Brief Introduction of Breathing Valve
The breathing valve is an equipment that not only ensures that the storage tank space is isolated from the atmosphere within a certain pressure range, but also can communicate with the atmosphere when exceeding or below this pressure range. Its function is to prevent the tank from being damaged by over pressure or vacuum, and at the same time reduce the evaporation loss of the storage liquid. The setting can not only reduce the gas emission in the tank, thereby reducing the pollution to the atmosphere, but also prevent the tank from being damaged by over pressure or destabilized by ultra-vacuum, which plays a certain role in promoting safety and environmental protection.
It is mainly composed of a seat, a cover, a protective cover and two groups of opening and closing devices controlled by vacuum and pressure. The opening and closing device comprises a valve disc, a guide rod, a spring, a spring seat and a sealing ring, etc. When the pressure in the tank reaches the rated positive exhaled pressure, the pressure valve flap opens and the steam in the tank is discharged; When the vacuum degree in the tank reaches the rated suction negative pressure, the vacuum valve flap opens and the air enters.
The working principle
- When the pressure of the medium in the tank is within the control operating pressure range of the breathing valve.It does not work to maintain the tightness of the oil tank;
- When the medium is added to the tank to increase the pressure of the upper gas .The space in the tank and reach the operating positive pressure .The pressure valve is pushed open and the gas escapes from the breathing valve outlet, so that the pressure in the tank does not continue to increase;
- The atmosphere outside the tank will push open the negative pressure valve disc of the breathing valve.
The role of the breathing valve
The breathing valve is a safe and energy-saving product to maintain the pressure balance of the storage tank and reduce the volatilization of the medium. The breathing valve makes full use of the pressure capacity of the storage tank itself to reduce the emission of the medium.
The principle is to use the weight of the positive and negative pressure valve disc to control the positive pressure of the exhaust and negative pressure of the storage tank. When the medium is pumped out of the tank to reduce the pressure of the upper gas space in the tank and reach the operating negative pressure of the breathing valve, the atmosphere outside the tank will top open the negative pressure valve disc, so that the outside gas enters the tank, so that the pressure in the tank will no longer continue to fall, so that the pressure balance between the tank and the tank outside the tank to protect the safety device of the storage tank.
The specific function
The breathing valve seals under normal conditions to prevent the leakage of gas in the tank, and only begins to work under the following conditions.
- When the storage tank outputs the material outward, then it begins to inhale air into the tank.
- When the material is filled into the tank, it will begin to exhale the gas inside the tank.
- Due to climate change and other reasons caused by the material in the tank steam pressure increased or reduced breathing valve, exhaled steam or inhaled air or nitrogen known as thermal effect.
- In the event of a fire, the evaporation of the liquid in the tank is greatly increased due to heat, and the breathing valve begins to exhale out of the tank to avoid damage due to over pressure.
- In other working conditions, such as pressurized transportation of volatile liquids, chemical reactions of internal and external heat transfer devices, operation errors, etc., the breathing valve is exhaled or inhaled to avoid damage to the storage tank due to over pressure or ultra-vacuum.
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