HDT Global

HDT’s M20 Protective Entrance is a transition enclosure and protected entryway. It is used as an air lock to protect the shelter interior and also provides a clean air “shower” to help decontaminate personnel entering shelters. Personnel pause for a specified period of time before entering a shelter to allow the purging of airborne contaminants introduced by opening the outer door.

• The M20 prevents direct vapor transport into the enclosure and ensures that internal pressure is maintained continuously in the enclosure while entries and exits occur. The air lock is purged by the flow of clean air from the main protected enclosure, through the air lock and out a discharge vent on the outer air lock door.
• Personnel entry and exit is an important consideration for military collective protection shelters. Consideration needs to be given to both hardware (ventilated air locks) and procedures for transitioning from individual protection to collective protection.
• HDT’s M20 Protective Entrance can provide the benefit of helping to maintain pressures within a protected area to ensure continuous protection during routine operations

Benefits of the M20 Protective Entrance include:

• Lighting and controls are powered by the shelter
• Airflow is from the shelter filtration system
• The air lock occupies no internal space and is self-supported when erected
• Normal shelter door usage is unaffected