(1) centrifugal pump mouth ring (also known as the seal ring) WRY thermal oil pump mouth ring is the role of the impeller and the pump shell between the formation of narrow, tortuous channel, increase the flow resistance of media, the purpose of reducing the leakage of medium. Centrifugal pump port ring is also set up to protect the main parts of the pump wear and tear, wear rings in the mouth, can be repaired or replacement rings, to restore the normal assembly gap, so that the economy and easy to maintain. Centrifugal pump mouth ring structure usually has radial clearance ring type, double step type, double ring labyrinth type and axial gap type. Centrifugal pump mouth ring integrity, it is with the impeller radial clearance of the requirements, the first should check the pump. If the centrifugal pump mouth ring has a groove defect or has broken or gap, more than the specified value, should be replaced by the new mouth ring or the original export ring welding repair. Wu Yan heat-conducting oil pump, centrifugal pump mouth ring and the impeller corresponding circle is at the same time wear, caused the increase of the gap exceeds the specified value, because the new export ring diameter should be according to the preparation of the diameter of the inlet, impeller and centrifugal pump mouth ring radial clearance between the reference set. In the repair process, the gap is small, in order to improve the efficiency of the pump and extend the life of the pump. Mouth ring material generally available gray cast iron HT200, tin bronze or tin bronze bearing alloy (alloy). For the hanging bearing alloy of copper ring, when the gap mill, just re hung alloy, yuan to replace the new mouth ring. When the original alloy wear is small and no peeling off phenomenon, the repair welding method can be used to repair. Repair welding procedure is as follows. 1, remove the dirt on the 2 ring, with 5% hydrochloric acid cleaning and activating it again. In 3, temperature is 90, the mass fraction of l0% in 10min liquid caustic soda immersion, and then placed in 90 DEG C water cleaning. 4, repair welding alloy. Saliva preheating ring to l00 DEG C, with appropriate welding molten opening ring on the original alloy, with cast as a electrode alloy with same brand pre alloyed, centrifugal pump edge ring circumferential or longitudinal direction even a road surfacing up (not re welding. After welding, mechanical processing can be carried out to achieve the required standard size. If the alloy is too large to be stripped off or worn out, it will not be repaired with repair welding. After the new port ring installed, should check whether it is in line with the centrifugal pump impeller clearance requirements. At the same time, to check between with and without friction phenomenon, the method is on the part of the rotor coated with red lead powder, and then rotate the rotor. If a mouth ring is stained with red lead powder must be repaired.