How to maintain the centrifugal pump properly

The centrifugal sand pump is used as the main equipment for conveying mud in the mud solids control system. It can be used as a supply pump of desander, desilter, and it can also provide power for the slurry and inject the slurry into the mud pump. It is a necessary equipment in the solid control system.

Sand pump is mainly used to match the circulating solids control system of oilfield drilling rigs. Its function is to provide drilling fluid with a certain displacement and pressure for desanders, desilters, slurry mixing devices, etc., to ensure that these equipment work efficiently. Therefore, the maintenance of the sand pump can increase the service life and improve the efficiency of use.

Detailed description of each step in the centrifugal pump maintenance process:

1.Disassembly:

Remove the packing gland, remove the pump casing, remove the impeller, first remove the impeller nut with a wrench. Pay attention to knocking the spoke ribs on the back of the impeller with a wooden spacer and a hammer, then exit the impeller, remove the guard plate, exit the auxiliary impeller, unload the stuffing box, and exit the polyurethane skeleton oil seal, spacer ring and packing from the packing cavity. Exit the bushing. If the bushing is too tight, use a wedge block to knock its tail to loosen it. Remove the bearing gland, remove the lock nut and lock washer, pad the shaft end with a copper rod or wooden block, and remove the shaft and bearing components from the bracket from left to right.

2. Check:

Impeller inspection, when severe cavitation, transitional corrosion, abrasion, or damage, the impeller is required to be replaced. In shaft inspection, if the radial runout exceeds 0.05mm, the oil seal position is severely scratched, and the threads, grooves, steps and other surfaces on the shaft are damaged, the shaft needs to be repaired. If it cannot be repaired, the shaft should be replaced. Check the shaft sleeve. When the surface is rough and damaged, replace the shaft sleeve. The removed oil seal must be replaced. Ball bearing inspection, for excessive wear, running tight, loose or noisy bearings must be replaced (new bearings can only be opened when they are replaced, the replaced bearings must be the same type and size as the original pump bearings). In the inspection of O-rings, the O-rings that are generally disassembled should be replaced. For other sealing gaskets, they can be reused as long as they are not damaged.

3. Assembly:

All parts must be cleaned before assembling, especially the threads, bearings and bearing lubrication parts, they must be cleaned carefully, and some rough parts should be polished with fine gauze. Install the power end thrust bearing first. The two bearings should be installed back to back. After tightening the lock nut, the lock washer must be buckled, and the lock nut must be tightened with a torque. When installing the shaft sleeve, apply a thin layer of anti-friction agent on the shaft and install the stuffing box. Install the auxiliary impeller. Install the impeller, the gap between the back of the impeller and the guard plate is 0.6mm, and the packing gland should not be tightened too tightly, otherwise the packing may be burned out when the pump is running. The assembly sequence should be carried out in the reverse direction of disassembly. After assembly, the shaft should be flexibly rotated by hand, and there should be no jamming in all parts.

Xi'an HL Petroleum produces oilfield centrifugal pumps, sand pumps, shear pumps, spray pumps, screw pumps, and slurry pumps, welcome to send inquiry to sales@hlsolidscontrol.com if you want to know more about it.