AY type oil pumps are divided into single-stage, two-stage cantilever type, both-end support type and multi-stage pumps. The structural form is shown in Figures (1) ~ (7)

Shell part: Single-stage and two-stage pumps are composed of pump body and pump cover. Multi-stage pumps are composed of suction section, discharge section, middle section, etc. It bears all the working pressure of the pump, and the inlet and outlet directions are vertically upward. There is a shaft seal cavity (stuffing box) cast on the pump cover, and there is an optional water-cooling cavity jacket outside the shaft seal cavity.

The equipment of water-cooling jacket must be specially requested or used when the conveying medium is water with a temperature exceeding 66°C and a hydrocarbon temperature exceeding 120°C.

Rotor part: composed of impeller, shaft, sleeve, impeller nut, balance plate (drum) (referring to multi-stage pump). The axial force of the single-stage pump is mainly balanced by the impeller balance hole, the axial force of the two-stage pump is mainly balanced by the impeller itself, and the multi-stage pump is balanced by the balance plate (drum).

Bearing part: It consists of a bearing body and a rolling bearing or sliding bearing. It supports the rotor part of the pump and also bears the remaining axial force of the pump. The bearings are lubricated with thin oil. The bearing body can choose air cooling (t≤120℃), fan cooling (t=120~260℃), or water cooling (t=260~420℃) according to the temperature of the conveying medium.

Transmission part: The pump and the prime mover are connected by a flexible diaphragm type extended coupling component. During maintenance, remove the middle extended coupling first, and then the pump can be replaced or inspected without moving the prime mover.

Sealing part: According to the usage conditions, the shaft seal cavity can be filled with packing seal or mechanical seal.

Pump rotation: Counterclockwise rotation when viewed from the coupling end toward the pump.

50AYII60x2B 150AYIII67x9 250AYSII150C

50, 150, 250 – suction port diameter (mm)

A——The first renovation design

Y——Centrifugal oil pump

S——The first stage impeller is double suction

I, II, III——Material codes of the pump flow parts

Class I is HT250, Class II is ZG230-450, Class III is ZG1Cr13Ni

60, 67, 150——Pump single-stage lift (m)

2. 9——Number of pump stages

B, C——impeller cutting times, the order is represented by A, B, C…

Cooling water piping system

In order for the pump to work normally, the shaft seal cavity, bearings and pump bracket must be cooled in different forms according to the working conditions. Generally, the pump is equipped with only the inlet and outlet pipe joints.

The minimum nominal diameter of the cooling water pipeline should be φ15.

The cooling water volume of each pipe is recommended to be 0.3~0.7m3/h, and its pressure is 0.2~0.3MPa.

Seal flush piping system.

Shaft seals are selected according to different pump delivery media and working conditions such as temperature and pressure. If the user does not specifically request it, it will be assembled by the pump factory.

The flushing pressure and oil volume of the sealing oil are considered by the pump manufacturer. When external supply is required, the values are provided. The oil sealing volume of each pump is as follows:

The pressure of the sealing oil is generally 0.07~0.01MPa higher than the pressure of the sealing chamber. If the conveying medium is easily vaporized, it should be 0.175~0.2MPa higher than the vaporization pressure.

The height, length, and diameter of the pump suction pipe should meet the design requirements and ensure that the allowable cavitation margin of the pump is not exceeded during operation.

The suction and discharge pipes should have pipe racks, and the pump body is not allowed to bear the external load of the pipes.

The suction pipeline should be short and straight. The diameter of the pipe should be 1-2 steps larger than the diameter of the pump suction inlet. At the same time, it should be connected by an eccentric shrinkage reducing pipe. The pump suction pipeline should have a bending radius as large as possible.

Correct the concentricity of the pump shaft and the prime mover shaft. The deviation on the outer circle of the two half couplings is allowed to be ≤ 0.08mm, and the end face deviation is ≤ 0.05mm.

After the pipeline is installed and the rotation direction of the prime mover is determined, reinstall the coupling.

To lubricate the bearing body, the recommended bearing lubricant is No. 22 or No. 30 turbine oil.

