The acetylene content in liquid air and liquid oxygen needs to be analysed every day, so the liquid air and liquid oxygen discharge valves have to be operated every day.
The problem arises when it is easy to open the valve, but difficult to close it, sometimes even a little can not be closed. This is mainly due to the presence of moisture at the valve stuffing box. When the liquid is discharged, the temperature drops and freezing occurs. In order to prevent this, the valve should be turned continuously at the beginning of the discharge of the liquid so that the stem does not freeze. If freezing has occurred, steam can be used to heat the stuffing box before it is closed.
Dear Air Separation has a lot of practical experience in all aspects of technology, piping and valves in the long-term small air separation units manufacturing and design process, requiring high quality large air separation units and liquid air separation plants and providing a full range of technical services to customers.