New steel drum breathing valve

New steel drum breathing valve

â–¡ Yang Wenliang

Steel drums are mainly used for the storage and transportation of petrochemical products and other closed containers, which are processed from steel plates. Usually, there are two holes in the top of the closed steel drum, a large hole with a diameter of 60 mm, called the injection port; and another small hole with a diameter of 27 mm, called the vent hole. The purpose of the injection port is generally known as the passage for injecting liquid or pouring out liquid. But venting holes, but many people do not know its function, some people never use it, this is not right, in fact, it is very important, some people have caused the accident and still do not know the reason.

When the steel drum is filled with oil, it is generally not filled, and it can only be loaded to 80%~90% of its capacity, that is, there should be a certain space. The gas space inside the barrel changes continuously during loading and unloading. When pouring out, the oil level in the barrel gradually decreases, and the gas space gradually increases, causing a negative pressure to form in the barrel, which may deform the steel drum, and the air is returned from the injection port to the barrel, and is poured. The oil produced has the opposite countercurrent and strong friction, which is prone to static electricity causing fire or explosion. When oil is loaded, the oil level will gradually rise, and the gas space will gradually decrease, causing the gas pressure in the barrel to rise, which may cause the steel drum to rupture and leak. Therefore, when loading and pouring oil, it is required that the vent hole must be opened.

However, due to changes in temperature, the gas space in the barrel will also change. When the temperature rises during the day, the oil in the barrel will expand and the gas pressure will increase. When the nighttime temperature drops, the volume of oil in the barrel decreases, thus creating a negative pressure. In this way, as in the case of loading oil and pouring oil as described above, compression deformation or bursting occurs.

In order to maintain the pressure balance inside and outside the barrel to ensure safety, when the pressure inside the barrel rises, the gas should be discharged; and when the negative pressure is formed in the barrel, the air outside the barrel should be sucked into the barrel to replenish the space. . However, to achieve this goal, the vent hole of the steel can be powerless, because it is impossible to open or close the vent hole in time, which is too cumbersome and impossible to do. Therefore, a steel bucket-specific breathing valve was designed to replace the venting hole. As the name suggests, the breathing valve is the breathing organ of the steel barrel.

This type of breathing valve is equipped with two valves: a pressure valve and a vacuum valve. The pressure valve is the outlet of the gas in the steel drum. When the pressure of the gas in the barrel increases, the valve is opened, so that the gas in the barrel flows into the atmosphere. The vacuum valve is the inlet of the air. When a negative pressure is formed in the barrel, the valve is opened to allow outside air to enter the barrel. The breathing valve is a safety device for the steel drum. It can keep the steel barrel sealed to prevent evaporation or leakage of the contents, and it is beneficial to the safety of the steel drum. When the gas space in the barrel changes, the gas is automatically adjusted to enter and exit, and the pressure inside the barrel is adjusted to prevent the steel barrel from bursting or crushing and leaking, thereby ensuring the safety of the steel drum during loading, unloading, storage and transportation.