Turn on the cooling water, and if the seal is flushed externally, seal oil should be supplied.

Open the suction valve and discharge valve, fill the pump with liquid, and then close the discharge valve.

Turn on the power, turn on the car (stop immediately after driving), and observe whether the rotation direction of the pump shaft is counterclockwise.

When transporting hot oil, it must be preheated evenly before starting the machine. Preheating is performed by using the transported hot oil to continuously pass through the inside of the shell. The recommended preheating speed is 40℃-50℃/h.

After starting, open the discharge valve of the pump immediately. Never allow the discharge valve of the pump to be closed for a long time to prevent damage to the pump caused by overheating.

The motor load current cannot exceed the motor’s rated current.

After operation, generally observe whether the pressure and current of the pump are within the normal range of use. The pump should not be continuously operated below the minimum continuous stable flow rate.

If the pump does not give a minimum continuous stable flow, it should not operate continuously at less than 30% of the design flow.

The gate valve on the suction pipe cannot be used to adjust the flow to avoid cavitation.

Check the vibration during normal operation. The unfiltered vibration measured on the rolling bearing body should not exceed the peak speed of 7.6mm/S.

After the pump has reached operating temperature and pressure, check the pump unit again and readjust (fine-tune) the pump unit if necessary.

After running for about 24 hours, drill a taper pin on the horizontal supporting surface of the pump body. If the base of the prime mover allows, a tapered pin must also be drilled, the diameter of which depends on the neutral position.

Regularly check the heating of the bearings. The rolling bearing temperature should not exceed 80℃, and the sliding bearing part should not exceed 65℃.

The oil cup must be checked every 8 hours during shift change to see if the oil level in the oil cup is normal.

It is recommended to drain and flush the oil every six months, and then add new oil. Generally, this is done in spring and autumn. Frequent oil changes are also necessary for sites in humid, desert areas, with severe climate changes, and in the open air.

For the spare pump on the device, the rotor component should be rotated regularly. It is recommended to rotate it once a week, about 360°+90° each time, to prevent deformation and maintain the lubricating oil film of the bearing lubricant.

The high-temperature backup pump on the device must be maintained at a certain temperature to prepare for use.

Check the wear of the housing sealing ring, impeller sealing ring, throat bushing, shaft sleeve, guide vane sleeve, bearing, impeller, moving ring and static ring of mechanical seal, etc.

Clean the dirt and blockage in the cooling water, sealing oil pipelines and water-cooling chamber.

Check and adjust shaft bending and rotor runout.

Check the O-ring seal, sleeve gasket, pump cover gasket, and mechanical seal gland gasket for defects and scratches.

Check the concentricity of the coupling halves.

The impeller nut of the cantilever pump is connected to the shaft with a left buckle, and the eccentricity is fixed with GB80-85 M6 hexagonal socket screws to prevent loosening.

All rubber O-rings must be prevented from sharp corners and burrs during assembly. At the same time, after using it once, under normal circumstances, it cannot be used a second time.

There should be no signs of cracks on the bushing pad, especially be careful not to forget to install it.

The thrust ball bearings are type 7300 produced by SKF and are installed or replaced in back-to-back pairs.

The bearing is heated to 80-95 and installed on the shaft. Then, keep the axial deflection between the rear bearing cap and the thrust ball bearing between 0.13-0.25mm and adjust it with its gland pad.

Before reassembly, clamp the pump shaft on the lathe, and use a dial indicator to check that the concentricity of key parts of the shaft (such as the sleeve, bearing, impeller…) does not exceed 0.05mm.

For details on the disassembly and assembly of mechanical seals and precautions, please refer to the “Mechanical Seal Installation and Operation Instructions”

If the sealing ring gap doubles (resulting in a decrease in efficiency and an increase in power) or the current increases too much, replace it.

Grooves appear on the outer surface of the packing sleeve, and there are scratches on the sealing surfaces of the dynamic and static rings of the mechanical seal, especially radial scratches. In mild cases, they should be repaired by grinding, and in severe cases, replace them.