Breathing valve series

main purpose

According to the national standard "Fire Protection Design Code for Petrochemical Enterprises" (GB50160-90), fixed top tanks for Class A and Class B liquids; Apply flame arresters and breathing valves. It can be seen that breathing valves and flame arresters are indispensable safety facilities for storage tanks. They can not only maintain the pressure balance of the storage tank, ensure that the tank is not damaged under overpressure or vacuum, but also reduce the volatilization and loss of the medium inside the tank. Breathing valves are safe and energy-saving products that maintain the pressure balance of the storage tank and reduce the volatilization of the medium. They are often used in conjunction with flame arresters.

working principle

When the container is under positive pressure, the breathing valve opens to exhale gas and release positive pressure; When the container is subjected to negative pressure, the fire breathing valve opens to suck in gas and release the negative pressure. This ensures that the pressure is within a certain range, ensuring the safety of the container. Fire breathing valves can not only maintain the pressure balance of the storage tank to ensure that it is damaged in case of overpressure or vacuum, but also reduce the medium and loss inside the tank. Explosion proof flame retardant breathing valve, one type is to exhale or inhale when a certain pressure is reached. Another approach is to design it purely as breathing without inhaling. It can be understood as replacing it with two one-way valves of appropriate pressure. Explosion proof fire-resistant breathing valves can not only maintain the pressure balance of the storage tank, ensuring that the tank is damaged in case of overpressure or vacuum, but also reduce the medium and loss inside the tank. The explosion-proof flame arrester breathing valve integrates the flame arrester and breathing valve, and its novel structure is the first of its kind in China. It is a new type of safety equipment essential for petrochemical storage tanks, with the greatest advantages of good flame retardant breathing performance, light weight, and easy maintenance.

The flame retardant breathing valve is a ventilation device installed on a fixed top tank to reduce oil evaporation loss and control the pressure of the storage tank. It has high ventilation, low leakage, good corrosion resistance, and anti freezing performance. It can automatically adjust the pressure inside and outside the oil storage tank.

The valve body of the flame retardant breathing valve can withstand a water pressure of 0.2 MPa without any leakage or deformation. The low-temperature resistance performance of the breathing valve is high when the relative humidity of the air is greater than 70% and the minimum temperature is -30 ℃. After 24 hours of freezing, the opening pressure of the valve disc meets the working pressure requirements (allowing a pressure difference of plus or minus 20pa). When the valve disc component of the G-to-Q type ventilation pipe is operated, it has high sensitivity and ensures sealing after the operation is completed. There is sufficient space inside the breathing valve to ensure the ventilation of the storage tank. Before the breathing valve reaches its working pressure: the nominal diameter is 150mm, and its leakage rate is ≤ 0.04m3/h; The nominal diameter is ≥ 220mm, and the leakage rate is ≤ 0.4m3/h; When the breathing valve reaches the working pressure, the valve disc immediately opens to ensure the normal ventilation requirements of the storage tank.

Main technical parameters

Operating pressure:

A型: +355Pa(+36mmH20)、-295Pa(-30mmH20)

B型: +980Pa(+100mmH20)、-295 Pa(-30mmH20)

Type C:+1750Pa (+180mm H20), -295Pa (-30mm H20)

D-type: Special pressure, specified by the user.

Fire barrier material: 304 stainless steel.

Explosion proof grade: BS 5501; IIA, IIB, IICo

Flange standards: GB, HG, SH, HGJ, JB, ANSL,

JIS and other standards. Manufacturing and testing standards (specified by the user, please indicate pressure rating): Manufacturing and acceptance shall be carried out in accordance with (oil storage tank breathing valve) SY7511-87, (oil storage tank flame arrester flame retardant performance and test methods) GB5908-86 and other standards, or user specified standards.

Main Features

The fire-resistant breathing valve plays a safety protection role in the system. The flame retardant breathing valve plays a role in blocking steam and draining water in the steam heating system. Choosing a suitable breathing valve can achieve the highest working efficiency of the steam heating equipment. The working principle of the flame retardant breathing valve is to use a spring limit valve plate, which is determined by positive and negative pressure to either exhale or inhale. The breathing valve should have both positive and negative pressure relief functions.

The breathing valves produced by our company have the characteristics of compact structure, high ventilation capacity, low leakage, corrosion resistance, and good sealing performance. Recently, we have also developed an internationally advanced explosion-proof flame retardant breathing valve (Japanese XF-IZ type), with the flame arrester located at the suction port of the breathing valve, completely preventing the entry of fire sources into the breathing valve housing; Small size, light weight, and easy maintenance; Advantages such as easy cleaning and replacement. The valve disc is made of polytetrafluoroethylene material, which has the advantages of low temperature resistance, anti freezing, etc. An electrostatic output device is installed inside the valve to maintain an equal potential with the tank at all times.

Maintenance and upkeep methods

1. Storage: After the respiratory valve products arrive at the construction site, if they are not installed temporarily or undergo major repairs or maintenance in the factory in the future, they should be stored in a warehouse with rainproof facilities. The respiratory valve series products should not be inverted during transportation.

2. Maintenance: a. Breathing valve series products should be inspected on the top of the tank once a month to check for dust and dirt on the valve disc, valve seat, valve stem, valve sleeve, and other parts. If there is any, it should be cleaned thoroughly.

3. The flame retardant layer of the breathing valve of the flame arrester should be checked every six months. If stains or impurities are found blocking the flame retardant layer, the flame retardant layer should be removed, and the corresponding solvent should be used to remove the stains. Then, the flame retardant layer should be cleaned with clean water, and placed in the shell after ventilation and drying.

4. The paint on the inner and outer surfaces of the above product shells should be applied once a year.

5. For the safe use of the breathing valve, the corrugated fire-resistant layer should be removed and cleaned regularly within 3-6 months to ensure that each hole on the fire-resistant layer is unobstructed, prevent blockage, and ensure safe and normal use. Regularly check whether the positive and negative valve discs of the ventilation system operate flexibly, and whether the sealing surface of the guide rod and valve disc is damaged. If there is any damage, it should be replaced immediately. When inspecting, maintaining, and reinstalling, it should be ensured that the joint surfaces inside the valve are tightly matched and the valve disc is flexible in lifting and lowering. When a new valve is activated, the shock absorbers between the valve discs should be removed before installation, otherwise the breathing valve will malfunction.

Installation steps

1. The breathing valve should be installed at the highest point of the gas source in the storage tank to reduce material evaporation loss and provide the most direct and largest passage to the breathing valve smoothly. For vertical tanks, the breathing valve should be installed as much as possible within the central top plate range of the tank roof. For tanks that require insulation on the tank roof, it can be installed near the ladder platform;

2. When two breathing valves need to be installed, they should be symmetrically arranged with the center of the tank top;

3. If the breathing valve is used on a nitrogen sealed tank, the connection position of the nitrogen supply pipe should be far away from the breathing valve interface and inserted into the storage tank from the top of the tank by about 200mm, so that nitrogen is not directly discharged after entering the tank, achieving the purpose of nitrogen sealing.

Ordering Instructions

1. Please indicate the product size, operating pressure, and material when placing an order.

2. When other standard flanges, materials, or operating pressures are required, please specify them when placing an order.