Size: DN25~DN600

Pressure range: 0.25-5.0Mpa

Material: Carbon steel, 304, 316L stainless steel

Flame retardant core: 304, 316L stainless steel corrugated plate

Explosion proof level: IIA, IIB, IIC

Flange standard: HG20592-97 PN1.0 (customizable)

Surface treatment: SY7511-87 and API2000

Breathing manhole is a safety emergency ventilation device installed on a storage tank of petroleum, chemical and other materials. It is usually used together with the fire-retardant breathing valve, which can not only avoid the accident caused by sudden overpressure or vacuum in the tank caused accident, but also play a role of safety fire-retardant. It is an ideal device to protect the safety of tanks in China.