
Component Description:
1. Valve cover 2. Fasteners 3. Gasket 4. Negative pressure valve rod disk 5. Negative pressure valve seat 6. Positive pressure valve rod disk 7. Negative vacuum intake 8. Valve body 9. Connecting flange 10. Positive pressure valve seat 11. Overpressure exhaust outlet
I. Product Introduction
The ADHXF-II type dual outlet breathing valve is a safety device installed on the top of atmospheric storage tanks. It maintains the pressure inside the tank at a normal level, reducing the evaporation loss of volatile liquids within the tank, and protecting it from damage due to overpressure or vacuum.
The ADHXF-II type dual outlet breathing valve is designed for storage tank conditions where the medium is toxic, polluted, and reactive with air. It features the ability to exhaust gases into the recovery pipeline, and can also be connected to a nitrogen pipeline to intake nitrogen to compensate for pressure loss in the storage tank.
2. Working Principle
The ADHXF-II type with dual exhaust valve is installed on the top of tanks or equipment, which not only maintains the pressure balance of the tank, ensuring it is protected from damage under overpressure and vacuum conditions; but also reduces oxidation and loss of the medium inside the tank.
When the internal pressure of the tank is low and the breathing valve's negative vacuum set pressure is reached, the nitrogen being introduced will lift the vacuum valve disk, replenishing nitrogen into the tank to prevent the pressure from dropping further, thus avoiding the collapse of the storage tank or equipment.
When the pressure inside the can exceeds the exhaust pressure setting of the breathing valve, the pressure valve is lifted by the gas, allowing gas to escape from the can, preventing the pressure inside from rising further.

Section 3: Pressure Setting Range Activation
SY/T0511.1-2010 -- Section 1 of "Petroleum Storage Tank Accessories: Part 1 - Breathing Valves" specifies the opening pressure for breathing valves for atmospheric (including internal vacuum) storage tanks.

The 5 grades required by SY/T0511.1-2010 all feature a gravity-assisted opening method for the breath valves.
In the API 2000, the typical set pressure range for gravity breathing valves is -4.3 KPa to +6.9 KPa, while the set pressure for spring-loaded breathing valves must exceed this range.
Section 4: Product Advantages
1. Provide professional breathing valve calculation sheets and CAD drawings based on the data table provided by the customer and the operating conditions.
2. Eddie summarizes years of design and manufacturing experience, optimizing the sealing form of the breathing valve, sealing materials, pressure set points, flow coefficients, and return seat sealing. As a result, the breathing valve achieves zero-leakage sealing effect at 80% of the set pressure.
3. Utilizing a tower-type valve disk structure and imported FEP diaphragm technology, achieving a 10% overpressure technology.
4. FEP film sheets feature resistance to chemical corrosion, adhesion of liquids and vapors, extreme temperature, and bonding caused by valve seat freezing.
5. Prior to shipment, each unit undergoes testing of opening pressure and leakage rate on a pressure testing platform. Units that pass the test are then released for shipment.
6. Carbon steel valve bodies are coated with anti-rust primer inside and out, with an epoxy topcoat applied; stainless steel valve bodies are sandblasted; plastic valve bodies are polished.
7. Standard wooden boxes are used for uniform packaging.
V. Relevant Standards for the Product
• API 2000-2014 ------ Ventilation Atmosphere and Low-Pressure Storage Tanks
• SY/T0511.1-2010----"Petroleum Storage Tank Accessories - Part 1: Breathing Valve"
• SH/T3007-2014——Petroleum & Chemical Storage and Transportation System Tank Farm Design Specification
• GB50160-2018 -- Design Fire Protection Standard for Petroleum & Chemical Industry Enterprises






























