(a), Shaft seal inspection：

For packing sealed pumps, it is necessary to check the sealed water used, whether the amount of sealed water is sufficient, and whether the pressure is normal.

For the slurry pump, the sealing water pressure should be 0.05MPa higher than the outlet pressure of the pump, and the packing gland should be adjusted to obtain a small stream of water along the shaft. Note that the pump supplied directly by the slurry manufacturer has a tighter packing gland, in order to reduce the vibration of the shaft during transportation.

Centrifugal seal, pay the impeller to seal the pump, and unscrew the grease sealing cover a few times to refuel the sealing chamber.

Rubber-lined pumps have rubber pressure reducing caps. This kind of pump is usually sealed with a lip-type rubber ring, and no butter is required.

(b), Loose shaft：

In order to prevent shaft vibration and damage during transportation, the slurry pump bearing must be locked tightly. A wrench (one of the assembly tools) is often used to tightly screw the positioning screw to the bracket to tighten the bearing.

Before the pump is running, the positioning screws must be removed to restore the bearing to freedom. Then, use a wrench to rotate the shaft clockwise to see if the shaft drives the impeller to rotate freely. If there is any noise, it should be eliminated by adjusting the impeller gap (see Pump assembly: Impeller gap adjustment).

(c) Check the direction of rotation of the motor：

Remove all V-belts or the entire coupling. In particular, it should be noted that if the direction of rotation is opposite to the direction of the arrow marked on the pump, then the impeller will buckle loose and fall off the shaft, which will damage the pump.

Start the motor and check the direction of rotation. If it is wrong, correct it. Make sure that the pump shaft rotates in the direction of the arrow marked on the pump body.

Reinstall the V-belt or coupling, and ensure that the rear axle is aligned after the belt is tightened.

(d), the start of the pump：

Check whether all the belts are tightened, whether the impeller is free to move, and whether the shaft seal is normal. If the shaft seal is used, check whether the pressure is correct.

Experiments have shown that whenever possible, the pump should be started with water before pumping the slurry, and when the pump is stopped, the pump should be pumped for a while before the pump is stopped.

Open the valve of the suction line (if there is such a valve), check the inlet of the pump for blockage, start the pump and motor and make it reach normal speed, if the pump is working under suction conditions, then apply the provided device according to the water diversion procedure.

After the pump draws water, isolate the water diversion device (if there is such a device) and check the suction and discharge outlet pressure (if pressure gauges are installed in both places).

The flow rate is measured by the flow meter, or the flow rate is estimated by observing the outlet.

Check the amount of leakage at the packing place. If the leakage is not large, and the packing gland is a bit hot, then loosen the gland nut. If it does not work, that is, the gland continues to heat up. The pump should be stopped to cool the gland, and the gland nut should be loose to the extent that the filler behind the gland is active.

note：

Even if the leaking water of the filler is hotter than the water supplied to the filler, this is normally allowed, because the leaking water of the filler will take away the heat generated by the friction in the filler.

When operating at low pressure (single-stage), very little leakage is required, because the low-pressure pump allows operation with a small amount of water leaking from the filler, and the pump does not have to be stopped immediately when the filler heats up, unless there is hot steam or smoke. Stop the pump.

*The comments on the reference page are about the assembly of the pump.

The heating of the packing is usually only encountered when the pump is started. That is, when the pump is turned on for the first time and the packing is heated, the general method is to start—stop—cool, and start 2-3 times until the packing and the bushing run well.

A better way to solve the heating of the filler is to let the leakage exceed the rated value when starting the pump. After the pump is running for 8 to 10 hours, the gland bolt is used to adjust the leakage of the filler to the ideal value..

If the filler always heats up, the filler should be replaced.

When the outlet pressure is below 0.5Mpa, use butter-boiled cotton thread packing or oil-immersed asbestos packing. When it is greater than 0.5MPa, use polytetrafluoroethylene packing or carbon fiber-immersed tetrafluoroethylene packing packing, more than 1MPa, usually install a packing ring between the gland and the nearest circle of packing.

(e) Abnormal start-up

If the pump cannot divert water, it may be caused by one or more of the following reasons.

(1) Filling of suction tube

After the pump is running for a period of time, it is likely that the slurry will settle in or around the suction pipe due to water absorption from the pit pool, thus preventing water from entering the impeller. The pressure gauge at the suction port of the pump can be used to check the water level in the pump.

(2) Air enters the pump from the filler

Any of the following working conditions can cause air to enter the pump through the filler, and air entering the pump often prevents the pump from diverting water or interrupts the water diversion during operation.

1), the sealing water pressure is too low；

2), Excessive wear of the filler；

3), The packing sealed water is clogged through the pipeline of the packing box.

If the above-mentioned failure occurs, it can be checked out through the packing in advance, then there is a remedy.

(f), Operation failure

Ⅰ), The suction tube is clogged

It is very likely that during the operation of the pump, impurities are pumped to the bottom of the suction pipe, causing local blockage. This blockage does not cause the pump to stop, but it can reduce the flow rate of the pump.It can also continue to reduce the outlet pressure and increase the degree of suction vacuum. It may also cause the pump to be in abnormal operation and vibration due to cavitation in the pump due to the high suction vacuum.

Ⅱ), The impeller is clogged

The impeller allows a certain particle size of material to pass through. If the particle size of the material enters the suction line, the inlet of the impeller may be clogged, thereby limiting the discharge of the pump. This kind of failure often leads to a decrease in power and a decrease in outlet pressure and suction vacuum.

The vibration of the pump may also be caused by the unbalanced action of the impeller.

Ⅲ), The outlet pipeline is blocked

Blockage of the discharge tube occurs when thick particles are highly concentrated in the discharge tube of the pump, or because the speed of the discharge tube is too low to adequately transport the liquid. Blockage like this will be reflected in the increase in outlet pressure and the decrease in motor power.