1. Introduction of product: Breather manhole (emergency vent manhole) (LFH-R500/600) is a
safety emergency ventilation device installed in the oil and chemical storage tank, usually with the same installation of tank top supporting the use of breather valve. It will maintain the normal pressure in the tank, which can avoid by accident tank sharp overpressure or vacuum tank, damage and accident; It is with some advantages of constant pressure discharge, the constant pressure closed suction, the advantages of flexible, safe fire retardant, compact structure, good sealing performance, safety and reliability etc.
2. Main technical parameters:
A. Working pressure: breathe out: +1961.2(200mmH2O)
                     Suction: -392.2(-40mmH2O)
B. Temperature range: -30-60℃
C. Suction area: 0.043116M2
D. Type: DN500 （￠705×H380）
          DN600 （￠805×H480）
3. Product picture: