ZHXRK type double drawer fire-resistant breathing manholeDetailed product description：

ZHXRK type double drawer fire-resistant breathing manhole technology performance

1. Operating pressure Positive pressure:+1765Pa180mmH2O Negative pressure: -392Pa-40mmH2O
2. Fire resistance level: BS 5501: IIA standard 3. Operating temperature:+60 ℃~30 ℃
3. Scope of application: Especially suitable for storing materials in dome shaped atmospheric pressure tanks capped with nitrogen gas

Working Principle
Under normal working conditions of flame retardant breathing, the flame retardant breathing manhole is basically sealed, and the storage tank is at normal pressure. When the normal operation of the breathing valve cannot meet the sudden overpressure of the storage tank caused by unexpected reasons, the relief cover of the breathing manhole will automatically open for emergency pressure relief to maintain the normal pressure inside the tank; When the pressure inside the tank drops sharply or exceeds the vacuum, the suction valve opens to rapidly suck in the atmosphere, maintaining the normal pressure inside the tank; When there are sparks or fire traps in the atmosphere, the fire barrier layer plays a role in the "wall effect" to prevent the passage of fire traps and protect the safety of the storage tank.

Model meaning: