overview

The HXF-2 with dual pipe flame retardant breathing valve is a ventilation device fixed on the top tank. To ensure the normal pressure inside the tank, prevent damage to the storage tank caused by overpressure or vacuum, reduce oil evaporation loss, control tank pressure, and prevent external flames from entering. The HXF-2 dual tube breathing valve has the advantages of multiple types, complete specifications, compact structure, light weight, large ventilation capacity, and small leakage. Suitable for storing Class A oil products with a flash point below 28 ℃ and Class B oil products with a flash point below 60 ℃, such as gasoline, benzene, kerosene, light diesel, thick oil, and chemical product storage tanks with the same properties.

Structural characteristics

The HXF-2 dual tube flame retardant breathing valve consists of a pressure valve and a vacuum valve. The valve body of this valve can withstand a water pressure of 0.2Mpa without any leakage or deformation. There is sufficient space inside the valve body to ensure the ventilation of the storage tank. When the valve disc component operates, it has high sensitivity and ensures sealing after the operation is completed. When the relative humidity of the air is greater than 70% and the low temperature is -30 ℃, after 24 hours of freezing, the valve disc opening pressure meets the working pressure requirements (allowing a pressure difference of plus or minus 20pa). The HXF equipped breathing valve has an electrostatic grounding wire to maintain an equipotential between the valve and the tank body. At present, technical improvements have been made to the parts of the takeover breathing valve that are prone to static electricity, and PTFE gaskets have been added to eliminate the need for static discharge devices. The HXF with a connecting breathing valve can automatically regulate and balance the pressure inside and outside the oil tank, providing safety for the oil tank. This valve can automatically adjust the pressure difference inside and outside the oil storage tank, and its performance is reliable and stable, fully complying with the SY7511-87 standard of the Ministry of Petroleum Industry.

Working principle

When the oil and gas pressure inside the tank exceeds the allowable pressure of the oil tank, the oil vapor escapes through the pressure valve, and the vacuum valve is in the closed state; When the oil and gas pressure inside the tank is lower than the allowable vacuum degree of the oil tank, fresh air enters the tank through the vacuum valve, and the pressure valve is in the closed state. The allowable pressure (or vacuum pressure) is controlled by the weight of the regulating plate. The principle of fully utilizing the pressure bearing capacity of the oil tank itself to reduce oil vapor emissions is to use the weight of the valve disc to control the positive exhalation pressure and negative inhalation pressure of the oil tank. When the pressure of the gas inside the tank is within the control pressure range of the mechanical breathing valve, the breathing valve does not operate, maintaining the airtightness of the oil tank; When the pressure in the gas space inside the tank increases and reaches the control positive pressure of the breathing valve, the pressure valve is pushed open, and gas escapes from the tank, preventing the pressure inside the tank from continuing to increase; When the pressure in the gas space inside the tank drops and reaches the negative pressure controlled by the breathing valve, the atmosphere outside the tank will open the vacuum valve and enter the tank, preventing the pressure inside the tank from continuing to decrease.

Maintenance and upkeep

In order to ensure the safe use of the dual tube breathing valve, the flame retardant breathing valve should be regularly inspected and maintained:

1. Check whether the pressure valve disc and vacuum valve disc operate flexibly, and whether the contact surface of the guide rod and valve sealing ring is damaged.

2. When reinstalling the pressure plate and vacuum plate, ensure that the contact surface is tight and the guide rod can be raised and lowered flexibly.

3. When activating a new breathing valve, the shock absorber on the disc must be removed.