Dry Powder (Class D Fires)
MET-L-X POWDER (SODIUM CHLORIDE) FIRE EXTINGUISHERS
Use for Class D Fires
What type of fires can be extinguished with a MET-L-X powder extinguisher?
Class D fires only involving combustible metals - magnesium, sodium (spills and in depth), potassium, sodium-potassium alloys uranium and powdered aluminum.
What is the proper way to use a Class D, sodium chloride extinguisher?
Pull the pin. Holding the extinguisher with the nozzle pointing away from you, pull out the pin located below the trigger. Note: Lifting the extinguisher by the handle will not activate the extinguisher.
Hold nozzle over fire. The 6 foot reach of the extension appicator hose and the squeeze grip valve allows placement of the dry powder exactly where it will be most effective. Remember - extinguishers are designed to be operated in an upright position. Always hold the extinguisher vertically. Never cradle it horizontally or at an angle in your arms. If the extinguisher is too heavy to hold properly, place on the floor next to you and operate.
Squeeze the discharge lever. Squeeze slowly and evenly. This action will release the dry chemical and expel it through the discharge nozzle.
Apply the dry powder. Completely cover the burning metal with a thin layer of powder. Once control is established, take a position that is in close range. Throttle the stream with the nozzle valve to produce a soft, heavy flow. Cover the metal completely with a heavy layer of powder. Be careful not to break the crust formed by the powder. Slowly open the nozzle of the extinguisher.
Once activated, can the extinguisher be turned off?
Yes, stop squeezing the trigger and the dry powder will be turned off. In fact it may be best to do this while repositioning yourself in relation to the fire when necessary.
How far will the dry powder stream reach?
With the nozzle fully opened, the horizontal range of the dry powder stream will reach a distance from 6 to 8 feet.
How long will it take to use up the 30 pounds of dry powder in the extinguisher?
The approximate time to discharge the 30 pounds of dry powder is 28 seconds.
How does the sodium chloride dry powder put out a fire?
The heat of the fire causes the dry powder to cake and form an exterior crust. This crust excludes air and results in extinguishment. It also dissipates the heat from the burning metal.
What are the advantages and disadvantages of the sodium chloride dry powder?
The extinguishers are very heavy - an extinguisher containing 30 pounds of powder weighs 53 pounds. Application of the dry powder on Class A, B or C fires can be very dangerous.
