Hubei Wan'an Environmental Protection - Breathing Valve

• Model: HXF-QZ
 
• Origin: Hubei
 
• Product Overview: The breathing valve is a pressure protection device installed on the top of the tank area to ensure the balance of pressure inside and outside the tank, prevent overpressure or direct air damage inside the tank, and reduce the evaporation loss of liquid inside the tank.
 
• Customized consultation: 027-81948788
 
• Product type: Integrated flame retardant breathing valve, single breathing valve, jacketed single breathing valve, jacketed breathing valve

1. Overview

A breathing valve is a pressure protection device installed on the top of a storage tank in the tank area to ensure the balance of pressure inside and outside the tank, prevent overpressure or vacuum damage inside the tank, and reduce the evaporation loss of liquid inside the tank.

According to the Chinese "Fire Protection Design Code for Petrochemical Industry", "Fixed top tanks for Class A and Class B liquids should be equipped with flame arresters and breathing valves". However, the types of breathing valve products in our country are single and cannot meet the needs of various tank areas in the petrochemical industry. Our company has developed the API 2000 series breathing valve and emergency relief valve products. The product has the advantages of complete specifications and varieties, large ventilation capacity, and good sealing performance. The product types include exhaust breathing valves, breathing valves with connecting pipes, single breathing valves, single suction valves, etc. According to different pressures, it can be divided into gravity load type and spring load type. Each specification of breathing valve can be used in conjunction with flame arresters.

2. Functional Features

 Most storage tanks are equipped with breathing valves, emergency relief valves (or emergency relief manholes), gas regulating valves, flame arresters, and other devices.

 The breathing valve can provide pressure or vacuum relief under the conditions of pump injection/extraction of medium or heat exchange, thereby preventing tank rupture or collapse. There are two types of emissions: atmospheric emissions and pipeline emissions. According to the working conditions, it can be divided into breathing valves, single breathing valves, and single suction valves. The emergency relief valve has two functions: one is to quickly release the overpressure caused by the injection of fire or medium exceeding the design flow rate into the storage tank around the tank; The second is to suck in air for pressure relief when the conventional suction valve is not normally opened and the pressure is constant (for emergency relief valves with suction valves).

  A gas regulating valve is a precise regulating device that maintains a low gas pressure in a storage tank by controlling the flow rate of high-pressure gas, and maintains a positive pressure inside the tank when the medium in the tank is extracted or the gas inside the tank releases heat and the pressure decreases.

   The function of a flame arrester is to prevent the spread of flames within a gas pipeline system to protect low-pressure storage tanks containing flammable media. It can protect the low flash point medium inside the tank by preventing the spread of external heat and flames, thereby improving the fire resistance and safety performance of the tank. Normally, a breathing valve with an outlet to the atmosphere is installed on top of the flame arrester.

3. Working principle

The breathing valve should be installed vertically on the top of the storage tank, with the sealing of the breathing valve in the closed position. When the external temperature rises or materials are injected, the gas medium in the storage tank expands, and its pressure gradually increases. If its pressure exceeds the specified positive pressure breathing value, the exhalation sealing sub valve disc of this valve opens, and the positive pressure is released. When the pressure inside the storage tank drops to the specified value, the valve disc should be closed in a timely manner.

When the external temperature drops or materials are extracted, the pressure inside the storage tank decreases and a vacuum negative pressure occurs. When the specified negative pressure value is reached, the valve suction sealing sub valve disc opens to suck in air or nitrogen. When the pressure inside the storage tank is balanced with the atmospheric pressure of the external air to the specified value, the suction valve disc closes to ensure the normal use of the storage tank.

4. Execution standards

SY/T 0511.1-2010 Oil Storage Tank Breather Valve

API 2000

5. Performance specifications:

1. Opening pressure:

2. Conventional valves are suitable for temperatures ranging from -29 ℃ to+120 ℃. If this range is exceeded, please specify when placing an order.

3. According to different valve materials, it can be applied to petrochemical materials such as gasoline, kerosene, diesel, aromatics, sulfur, air, etc

6. Installation

1. The breathing valve should be installed vertically on the top of the storage tank and should not be tilted or inverted.

2. The pipeline connected to the storage tank shall not be smaller than the inlet diameter of the breathing valve.

3. The inlet and outlet pipes connected to the valve should be supported and cannot be attached to the valve.

4. The breathing valve should be calibrated and inspected once a year, mainly to check its sealing and opening pressure.

5. Aluminum valve inlet gaskets should use full flat gaskets.

6. Before installation, the suitability of the flange gasket and the cleanliness of the flange surface should be checked.

7. Maintenance and upkeep

The breathing valve is stored in a warehouse with rainproof facilities and must not be inverted during storage and transportation. The maintenance and upkeep of the breathing valve should be done once a month, and twice a month in winter. The content and methods are as follows:

1. Check the sealing surface: First, gently open the valve cover, remove the vacuum valve disc and pressure valve disc, and check for oil and dirt at the sealing point between the valve disc and valve seat. If oil and dirt are found, they should be cleaned up and then installed back in place. In maintenance and upkeep, if any abnormal phenomena such as scratches or wear are found on the diaphragm, it should be replaced immediately or contacted by our company for timely resolution.

2. Check the flexibility of opening: Check whether the valve disc guide rod and guide sleeve are blocked, whether there is oil and dirt, pull the valve disc guide rod up and down a few times, check whether the opening is flexible and reliable, and maintain it in a timely manner.

3. Check O-ring: Check whether the O-ring is damaged or aged. If it cannot seal, users can purchase such standard parts themselves or contact our technical department.

4. Check the cleanliness of the inner cavity: Check whether there is rust or foreign matter in the valve inner cavity. If it is dirty, clean it with a clean cloth.

5. For jacketed valves, additional inspections should be conducted to check for fluid accumulation inside the valve and the sealing of the jacket.