Which of the following is a common sign that a Class K extinguisher needs service?

• A. The unit is cold to the touch
• B. No visible corrosion
• C. Loss of pressure
• D. The gauge shows full pressure

Answer: (C)

Loss of pressure is the clearest sign that a Class K extinguisher needs service because these units rely on stored pressure to expel the wet chemical agent when discharged. If the pressure drops, the extinguisher may not release enough agent or any at all, making it unreliable in an emergency. A gauge reading full pressure means it’s charged and ready, while a cold unit or the absence of visible corrosion aren’t dependable indicators of functional readiness. So when the pressure is lost, servicing and recharging are required to ensure proper operation.