Impeller may be damaged after using, so when impeller has the following circumstances, it should be replaced.
1) The surface of the impeller with some cracks.
2) The surface of the impeller form more perforations due to corrosion, erosion or cavitation.
3) The impeller blades and the cover become thinning due to erosion, it will affect the mechanical strength.
4)The impeller hub ring opening occurred more serious side wear phenomenon without repair by value.
The repair of the impeller
1) Impeller corrosion is not as severe trachoma much, can repair welding method. Welding copper with brass impeller, cast iron impeller can also be made of brass welding.
2) Welding method is required before welding to welding of parts to clean, remove oil, rust, scale and so on. Or may be locally preheated to 250 ~ 450 overall. C. Solder powder is generally used in powder 30i, 224 silk wire usually used silicon brass wire, welding flame should be neutral or slightly oxidizing flame flame, the general method of bonding operation, to reduce overheating of the weld metal, weld and improve forming, in operation, should avoid direct contact with the flame core temperature of the metal bath to avoid porosity in the weld metal. After welding, insulation slow cooling to eliminate stress, improve performance. After cooling, it can be machined.
3)Single-loop port hub ring grooves to wear out, or side wear is not serious, the available emery cloth polished in thickness also permits the car light. Or metal spraying, restore the original size.
4)Bicyclic ring sealing edges worn inside the mouth of the grooves, or side wear phenomenon is not serious, can also be polished with emery cloth, in the thickness of the light car is also permitted. Wear or eccentric wear serious, can be replaced with new inner ring.
5)New or reconditioned impeller should be static balance test. Impeller balanced approach is spent weight method can be tried out onto the impeller milling, face milling in which the heavier and lighter to that side of the object at the time of trial balance and other heavy sandwiched chips. But in the impeller cover milled to a thickness of no more than 1/3 the thickness of the impeller cover, allowing the cut in two on the front and rear cover, a smooth transition should mark the cutting portion and the cover disc.