The single breathing valve makes full use of the pressure bearing capacity of the oil tank to reduce the oil vapor emission. Its principle is to use the weight of the valve disc to control the positive expiratory pressure and negative suction pressure of the oil tank. When the pressure of the gas in the tank is within the control pressure range of the mechanical breathing valve, the breathing valve does not act to maintain the tightness of the oil tank; when the pressure of the gas space in the tank increases to reach the control positive pressure of the breathing valve, the pressure valve is jacked open, and the gas escapes from the tank, so that the pressure in the tank does not continue to rise; when the pressure of the gas space in the tank drops, the control negative pressure of the breathing valve is reached The atmosphere outside the tank will open the vacuum valve and enter the tank, so that the pressure inside the tank will not continue.
The single breathing valve is a control component in the fluid conveying system, which has the functions of cut-off, regulation, diversion, prevention of countercurrent, pressure stabilization, shunt or overflow pressure relief. The shape of the breathing valve is irregular, and the traditional thermal insulation material is particularly difficult to construct.
