.  Smaller extinguishers (the five and ten pound units most people are familiar with and see hanging everywhere) are designed to extinguish fires in the incipient stage (when the fire is small or has barely gotten started).

Extinguishers sold in North America are classified into several categories (called classes) depending on what kind of fuel is involved:



Common household items like wood, paper, cloth




Flammable liquids, plastics, solvents, and gasses




Energized electrical equipment and circuits (transformers, distribution panels, motors, small appliances, etc.)




Combustible metals like phosphorus, sodium, and powdered aluminium (often used in solid fuel rockets)



CLASS E (or K)

Cooking oils, kitchen grease, and fats



So, what makes up a modern extinguisher?

There are three common types of extinguishers in service today:


Cart Extinguisher

Cartridge based units (like the large wheeled unit to the left) utililze a high pressure nitrogen cylinder (the propellant) attached to a larger bottle which contains the agent.  Prior to use, you’re required to activate the the unit which causes the nitrogen to pressurize the larger bottle and then utilize the hose and nozzle to direct the agent at the base of the fire in broad sweeping motions.  These types of wheeled units often contain a special compound of potassium bicarbonate (known in the industry as Purple K) and the unit is classified BC (designed to extinguish both Class B and C type fires).  You’ll often see these units deployed on and around airport aprons in close proximity to parked aircraft.



Ansul K Class Extinguisher

Low pressure cylinders (the most common type seen today) employ a metal shell (usually spun aluminum or welded steel) which contains both the extinguishing agent and the propellant.  As you can see from the image to the left, it sports a convenient combination carry handle and actuator at the top.  To activate this unit, you need to pull the pin located just above the pressure gauge, aim the nozzle at the base of the fire, and depress the top lever while sweeping the nozzle from side to side to spread as much agent over the area as you can.  The cylinders come in a variety of finishes.  White, red, blue, and brushed (or polished) aluminum or steel.  Typical pressure in the cylinder ranges from 160 PSIG to 250 PSIG.  Depending on the agent used in the cylinder, the extinguisher can be rated as BC, ABC, D, or K.




High pressure cylinders employ a steel shell and utilize CO2 (Carbon Dioxide) as both the agent and propellant.  The CO2 cylinder doesn’t employ a gauge, so the only way to ensure the unit is fully charged is to weigh it.  Typical pressure in the cylinder is about 1800 PSIG.  The minimum full weight will always be shown on the label.  This type of extinguisher is rated BC.






What is a six year maintenance?
This is a special inspection which requires the extinguisher to be temporarily removed from service, discharged in a controlled environment (usually into a special powder recovery unit), and examined internally using a special bore scope camera and light.  The powder is examined for quality and evidence of moisture.  The extinguisher is then refilled using the same powder, and recharged.  Transport Canada and Warnock Hersey (the two agencies which certify Cylinder Requalifiers) then require a special tamper-proof label be affixed to the side of the cylinder which identifies the type of test performed, the name of the testing agency, and the name of the certified individual that conducted the maintenance procedure.

All internal cylinder examination (part of the six year maintenance procedure on dry powder extinguishers) MUST be performed by a registered Transport Canada or Warnock Hersey certified Cylinder Requalification Agency.

What is a hydrostatic test (also called a hydro-test)?
This is another special inspection performed every five (5) years on pressurized water, wet chemical and high pressure CO2 extinguishers, and every twelve (12) years on low pressure dry chemical extinguishers.  The units are temporarily removed from service and discharged.  In this case the agent is often not recovered (with the exception of CO2 which doesn’t degrade).  The unit is then completely dismantled and the cylinder is filled with water.  It’s connected to a special machine and lowered into a tank full of water.  Air, under pressure compresses the water in the cylinder to the manufacturer’s suggested test pressure and the cylinder’s expansion is measured against the manufacturer’s specified tolerances. The cylinder is kept under pressure for the required time to ensure any weakness in the welds or seams is exposed.  The cylinder is then removed from the tank, drained and put on a special drying rack.  It’s then refilled with fresh agent and recharged.  A special tamper proof label is affixed to the side of the cylinder in much the same fashion as a six year maintenance.  The label must identify the testing agency, the pressure to which the cylinder was exposed, and the name of the certified individual that conducted the test.  In the case of a CO2 cylinder, the test date and identifying mark of the certified testing agency is mechanically stamped into the neck (or skirt) of the bottle. 

All hydro-static testing MUST be performed by a registered Transport Canada or Warnock Hersey certified Cylinder Requalification Agency.

When should I use a fire extinguisher?
You should use it to aid in your escape from the immediate floor area or to try and control (or extinguish) a small fire and keep it from spreading.  The local fire department must be notified whenever an extinguisher is used on a fire in any building (even your home).  It’s often best to ensure an EXPERT assesses the situation to ensure the fire doesn’t re-flash.

How often must a fire extinguisher be inspected or checked?
This must be performed on a monthly basis and the details of any deficiencies have to be reported on a form that must be kept with the fire safety plan manual.  The Fire Prevention Office of your local fire department will likely send an officer around on an annual basis to check up on your building’s paperwork.  If you can’t document that you’re performing the monthly testing in accordance with the British Columbia Fire Code (2012) Division C, Clause, you could be hit with fines that escalate if the situation isn’t dealt with promptly.  Your extinguishers also have to undergo an annual inspection by a qualified technician in accordance with the requirements of NFPA 10 (2007) Standard for Portable Fire Extinguishers.

Can you tell us what a monthly inspection has to check?
Sure.  In the case of a dry chemical, low pressure extinguisher, you should check to make sure the seal holding the pull pin is in place.  If not, call for service.  If you handle the unit without the seal in place, you risk having the pin fall out which may lead to an inadvertent partial discharge.  And even if it’s only the briefest of activations, it’s enough to ensure that the valve won’t reseat properly, which will result in a slow leak to the point where the gauge falls below the normal operating range. 
Once you’ve ascertained that the safety pin is secure, remove the extinguisher from its wall hook (or cabinet), and examine it for obvious signs of damage (nicks, deep scratches, and dents).  Now invert the unit (hold it upside down) with the main body next to your ear.  You should hear the powder descend in one long smooth action.  If it falls in clumps, this may indicate that the powder is solidifying in the cylinder.  If you hear that, turn the extinguisher right-side-up for a few seconds then repeat the process while listening to the powder drop.  If it’s no longer falling in clumps, then you’re good to go (it means the unit’s been in one place for too long, or in the case of a vehicle mounted unit, the vibration has caused the powder to cake somewhat).  If the extinguisher is vehicle mounted, you should perform the “sound test” once a week to make sure the powder stays nice and loose in the cylinder.  Next, check the handle and operating lever for signs of damage.  Make sure the pin is straight and not bent where it emerges from the other side of the handle.  The pressure gauge should be in the GREEN operating range.  If you notice anything out-of-the-ordinary (or aren’t sure about something) call us!

NFPA 10 (2007) Sentence 4.4.1 requires all stored pressure extinguishers manufactured before October 1984 be removed from service at the next maintenance interval (six year or hydrostatic test).  Is there some sort of phased replacement we can implement in our building which has about twenty such units?
Sentence 4.4.1 is specifically EXCLUDED in the British Columbia Fire Code (2012).  There is no need to retire extinguishers of this age unless they become damaged or fail either the six year, or hydrostatic test.  You may want to discuss replacing older units anyway as they’re often more difficult to aim and control without the flexible hose new extinguishers are provided.






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