The introduction of the tank breathing valve, what is the function of the tank breathing valve

The breathing valve of the storage tank mainly meets the ventilation requirements of the size of the storage tank, and is installed on the top of the storage tank for storing Class A, B and C liquids with the flame arrester. The tank breathing valve is an important accessory to protect the safety of the oil tank, which is installed on the top plate of the oil tank and consists of two parts: pressure valve and vacuum valve. Its function is to maintain the airtightness of the oil tank and reduce the evaporation loss of oil to a certain extent.

When necessary, it can automatically ventilate to adjust and balance the internal and external pressure of the oil tank, which plays a safe role in the oil tank.

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following are the top ten domestic first-line valve brand manufacturers in 2022-2023, but for reference only: Suzhou Neway Valve Co., Ltd., Shanghai Guanlong Valve Machinery, Shanghai Qizhong Valve Manufacturing, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

Abstract:The tank breathing valve is a safety component that meets the ventilation requirements of the size of the tank, and its function is mainly two, one is to keep the tank closed under normal conditions, and the other is to automatically ventilate when necessary to adjust the pressure inside and outside the tank. There are generally four types of breathing valves for storage tanks: tight, packing, self-sealing and oil-sealed, no matter which one they are, their basic working principles are similar:

Usually the breathing valve does not work and remains sealed; When the medium is replenished to the tank, the pressure valve is opened to maintain the pressure balance inside and outside the tank. Let's take a look at what the function of the tank breathing valve is. 1. What is the function of the tank breathing valve?

The tank breathing valve is a component installed on the top of the tank, which is mainly used to meet the ventilation requirements of the tank size breathing, and is an important accessory to protect the safety of the tank.

The storage tank is generally composed of two parts: a pressure valve and a vacuum valve, and its function is to maintain the tightness of the storage tank under normal circumstances, and reduce the evaporation loss of the stored substances in the storage tank to a certain extent; When necessary, it can automatically ventilate and adjust the pressure inside and outside the storage tank, which plays a safety role in the storage tank.

2. There are several kinds of tank breathing valves.

There are many types of tank breathing valves, and there are roughly the following four types:

1. Lock-type breathing valve.

Lock-in breathing valves are usually used for low-pressure through-pipes, and the sealing performance depends entirely on the fit between the plug and the plug body, and the compression of the sealing surface depends on tightening the nut at the bottom. Generally used for PN.

2. Packed breathing valve.

Stuffed breathing valves seal the plug and plug body by pressing down on the packing. Due to the packing, the sealing performance is better. Usually this type of breathing valve has a packed gland, and the plug does not have to protrude from the valve body, thus reducing a leakage path for the working medium.

This breathing valve is used in large quantities for pressures of PN 1MPa.

3. Self-sealing breathing valve.

The self-sealing breathing valve is a compression seal between the plug and the plug body by the pressure of the medium itself. The small head of the plug extends upwards out of the body, and the medium enters the big head of the plug through the small hole at the inlet, and the plug is pressed upward, which is generally used for air medium.

4. Oil-sealed breathing valve.

Nowadays, the range of applications for breathing valves is expanding, and oil-sealed breathing valves with forced lubrication have appeared. Due to forced lubrication, an oil film is formed between the sealing surface of the plug and the plug body. In this way, the sealing performance is better, the opening and closing are labor-saving, and the sealing line is prevented from being damaged.

What is the working principle of the three-gear finger and tank breathing valve?

The principle of operation of the tank breathing valve is simple:

When the pressure of the medium in the tank is within the control operating pressure range of the breathing valve, the breathing valve does not work, and the tightness of the storage tank is maintained; When the medium is added to the tank, the pressure of the upper gas space in the tank is increased, and when the positive pressure of the breathing valve is reached, the pressure valve is opened, and the gas escapes from the breathing valve, so that the pressure in the tank does not continue to increase; The atmosphere outside the tank will open the negative pressure valve disc of the breathing valve, isolating the space in the tank from the atmosphere, so as to protect the safety of the tank.

Principle of determining the size of the external vent of the oil tank breathing valve (selection table).

