one,Piston breathing valve
The piston breathing valve is mainly composed of a piston, a diaphragm, a weight and a manual operating handle. When the pressure in the cabin rises to 0.14×10Pa, the diaphragm and piston installed on the upper part will be pushed up under the action of this pressure. Automatically open the valve in the middle to release the gas in the cabin; and when the pressure in the cabin drops to -0.07×10Pa, the valve will be directly pushed upward under the action of atmospheric pressure, thereby sucking in external air to fill the oil tank. When this type of breathing valve is used for loading and unloading cargo oil, ballast, etc., the operating handle can be manually opened (forcibly lift the valve), so as to allow a large amount of gas to be sucked and discharged quickly.
Piston type breathing valve will often cause the valve to be stuck and unable to move due to the accumulation of oil dirt, rust and other sundries on the moving parts of the valve, valve seat and piston. Therefore, it is necessary to operate the handle for manual operation frequently to check whether it is stuck, and to dismantle and clean it regularly to ensure its normal working condition.
2. Gravity breathing valve
There are two weights in the gravity breathing valve body. When the breathing valve is placed in the “normal” position, the valve is in the working state of automatic breathing. When the pressure in the cabin rises above 0.14×10Pa, the lower weight will move upwards with the help of the gas pressure (the upper weight will be pressed and kept still), so that the gas in the cabin can be released into the atmosphere; When the internal pressure drops below -0.07×10Pa, the upper weight moves upwards with the help of atmospheric pressure (the lower weight is pressed to keep it still), and the outside air is sucked into the cabin.
The gravity breathing valve has a small capacity and is generally only suitable for independent ventilation system installation. In addition, this kind of valve is prone to sticking so that the action fails, so the action check and cleaning should be carried out frequently during use.
The above is the whole content of the breathing valve structure shared with you today, let’s get it up~