The original packing seal of the main steam isolation valve uses ordinary graphite. This type of packing is troublesome to disassemble and assemble, and has poor reusability. In addition, during the operation of the valve, the graphite is easily extruded and leaks may occur.
The heavy water reactor container box uses a rubber gasket with a wide sealing surface, which results in insufficient bolt pre-tightening and low sealing specific pressure, making it difficult to meet the sealing requirements. In addition, outstanding problems such as easy aging of rubber and short service life are also the main reasons for container box sealing failure.
The sealing surface of the original metal seal ring is too wide, and it is difficult to obtain sufficient sealing specific pressure even with a large bolt pretightening force, which can easily cause leakage.
The original packing used was Acrylic round solid silicone strip packing. This type of packing had poor lateral extensibility, failed to provide sufficient sealing specific pressure for the side wall sealing surface, and had high friction resistance.
'XX' The ship's generator exhaust pipe used spiral wound gaskets to leak. After investigation by technicians, it was found that it was difficult to ensure balanced tightening bolt torques in the limited installation space, and some gaskets had even been crushed, causing leaks.
The sealing packing of the water pump circulation pipe is a pure graphite ring. According to the analysis of on-site surveying and mapping data, it is found that the gap in the stuffing box is too large, and the graphite in the stuffing box overflows from the gap or is washed away. After repeated pre-tightening, the volume of the graphite gradually decreases, resulting in sealing failure.
The sealing packing of the water pump circulation pipe is a pure graphite ring. According to the analysis of on-site surveying and mapping data, it is found that the gap in the stuffing box is too large, and the graphite in the stuffing box overflows from the gap or is washed away. After repeated pre-tightening, the volume of the graphite gradually decreases, resulting in sealing failure.
Ningbo Tiansheng Seals Co., Ltd. was established in 1998. It is mainly engaged in the research and development, technical support and program design of sealing systems in high-end fields, nuclear power, shipbuilding, aerospace, petrochemical and other related fields.
