Part Description:

1. Limiting sleeve rod 2. Outlet connection flange 3. Positive pressure valve rod disk 4. Positive pressure valve seat 5. Valve body 6. Storage tank connection flange 7. Dust cover 8. Negative pressure valve seat 9. Negative pressure valve rod disk 10. Valve cover

I. Product Introduction

The AD1220 type call-out take-off breathing valve is a safety device for the top of atmospheric storage tanks, which maintains the pressure in the tanks at a normal level, reducing the evaporation loss of volatile liquids inside the atmospheric storage tanks, and protecting the tanks from damage due to overpressure or vacuum.

The AD1220 type exhaust valve with call-out conduit is a new type of breathing valve designed for conditions where the stored medium is toxic and polluting. It features the ability to discharge exhaust gases into the recovery pipeline.

Compared to commonly used breathing valves in China, these have a larger air volume, operate as separate valve cavities under overpressure and negative vacuum, offering better stability, and are frequently used in large-scale storage and transportation projects.

Section II: Working Principle

The AD1220 type exhaust gas recovery valve is installed at the top of the storage tank or equipment, which not only maintains the pressure balance of the tank to prevent damage during overpressure and vacuum conditions, but also reduces oxidation and loss of the medium inside the tank.

When the internal pressure of the canister falls below the negative vacuum setting pressure of the breathing valve, atmospheric pressure opens the vacuum valve disk, replenishing air into the canister to prevent the pressure from dropping further, thus avoiding the collapse of the storage tank or equipment.

When the pressure inside the tank exceeds the exhaust pressure setting of the breathing valve, the pressure valve is lifted by the gas, allowing gas to escape from the tank, thereby preventing the pressure from rising further inside the tank.

Section 3: Pressure Setting Range Activation

SY/T0511.1-2010----Section 1 of "Petroleum Storage Tank Accessories – Part 1: Breathing Valve" specifies the opening pressure of the breathing valve for atmospheric (including internal vacuum) petroleum storage tanks as follows:

The 5 grades required by SY/T0511.1-2010 all feature a gravity-assisted opening method for the breathing valves.

In 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 and operating conditions provided by the customer.

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 disc structure and imported FEP diaphragm technology, achieves 10% overpressure technology.

4. FEP film sheets feature resistance to chemical corrosion, adhesion of liquids and steam, extreme temperature, and bonding due to valve seat freezing.

5. Prior to shipment, each unit undergoes testing of the opening pressure and leakage amount on the pressure test platform. Upon passing the inspection, they are then released for production.

6. Carbon steel valve bodies are coated with anti-rust primer both inside and out, with an epoxy topcoat applied on the exterior; stainless steel valve bodies are sandblasted; plastic valve bodies are polished.

7. Packaging is uniformly done in standard wooden crates.

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 Industry Storage & Transportation System Tank Farm Design Specification

• GB50160-2018——Standard for Fire Prevention in Design of Petroleum and Chemical Enterprises