Breathing valve is fixed at the top of tank ventilation devices to ensure that the tank pressure normal. Tank prevents overpressure or vacuum tank so that suffered damage, but also reducing the loss of volatile liquid storage tank.

According to the "Petrochemical design of fire safety regulations" (GB50160-92) states : "A B liquid fixed roof tanks, should be established and the two semi-breathing valve, "Hichine company developed HB-type series of new products, complete with specifications, compact, light weight, the ventilation, leaking small advantages. Products are called single valve, single-suction valve, breathing valve structures can form combinations with fire retardant structure, also preparation for the takeover

Working media :

Gasoline, kerosene, diesel oil, aromatics, sulfur, air, oil or other chemical materials. Selection of fire retardant under the category "HGJ21-89".

Operating pressure and the use of ambient temperature:

Expiratory pressure : B, C +980Pa, +1750Pa D, E +4KPa, +18KPa
Suction pressure : B, C -295Pa, -295Pa D, -0.5KPa
(Operation pressure indicators can be specified by the user)

environmental temperature : -30 ° C -60 ° C