Safety Precautions for Using Slurry Pumps

Posted by angroup on March 9, 2022


Before installing the coupling or belt, check that the steering of the drive is correct and look at the slurry pump for clockwise rotation It is strictly prohibited reverse operation! Otherwise, there will be great damage to people and equipment.

The sludge pump must not be operated for a long time at low or no flow. Otherwise, it will cause the pump unit vibration or even pumping liquid Vaporization, cause equipment damage

The pump is rotating equipment, before installing and maintaining the pump unit, must cut off the power. Otherwise may cause personal injury.

When the pump unit operates, it is forbidden to enter or remove the protective cover, otherwise, it will cause personal injury.

Assembly precautions

Bearing component assembly

Preheat the inner ring of the bearing during assembly, the temperature is not allowed over 1200C, The bearing inner ring must be fastened to the shaft shoulder or butter retaining ring

For A, B, C, D, E, F, G type bearing components, using a single row of tapered roller bearings, Assembly should be adjusted at the end of the bearing pad to ensure that the axial clearance, axial clearance should be consistent with the following table:

Axial clearance0.05-0.150.1-0.20.15-0.250.18-0.280.4-0.60.5-0.6

For R, S, ST, T, TU, U bearing components, double row tapered roller bearings are used in the pump end. As the bearing itself has ensured the axial clearance, it is not necessary to adjust the axial clearance.

When assembling the bearing, pay attention to adding the appropriate amount of bearing grease, Bearing end cover is sealed with a piston ring and a labyrinth. When installing the piston ring, note that the gap is diametrically opposed to the arrangement.

The bearing grease is recommended lithium grease 2 # or 3 #. The amount of grease added during assembly can refer to the following table:

Grease amount
Frame type
Drive end bearing305010020050011502005001150
Pump end bearing3050100200500115040010002300

Install pump frame plate and cover plate: When tightening the frame plate bolts, tighten the Angle evenly to avoid unevenly damaging the fame plate and cover plate.


Slurry pump starting

Before starting, check the entire unit as follows

The slurry pump should be placed on a solid foundation to withstand the full weight of the sludge pump to remove vibration, tighten all the anchor bolts

The inlet and outlet pipes should have their own brackets. The pipe weight can not be imposed on the pump and the pump and pipe can not be installed when they are not on the same line. There is a gasket on the pump flange when tightening the coupling bolts, should pay attention to making the volute liner higher than the pump flange, at the same time can not over tighten, to avoid damage to the gasket.

Use hands to turn the shaft in the direction of the rotation of the pump. The shaft should be able to drive the impeller and there should be no friction, otherwise, the gap between the impeller and frame plate liner and the gap between the impeller and the throat bush should be adjusted

Check the direction of rotation of the electric motor. Make sure the pump turn in the direction as labeled on the frame plate. Note that the pump must not turn in the reverse direction. Otherwise, the impeller may be screwed off the shaft and damage the pump.
In the direct drive, the shaft of the pump should be exactly co-centric with the shaft of the electric motor. For V-belt drive, the pump shaft and the motor shaft should be parallel. Adjust the position of the groove such that it is perpendicular to be a belt, so as to avoid violent vibration and wear and tear

At the suction pipe, a short removable pipe should be equipped, the length of which should be such that the cover plate and other wearing parts could be repaired easily by removing this pipe.

Check the shaft sealing systems. If the expeller ring has a grease cup, lubricants should be added via the grease cup.

Sludge pump running

Before starting the pump, first, open the shaft seal water to prevent the packing or mechanical seal from being burned due to heat generation. During the operation, the pressure and flow of the shaft seal water should be regularly checked to adjust the packing gland or replace the packing. To ensure that there is always a small amount of clean water through the shaft

Fully open the inlet valve;
Fill water into a pump (when the pump is in the flood suction no need to fill with water );
Adjust the outlet valve opening to 1/4;
Start the pump. when the speed is normal, can slowly open the outlet valve until completely open or meet the requirements of working conditions.

Check the bearing assembly regularly. If the bearing gets overheated when the operation is started, the pump should be switched off to let the bearing cool down, then switch on the pump again. When the bearing still gets severely overheated and the temperature keeps rising, the bearing assembly should be stripped and carefully examined to find out the reason. Usually, overheating is caused by excessive lubricant or impure lubricant. The lubrication should be a clean and appropriate amount. The grease should be added regularly.

The efficiency of the pump decrease as the gap between the impeller and throat bush increases. Thus the impeller should be moved forward regularly to ensure the gap is kept at an appropriate size. When the parts are worn such that the system requirement can not be met, the wearing parts should be replaced.

Stop the pump

Before shutting down the pump, if possible, the pump should be allowed to transport clean water for a while so as to clean the slurry inside the pump

Then close the inlet and outlet valves

The packing seal water must be open throughout the continuous operation cycle, which is to be activated during start-up, operation, parking, and re-operation. If it is a mechanical seal after the pump is stopped, it is necessary to continue to maintain the supply of seal water, and the mechanical seal can be stopped after it has cooled down


To make the pump safe operation, we must pay attention to the daily maintenance, maintenance should pay attention to several aspects

Maintenance of shaft sealing

For a packed gland seal pump the water pressure and water volume of flush seal water should be checked regularly. Make sure that there is always some clean water passing around the shaft. Adjust the gland assembly regularly. check the stuffing regularly and replace the stuffing if necessary. The pressure and flow rate of the sealing water should meet the standards stated. The expeller seal pump with grease cups should be filled with grease regularly to lubricate the internal packing

Adjusting the impeller

In order to ensure the efficient operation of the pump, the gap between the throat bush and the impeller should be adjusted regularly. The distance between the impeller and the throat bush should be kept at 0.5-1 mm in the metal liner pump. The gap between the impeller and liners should be kept the same in the rubber liner pump. To adjust the gap between liners and impeller, shut down the pump first. Lose the bolt which presses the bearing assembly tight. Tighten the nut on the adjusting screw to move the bearing assembly forward. At the same time, use hands to turn the shaft in the direction of the pump until the impeller and throat bush are next to each other. For metal liner pumps, loose the just tightened nuts half a circle and tighten backward. The gap between the impeller and throat bush is 0.5-1 mm. For rubber liner pumps, tighten the nut on the adjusting screw to move the bearing assembly forward, so that the impeller just touches the cover plate liner. Then move the bearing assembly backward until the impeller touches the frame plate liner insert. Measure the distance that the bearing assembly has been moved. Take half of this distance as the gap between impeller and cover plate liner and impeller and frame plate liner. Adjust the position of bearing assembly using an adjusting Screw to make sure that the gap between impeller and front and back liners are of the appropriate amount. After adjustment check, if the impeller operates correctly before starting the operation again.

Lubrication of the bearing

The service life of the pump will be longer if the bearing assembly is correctly assembled. the lubricant is of the right amount and the pump is regularly maintained.
Maintenance staff should check the bearing assembly and the amount of lubricant regularly. Usually, the pump should be maintained at least every 2 months. When the pump is in operation, lubricant should be added regularly. The frequency and amount of which depends on the speed of revolution, type of bearing, continuous work time, the number of times that the pump is shut down, ambient, temperature, etc.


The Pump that has not been used for a long time should be turned a quarter of a revolution every week to make sure that every part of the bearing evenly withstands the static load and external vibration.

The Frame Plate and Frame are used for a long time and the tensile strength is reduced. Check and replace them in time

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