Amerex Moisture Seal 07411 - OEM

The Amerex 07411 Moisture Seal is a factory replacement component for 300 and 350-lb Amerex wheeled or stationary dry chemical fire extinguishers. It is installed in the hose coupling to keep moisture out and maintain pressure integrity in the extinguisher assembly. In plain terms: dry chemical agents like ABC powder and Purple K are hygroscopic — they absorb moisture from the air. If moisture gets into the hose coupling, it can cause the dry chemical agent to clump or cake inside the hose, blocking agent flow during an emergency discharge. The 07411 moisture seal prevents this by creating a barrier at the coupling that keeps humid air from reaching the agent.

This is a critical part for service and recharge procedures on 300 and 350-lb Amerex wheeled extinguishers. These large-capacity units are commonly deployed at industrial facilities, aircraft hangars, fuel storage areas, and other high-hazard locations where their large agent capacity is needed to fight bigger fires. A moisture-clogged hose on a 300-lb unit is a very different problem than on a small portable — if the hose blocks during discharge, a significant fire hazard loses its primary suppression response. Replacing the 07411 moisture seal at every internal examination is cheap insurance against that failure scenario.

The 07411 is an Amerex OEM part listed in the Amerex fire extinguisher parts catalog for compatible wheeled and stationary units. Available through authorized Amerex distributors. Replace the moisture seal at every 6-year internal examination per NFPA 10, and after any discharge event. Document the replacement on the fire extinguisher inspection and maintenance tags.

Replace the 07411 moisture seal at every 6-year internal examination of the compatible wheeled extinguisher per NFPA 10. During the internal exam, the technician will disassemble the hose coupling, inspect the interior for moisture damage or caked agent, replace the moisture seal with a new 07411, and reassemble. If any agent caking is found inside the hose, the hose must be cleaned or replaced before the unit is recharged and returned to service. Document the moisture seal replacement on the fire extinguisher inspection and maintenance tags. Also replace after any discharge event before the unit is recharged.

How do I know if moisture has gotten into my wheeled extinguisher hose?

The most common sign is a partial or complete blockage during discharge — if the agent comes out in clumps or doesn't come out at all, caked agent from moisture absorption is the likely culprit. During annual NFPA 10 inspections, the technician may also feel a hose that seems stiffer or more rigid than normal, which can indicate agent caking inside. The moisture seal and hose assembly should be inspected at every annual visit. If the extinguisher is stored in a high-humidity environment, the moisture seal is especially important.