1. Before the shaft seal is supplied with steam, it is required to firstly warm up the pipe and to drain the water.
2. It is necessary to supply steam to the shaft seal after the turning gear has been continuously operated. Before hot state start, the shaft seal shall be supplied with steam firstly and then it is vacuumed.
3. The time for supplying steam to the shaft seal shall be proper, if the shaft seal is supplied with steam too earlier before impulse starting, the temperature difference or expansion difference between upper and lower cylinders will be greater.
4. It shall be noticed that the temperature for supplying steam to the shaft seal is matching with the metal temperature. Proper steam source is used for hot start, which is beneficial to the control of expansion difference. If the temperature of the steam supply to the shaft seal can be adjusted by the system, and it is better that it is higher than the shaft seal body, but cold start will use low-temperature steam source.
5. It shall be cautious to switch over high-temperature and low-temperature steam source, too quickly switching over not only will cause the significant change of expansion difference, but also will produce uneven thermal deformation at the shaft seal position, thus causing friction and vibration.