HXF2 with a double to take over breathing valve in accordance with the provisions of "fire protection design of petrochemical enterprises" (GB50160-92) of national standards: "A and B liquid fixed roof tanks, flame arrester should be located and breathing valve." Visible breathing valve, flame arrester is indispensable tank safety. It can not only maintain the pressure balance tank, make sure the tank from damage during over-pressure or vacuum, and can reduce evaporation and loss of the tank medium. Hatch high-valve plant breathing valve, with a compact, ventilation volume, leakage, good sealing performance characteristics. The main parts materials Body material carbon steel WCB, 304,316 stainless steel, aluminum positive pressure valve plate material stainless steel 304, aluminum vacuum valve plate material stainless steel 304, PTFE PTFE Ambient temperature ℃ -30 ~ 60 The main external connection size DN 50 80 100 150 200 250 H 280 430 430 530 630 740 H1 110 180 180 220 260 320 L 310 450 450 650 850 1000