Horizontal multistage centrifugal pump start and stop operation

2019/5/28

Horizontal multistage centrifugal pump start and stop operation
Preparation of horizontal multistage centrifugal pump before operation
1. Check the maintenance records, confirm the correctness of the data, and prepare various records forms for pump application;
2, cleaning machine pump around the health;
3. Check whether the anchor bolts are loose, whether the grounding wire of the motor is in good condition, and whether the inlet pipelines and affiliated pipelines, components and instruments are in good condition;
4. Check whether the coupling is well connected and whether the wheel cover is superior; Before connecting the coupling, check the steering direction of the prime motor and the steering arrow of the pump.
5. Check whether the amount of lubricating oil in the bracket is right (the oil level is about 2mm in the center line of the oil level gauge) and whether the oil level gauge is intact. Add qualified lubricating oil to the bearing part, the oil level is at 1/2-2/3 oil level;
6. Check whether the cooling system is smooth;
7. Check whether the oil sealing system is in normal operation, and the oil sealing pressure should be higher than the pump inlet pressure of 0.05-0.15mpa;
8. There should be no stuck or abnormal sound when turning the car;
9, for the high temperature pump to be fully preheated, the low temperature pump to be precooled;
10. Pump should be pumped or vacuumized before starting when it is used on suction; The pump is used under reverse irrigation. Before starting, the pump shall be filled with liquid delivered. After the empty place in the pump is removed, the gate valve of the discharge pipe shall be closed.
11. Contact the electrician to check the motor and send electricity;

Horizontal multistage centrifugal pump starts
Because horizontal multi-stage centrifugal pump starts, the pump export haven't water in the pipeline, so did not exist high resistance, pipeline resistance and ascension in the sincere pump starts, the pump head is low, traffic is very big, the pump motor, shaft power output is very big, according to the pump performance curve), it is easy to overload, makes the pump, motor and circuit to damage, therefore starts to close the outlet valve, to make the normal operation of pump.
1. Close the inlet and outlet pressure (or vacuum) gauge and outlet valve (if there is bypass pipe, it should also be closed).
2. During the starting process, always pay attention to the power reading of the prime motor and the vibration of the pump. The vibration number should not exceed 0.06mm.
3, check whether the shaft seal leakage meets the requirements, sealing media leakage shall not exceed the following requirements: for mechanical seals, light oil 10 drops /min, heavy oil 5 drops /min; For packing seals, light oil 20 drops /min, heavy oil 10 drops /min.
4. Start the motor when there is no problem; Start the motor (it is best to instill and confirm the correct direction of the pump before starting the formal operation), then open the inlet and outlet pressure (or vacuum) meter, when the pump reaches the normal speed and the corresponding pressure is indicated by the meter, slowly open the outlet valve and adjust to the required condition.
5, when the horizontal multi-stage centrifugal pump outlet pressure and motor current are normal, gradually open the pump outlet valve, and closely monitor the motor current, the current control in the red line, in order to prevent overload of the motor, burn out the motor;
6. Check whether the outlet pressure indicator is normal and the lubrication condition is good;
7. Sealing conditions: the mechanical seal shall be free from leakage and heat, and the packing seal shall be in a continuous drip state.
8. Check whether the cooling system operates normally;
9. Check whether the vibration value and bearing temperature of horizontal multi-stage centrifugal pump are within the allowable range. Vibration values shall meet ISO 2372 and ISO 3495 standards. Bearing temperature shall meet the following requirements: for forced lubrication system, the temperature of bearing oil shall not exceed 28℃, and the temperature of bearing metal shall be less than 93℃; For ring lubricants or splash lubrication systems, the temperature rise of the oil pool shall not exceed 39℃.
10, pay attention to the pump outlet flow and pressure at any time, and judge the blocking of the filter according to its changes, when the blocking is serious, should immediately stop the pump treatment.
11. Seriously and properly deal with the problems in operation, and make detailed records, and cooperate with other positions to handle the follow-up work.
run
12. Frequently check the heating condition of pump and motor (temperature rise of bearing should not exceed 75℃) and oil supply condition of oil level gauge. (generally, the lubricating oil should be changed once every 1500 hours).
13. The suction valve cannot be used to regulate the flow to avoid cavitation.
14, stainless steel horizontal multistage centrifugal pump should not be under the design flow of less than 30% continuous operation, if it must be under the condition of continuous operation, should be installed in the outlet bypass pipe, discharge excess flow.
15. Pay attention to whether there is any noise in the operation of horizontal multistage centrifugal pump. If abnormal state is found, it shall be eliminated or stopped for inspection in time.
parking
First, slowly close the gate valve of the discharge line (if the pump is used in reverse irrigation, also close the gate valve of the suction line), and turn off the switches of various meters.
Cut off the power supply and turn off the motor.
Three, if the seal USES the external liquid diversion, but also close the liquid diversion valve.
Four, if the ambient temperature is lower than the liquid freezing point, to put the net liquid in the pump, in order to prevent freezing crack.
Five, if not used for a long time, in addition to the corrosive liquid in the pump, all parts should be removed and cleaned, especially the sealed chamber. It is best to remove the pump after cleaning re - installed, in addition to oil anti - rust treatment and seal the pump into, export, but also should be regularly checked.