When the size of the external vent of the breathing valve is selected in the oil tank, the caliber and number of the breathing valve need to be determined to ensure that the breathing volume of the breathing valve is sufficient to balance the pressure of the storage tank.

The size of the caliber of the suction valve and the number of selections are mainly related to the maximum amount of liquid in and out of the storage tank, and the volume of the tank itself is not directly related, of course, the larger the diameter of the breathing valve required by the general volume of the storage tank, the more the number will be (limited by the caliber range, sometimes a plurality of breathing valves need to be selected), combined with the industry design standards, our factory will be the breathing valve caliber and the maximum amount of liquid in and out of the storage tank The relationship is sorted out in the following table:

Maximum liquid volume in and out of the storage tank (m hours) Select the diameter of the breathing valve (mm) * number.

25 DN80*1pcs.

26-50 DN100*1pcs.

51-100 DN150*1pcs.

101-150 DN150*2pcs.

151-250 DN200*2pcs.

251-300 DN200*2pcs.

301-500 DN250*2pcs.

501-700 DN300*2pcs.

701-1000 DN300*3pcs.

1001-1500 DN350*3pcs.

Note: When the flash point of the medium in the tank is 60, a breathing valve with flame retardant function should be selected; When the average temperature of the coldest month in the coldest month in the tank construction area is below zero, anti-freezing measures need to be taken for the selected breathing valve;

According to the maximum amount of liquid in and out of the tank per hour to choose the breathing valve is the most scientific and universal practice, if the amount of liquid in and out of Zi Oak Mountain is very small, you can also choose the breathing valve below DN80, as long as the breathing volume of the breathing valve meets the actual demand.

The tank breathing valve is a ventilation device installed on the top of a fixed storage tank or oil tank, which plays the role of reducing oil evaporation loss, controlling the pressure of the storage tank, keeping the pressure balanced, and preventing the introduction of external flames. The valve has the characteristics of large ventilation, small leakage, corrosion resistance, etc., and has an electrostatic grounding wire.

The mechanical breathing valve relies on the weight of the valve disc itself to control the expiratory pressure or suction vacuum of the oil tank to maintain a certain pressure in the tank. The rated control pressure of the pressure valve is generally 2kpa, and the rated control pressure of the vacuum valve is generally 2kpa. When the oil and gas pressure in the tank is greater than the allowable pressure of the oil tank, the oil vapor escapes through the pressure valve, and the vacuum valve is in a closed state; When the oil and gas pressure in the tank is less than the allowable vacuum degree of the oil tank, fresh air enters the tank through the vacuum valve, and the pressure valve is closed at this time, and the allowable pressure (or vacuum pressure) is controlled by the weight of the adjusting plate.

It must be noted in use that if the breathing valve seat disc is too light or damaged, it is easy to cause a large amount of vapor of light oil in the tank to escape to the outside of the tank, or the valve disc is out of order, which may cause the risk of bursting or deflating. Mechanical breathing valves can sometimes rust and clog, and in the winter the disc and seat can freeze due to water content in the oil vapor.

1. Please indicate whether the ordered product is all-weather type (Q) or ordinary type (P) according to the statement in the product manual, and indicate the pressure level and specifications of the required product.

2. The key parts of the valve of the product are made of PTFE material. In use, it is impossible to open the positive and negative pressure valves at the same time. Therefore, the product should be inverted and subjected to violent collision during storage, transportation and installation.

3. The sliding performance of the positive and negative valves and the fire retardant core of the product should be cleaned and inspected once every six months. to ensure normal opening and flame retardant performance.

4. Please pay attention to the name, model, specification and specific specifications when ordering.

When the pressure drops to the allowable vacuum value of the breathing valve, the air enters the tank, so that the oil and gas concentration of the gas space is reduced, and the oil and gas evaporation creates conditions for the evaporation of oil and gas after the temperature rises. This repeated cycle results in a small loss of breathing in the tank. When the oil is discharged from the tank, the volume of the liquid in the tank decreases, the pressure of the gas in the tank decreases, and when the pressure drops to the negative pressure limit of the breathing valve, the air is sucked in.

This kind of loss caused by the removal of oil vapor and the inhalation of air from the oil tank due to the transfer of oil is called "big breathing" loss.