Get to Know Your Fire Extinguishers: Fire Extinguisher Parts & Usage

Posted September 08, 2020 by Koorsen Fire & Security

fire extinguisher valve stems

Fire extinguishers – they are everywhere.

You’ll find them in every place of business, nearly every place of residence, and even in many people’s cars.

Yet, while their presence is ubiquitous, knowledge of how they work and how to use them is not as common. Simply knowing where one is will not help you safely put out a fire. You need to know the parts of a fire extinguisher and how they work.

To that end, this post will provide basic information about the parts of your fire extinguisher and how they work so that, should you ever have the need, you will be ready to use it.

The Parts of a Fire Extinguisher                 

While there are many different types of fire extinguishers – water, dry chemical, foam, clean agent, etc. – for the most part, they have the same or very similar parts with which to operate them.

In general, regardless of the class of extinguisher and the type of extinguishing agent they may contain, you can expect a fire extinguisher to have a:

  • Cylindrical Tank
  • Valve
  • Carry Handle
  • Operating Lever
  • Pull Pin
  • Tamper Seal
  • Pressure Gauge
  • Discharge Hose
  • Discharge Nozzle
  • Instruction Label
  • Monthly inspection tag
  • Annual inspection tag
  • Extinguishing Agent and Propellant

Each of these parts has a vital role to play, and some work together to perform one main function of the extinguisher.

The Role of Each Part

While there are many separate parts, each part contributes to one of three main roles: storing, expelling, or informing.

  • Cylindrical tank: the tank of any fire extinguisher is responsible for storing the extinguishing agent and the propellant under the correct amount of pressure. Typically made of steel, even small tanks can be surprisingly heavy.

The parts of the fire extinguisher responsible for the act of expelling the extinguishing agent together are known as the Valve Assembly. These parts include the:

  • Valve: responsible for controlling the flow of the agent, the valve is the mechanism connecting the carry handle and the operating lever and around which they function.
  • Carry Handle: simply that, the handle allows for easy grasping, lifting, and carrying of the extinguisher.
  • Operating lever: the lever is the metal piece that can be pressed or squeezed to operate the extinguisher. However, the operating lever will not be able to be pressed/squeezed unless the pull pin has first been removed.
  • Pull pin: also known as the locking pin, this metal pin is inserted into the valve portion of the fire extinguisher and prevents accidental discharge (for instance, accidentally squeezing the operating lever down when you only meant to carry the extinguisher to a different location).
  • Tamper seal: a plastic tamper seal is placed to keep the pull pin from falling out accidentally.
  • Pressure gauge: the pressure gauge is a small, circular gauge attached to the outside of the valve assembly to show whether or not the fire extinguisher has proper pressure to expel the agent in the event of a fire. If the arrow of the gauge is in the green, it is properly charged. If it is to the left of the green, it is undercharged and will not have enough pressure to work properly. If the gauge needle is to the right of the green, it is overcharged and is a hazard at risk of exploding. C02 extinguishers do not have pressure gauges.
  • Discharge hose: the discharge hose is the hose that allows the extinguishing agent to travel from the tank to the base of the fire and enables the user to aim the flow of the agent.
  • Discharge nozzle: the nozzle is the hose’s conical end, out of which the extinguishing agent disperses.

In addition to these functioning elements of the fire extinguisher, there is also the informative parts, which include:

  • Instruction label: all properly operating fire extinguishers should have a legible instruction label on the extinguisher’s tank that provides instructions for proper use & which type of fire it is intended to be used on.
  • Monthly inspection tag: this tag allows the owner or person responsible for the monthly inspection to record the date of the monthly check as well as the initials of the individual who inspected it. This tag helps prove compliance with your local AHJ, as these monthly inspections are required.
  • Annual inspection tag: this tag is where your professional fire and security provider, such as Koorsen, will record the date and essential information behind the required annual maintenance inspection. This tag will be useful in proving compliance with local codes and in ensuring that the extinguisher is receiving the proper care that it needs to operate correctly when needed.

And of course, a fire extinguisher would not be such if it were not for the extinguishing agent – the chemical and/or substance stored inside the tank capable of suppressing or extinguishing a fire – and the propellant – the gas responsible for expelling the extinguishing agent out of the tank when activated.

Rules for Safe Use

When choosing to use a fire extinguisher to fight a fire, remember first to check that it is the correct class for the fire you are fighting (only a Class A rated extinguisher can be used when ordinary combustibles are involved, only a Class B rated extinguisher can be used when flammable liquids are involved, and only a Class C rated extinguisher can be used when electrical equipment is involved).

If you have the correct extinguisher, then just remember PASS:

  • Pull the pin
  • Aim the nozzle at the base of the fire from a safe distance
  • Squeeze the lever to discharge the agent
  • Sweep the hose from side to side

If you are in danger of being overwhelmed by the fire or trapped, it is best to evacuate the building and leave fighting the fire to emergency responders.

Need More Training?

For many, hands-on practice will go much further in preparing them to be ready to help fight a fire should the need occur.

Fortunately, there are opportunities to get hands-on practice and training. If you call Koorsen Fire & Security, one of their expert instructors can come to your business to provide one-of-a-kind training so that your team is prepared to respond quickly, correctly & safely in the event of a fire.

Furthermore, Koorsen is ready to help you in selecting the best extinguishers for your business and staying up to code with maintenance and inspection requirements.

Don’t hope that your team and fire extinguishers are up to the task in the event of a fire. Instead, be confident that your people and property are safe by calling Koorsen today to arrange training and proper maintenance.

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Topics: Fire Protection, Fire Extinguisher, Fire Training, Inspection/Testing

Disclaimer: The information in this article is for informational purposes only. It is believed to be reliable, but Koorsen Fire & Security assumes no responsibility or liability for any errors or omissions in the content of this article. It does not constitute professional advice. The user of this article or the product(s) is responsible for verifying the information's accuracy from all available sources, including the product manufacturer. The authority having jurisdiction should be contacted for code interpretations.