How Do Water Fire Extinguishers Work

Water fire extinguishers are commonly used to put out fires in Class A areas. However, it’s important to understand when and when not to use them, the places that need one, and how they work to fight flames. This guide has all the information you need.

What can water fire extinguishers be used on?

Water fire extinguishers are suitable for Class A fires, which involve flammable solids like paper, wood, and textiles. However, it’s crucial to remember that water fire extinguishers should never be used on electrical fires. Water conducts electricity and can cause electrocution. Additionally, they should not be used on Class B (flammable liquids), Class C (flammable gases), or Class F (cooking oil and grease) fires.

How do water fire extinguishers work?

Water has a cooling effect on the fire, which reduces its temperature and stops it from burning. This eventually puts out the flames. Water fire extinguishers have a spray nozzle instead of a jet nozzle, allowing the water to cover a larger area and extinguish the fire quickly.

How are water fire extinguishers identified?

The canister of a water fire extinguisher has a label on the top that says ‘Water’ in white color. Right above it, there should be a sign indicating the type of fire extinguisher and the classes of fire it can and cannot be used on. See how many fire extinguishers are required in a business premises.

Where are water fire extinguishers most suitable for use?

Water fire extinguishers are often needed in buildings constructed with wood or organic materials, as well as in places that store a significant amount of these flammable substances. Hospitals, schools, and offices would find it beneficial to have a water fire extinguisher available, along with warehouses and storage units. See when should fire extinguisher be visually checked.

Parts of a Water Fire Extinguisher

Just like all fire extinguishers, there is a seal called a tamper seal that goes around the ring or pin on the handle. This seal is in place to prevent the fire extinguisher from being accidentally discharged. Inspectors check the tamper seal to see if the extinguisher has been used. If the seal is broken or missing, the inspector will know that the extinguisher needs to be inspected and possibly serviced.

Inside the cylindrical tank made of steel, there is a canister that holds high-pressure gas. The rest of the extinguisher is filled with water. Inside the tank, there is a long tube that runs vertically and connects with the valve assembly. This tube leads to the nozzle on the outside, where the water is expelled to put out the fire.

To find out more about the different parts of a fire extinguisher, you can read our other article called “Parts and Components of a Fire Extinguisher.”

How to Operate a Water Fire Extinguisher

Using a fire extinguisher may seem simple and straightforward, but people often panic when faced with a fire at home or in the workplace. As a result, they tend to spray the extinguishing agent in an ineffective manner, which fails to put out the fire.

To address this, the acronym P.A.S.S. was developed to help individuals remember the proper use of a fire extinguisher. The steps for operating a water fire extinguisher are the same as for any other type. They are as follows:

1. Pull the pin
2. Aim low at the base of the fire
3. Squeeze the lever
4. Sweep from side to side

By following these straightforward steps during a fire emergency, you will be more effective in combating the fire.

For more information about the P.A.S.S. technique, please read our article titled “How to Operate a Fire Extinguisher.”

For What Class of Fire is a Water Extinguishers Used?

The fundamental chemical reaction for fire remains the same: Oxygen + Heat + Fuel = Fire. However, each type of fire has its own distinct characteristics and fuel source, which means you need a fire extinguisher specifically designed to put out that particular type of fire.

Water extinguishers are suitable for Class A Fires, which involve combustible materials like wood, paper, cloth, trash, and plastics. They work by removing the heat from the fire. When the heat is taken away, the chemical reaction required for fire is no longer sustained, leading to the extinguishing of the fire.

Which Fire Extinguisher Should I Purchase?

When purchasing a fire extinguisher, there are several factors to consider. Water fire extinguishers are just one type among various options. The main types of fire extinguishers include Class ABC, Class K, Class Purple K, Halotron, Carbon Dioxide, Water, and Foam.

To determine the most suitable fire extinguisher for your needs, consider the following questions:

1. Where will the fire extinguisher be used? (Commercial or Residential)

In the workplace, fire extinguishers must meet specific OSHA standards in terms of size, extinguishing agent, and proper placement with appropriate signs. Home fire extinguishers are not subject to OSHA guidelines and regulations.

2. If a fire were to break out, what would be its fuel source? (wood, paper, oil, gas, grease, or electrical)

Identify the potential fuel sources for fires in the intended area. For example, electrical fires may occur in computer server rooms, while oil or grease fires are common in large industrial kitchens. Home fires can have various fuel sources, such as wood/paper, electrical, or cooking grease. In such cases, a Class ABC fire extinguisher can effectively handle all three types of fires.

3. How large of an area needs to be covered? (small or large room, home kitchen, or large storage unit)

Consider the size of the area where the fire extinguisher will be used. For instance, using a small 5-pound extinguisher in a large 3,000 sq ft warehouse may not be sufficient, while a large 150-pound wheeled extinguisher may be excessive for a home kitchen. Understanding the space requirements is crucial, as different extinguishers have varying coverage capacities.

4. Who will be using the fire extinguisher? (elderly individuals, children, men, or women)

Take into account the individuals who may need to use the fire extinguisher. Consider their capabilities and strength when handling different extinguisher weights. It’s important to choose a fire extinguisher that can be effectively used by the intended users.

Considering these factors will help you make an informed decision when selecting a fire extinguisher that suits your specific requirements.

When Should You Not Use Water Fire Extinguishers?

Using a water fire extinguisher on a Class B fire (involving flammable liquids or gases, such as paint, propane, or butane) can be dangerous. The force of the discharge from the extinguisher can spread the flammable liquid or gas, causing the fire to grow instead of extinguishing it. When water hits burning oil, it displaces the oil and scatters burning drops, leading to the rapid spread of the fire. To effectively tackle a Class B fire, it is best to use ABC, Halotron, or Purple K fire extinguishers.

Water fire extinguishers are not suitable for Class C fires (involving electrical equipment like motors or kitchen appliances) because water conducts electricity. Attempting to use water on an electrical fire can result in electric shocks, which can cause injury or even death. ABC, Carbon Dioxide, or Purple K fire extinguishers are the recommended types for dealing with electrical fires.

Water fire extinguishers are highly effective and easy to use for Class A fires. However, when purchasing a fire extinguisher for your home, office, or warehouse, it is essential to consider various factors to ensure the safety of yourself and others when using the extinguisher for the specific type of fire it will be dealing with.