The correct operating steps of pump

First, preparation before starting:
1. Test if the motor rotation is correct (the direction indicated on the pump), the test time should be short in order to avoid rotation of the pump internal wear parts because there is no liquid lubrication and dry grinding damage;
2. Open the exhaust valve so that the liquid can fill the pump, to be filled exhaust valves closed;
3. Check that all parts are normal;
4. The high temperature should be preheated heating rate 50 ℃ / h, in order to ensure that all components heat evenly.

Second, startup:
1. Close the pump outlet valve;
2. The pump inlet valve fully open;
3. starter motor, observe the pump is operating properly;
4. Adjust the outlet valve opening to the required conditions, such as user or fitted flow meter gauges at the pump outlet should be made by adjusting the pump outlet valve opening operation at the rated point performance parameters listed in the table, such as user at the pump outlet when not equipped with a flow meter or gauge, should start by adjusting the outlet valve of; measuring pump motor current, the motor runs at the rated current, otherwise it will cause pump overload operation (ie, high-current operation, to make motor burned out) the adjusted outlet valve open and the small and large pipeline-related conditions;
5. Check the seal leaks, the normal mechanical seal leakage should be less than 3 drops / min;
6. Check the motor, the bearing temperature rise ≤80 ℃.

Third, closing down:
1. Close the valve outlet line;
2. Cut off power supply;
3. Close the inlet pipe valve;
4. The long-term parking, the pump should be drained of liquid.

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Repair requirements of centrifugal pump impeller

Impeller replacement
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.SSCN0388

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.

 

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