Pump as a rotating machinery, the shaft and the pump casing must leave a gap between, in order to prevent the liquid from the pump or air leakage into the pump (the entrance for the vacuum situation), the shaft and the pump casing is generally provided with a shaft seal . In recent years due to the continuous development of high temperature and high pressure pump, the sealing problem has become one of the important factors affecting the safety of pump. Currently used shaft seal devices generally have the following forms: packing seal, mechanical seal, labyrinth seal, floating ring seal, and for many low-pressure thermal power plant water pump, the use of soft packing seal. Use asbestos, carbon fiber, PTFE resin and other materials woven into a square or round. Soft packing seal with wide use, cheap and so on. With soft-filled pump usually leaks, the general use of tight disk gland method. If invalid, it is necessary to stop the pump to replace the filler. The soft filler generally short life cycle, and the larger wear on the sleeve, which makes peacetime maintenance increases, and not economical. At this stage can use other methods to replace the use of packing it? Draw lessons from foreign experience and combined with the actuality of China's thermal power plant, packing filler injection method can be used instead of packing. Filler gun The principle of injecting a soft packing is to inject the soft clay filler into the packing chamber of the pump with a higher pressure to replace the rope packing. The other parts of the stuffing box remain unchanged. 1 transformation steps As the low-pressure thermal power plant at this stage multi-purpose packing seal, which is facing a how to transform the original basis, based on experience, are summarized as follows. 1.1 clean up the packing room before the reform thoroughly clean the original packing room of the pump, do not allow any impurities and dirt. If the water ring, can not be abandoned. This work must be uncovered, in order to save time and materials, it is best to carry out the pump overhaul. This will allow overhauls and remodeling synchronization. 1.2 pump cover drilling In order to inject filler, the cap must be installed on the injection hole connector. The connector must be specially machined. The thread should be matched with the stuffing gun connector, and the connector gland should be machined. For the water pump with water seal, the water sealing tube can be removed and drilled and tapped directly on the water seal. 1.3 plus packing root In order to prevent packing leakage and internal leakage, before and after the packing room to be installed at both ends of each packing, you can add carbon fiber packing or PTFE packing. Because it is uncovered after the addition of packing roots, so add packing must pay attention to the gap with the root should be close. 1.4 plus filler first stuffing packing into the packing room, not too tight. Then close the pump cover, bring together the packing gland, and then fill the filler gun can be injected into the pressure. At this point the packing should be tight. 2 Matters needing attention According to Neijiang white horse power plant on the pump of such transformation and maintenance experience, should pay attention to the following items. 2.1 Renovation can only be carried out on the positive pressure pump as in the negative pressure pump (such as water jet pump) on the transformation, the stuffing easily sucked into the pump, at this stage the White Horse Power Plant has been transformed steam turbine workshop industrial pumps, water pumps, circulating pumps, sparse Some low-pressure pumps in the pump and boiler plant work well. 2.2 packing gland not too tight After packing packing tight packing gland not too tight, there should be some loose.