I. Purpose and Scope of Application of the Pump
The ZJ series slurry pumps are a new type of high-efficiency, energy-saving, abrasion-resistant pump. In hydraulic design, structural design and the abrasive-resistant materials used, this series comprehensively incorporates the advantages of similar products at home and abroad together with innovations, and features high efficiency and energy savings, low vibration, low noise, reliable operation, long service life and easy maintenance. The overall performance of the pumps ranks among the leading levels in China, and the efficiency figures of most pumps reach the advanced international level. They can be widely used in the electric power, metallurgy, coal, and building materials industries to convey slurries containing solid particles, for example hydraulic ash removal in thermal power plants, ore slurry transfer in metallurgical concentrators, and coal slurry and dense-medium transfer in coal preparation plants. The maximum permissible conveyed slurry concentration by weight Cw is: 45% for ash (slag) slurry and coal slurry; 60% for ore slurry and dense medium.
II. Type, Structural Features and Model Designation of the Pump
The ZJ series slurry pumps fall into two types: the ZJ type, a horizontal, axial-suction, single-stage, single-suction centrifugal slurry pump; and the ZJL type, a vertical, axial-suction, single-stage, single-suction centrifugal slurry pump.
Structural features and model designation of the ZJ slurry pump
(1) Structural features of the ZJ slurry pump
① Pump head section
The pump head section of the ZJ slurry pump comprises the casing, the impeller and the shaft seal device. The pump head is bolted to the frame. As required, the discharge outlet position of the pump can be installed and used at eight different angles rotated at 45° intervals.
The casing of the ZJ slurry pump is of double-shell construction. The outer shell is a metal casing (front casing, rear casing), usually made of HT200 or QT500-7; the inner shell may be made of high-chrome alloy cast iron (comprising the volute liner, throat bush and frame plate liner), or of rubber (comprising the front volute liner and the rear volute liner).
The impeller consists of a front shroud, a back shroud, blades and back blades. The blades are twisted blades, usually 3-6 in number. The back blades are arranged on the outer sides of the front and back shrouds, usually 8 in number. The impeller is made of high-chrome alloy cast iron, and the impeller is threaded onto the shaft.
The shaft seal device is available in three types: expeller + packing combination seal, packing seal and mechanical seal, see Fig. 1.
The expeller + packing combination seal type consists of the stuffing box, expeller, lantern ring, packing, gland and shaft sleeve assembly, see item 5 in Fig. 1.
The packing seal type consists of the stuffing box, spacer sleeve, lantern ring, packing, gland and shaft sleeve, see item 5a in Fig. 1.
The mechanical seal type consists of the stuffing box, spacer sleeve, mechanical seal, gland and shaft sleeve, see item 5b in Fig. 1.
② Frame section
The frame section is available in two constructions: horizontally split and cartridge.
The horizontally split frame comes in two versions: oil lubrication and grease lubrication. The oil-lubricated frame mainly consists of the frame body, frame cover, shaft, bearing housing, bearings, bearing cover, spacer sleeve, nuts, oil seals, water deflector, dismantling ring and other parts, see Fig. 1. Pumps of 150ZJ and larger are additionally fitted with a water cooling device. The main differences between the grease-lubricated frame and the oil-lubricated frame are: an inserted bearing cover and grease cups are added, and the water cooling device is omitted, see item 16a in Fig. 1 (continued).
The cartridge frame is always grease-lubricated, and mainly consists of the frame body, bearing body, shaft, bearings, bearing top sleeve, bearing cover, oil seals, water deflector, dismantling ring and other parts, see item 16b in Fig. 1 (continued). The cartridge frame is only applicable to pump models of 200ZJ and below with relatively low power; at present only three specifications are available: T200ZJ-I-A70, T200ZJ-I-A60 and T150ZJ-I-A60.
For the specific structure of the ZJ pump, see Fig. 1.
Model designation of the ZJ slurry pump
T 200 ZJ __ I __ A 60
Nominal impeller diameter, mm
Number of impeller blades: A is 5, B is
4, C is 3, F is 6, G is 7, H is 8.
Applicable number of pump stages: I is one stage, II is two stages;
ZJ slurry pump
Pump outlet diameter, mm
T denotes a cartridge frame; horizontally split frames are not marked.
2. Structural features and model designation of the ZJL slurry pump
(1) Structural features of the ZJL slurry pump
The ZJL slurry pump mainly consists of the impeller, volute liner, frame plate liner, shaft sleeve, support bracket, support plate, shaft, bearings, bearing body and other parts. The impeller, volute liner and frame plate liner are made of high-chrome alloy cast iron; the impeller is threaded onto the shaft; the volute liner, support bracket and bearing body are bolted together. The pump shaft can be driven directly by the motor through a coupling, or by belt drive. The bearings of the ZJL slurry pump are grease-lubricated. The pumps of this series are of seal-less construction (without a shaft seal).
For the specific structure of the ZJL slurry pump, see Fig. 2.
(2) Model designation of the ZJL slurry pump
80 ZJL __ 36
Nominal impeller diameter, mm
ZJL vertical slurry pump
Pump outlet diameter, mm
III. Lifting, Installation, Adjustment and Test Run of the Pump
1. Lifting
When lifting a pump packed in a packing case, fasten the wire ropes according to the markings on the case. During hoisting, the bottom or sides of the case must not be subjected to impact or severe vibration; the case must not be tilted excessively, must not be placed on objects with sharp edges, and must never be placed upside down.
When lifting a pump without a packing case, comply with the following requirements.
(1) When lifting a horizontal pump without a base plate, or with a separate base plate only, the lifting center shall be at the square hole on the side of the frame close to the pump head; the wire rope shall pass through this point and extend vertically upward to the crane hook. To keep the pump in balance, an auxiliary lifting wire rope shall be rigged between the eyebolt on the casing and the crane hook. The eyebolts on the frame cover and on the front and rear casings are provided for removing the frame cover or the front and rear casings only, and must not be used alone for lifting the complete pump, lest an accident occur.
(2) When lifting a horizontal pump with a motor on a common base plate, the lifting center of gravity is at the square hole of the frame close to the coupling; the wire rope passes through this point and extends vertically upward to the crane hook to keep balance; auxiliary lifting wire ropes must also be rigged between the eyebolt above the casing, the motor eyebolt and the crane hook.
(3) Horizontal pump units with intermediate variable-speed devices such as fluid couplings shall be lifted in separate parts.
(4) Soft padding shall be added where the wire rope contacts the casing, to protect the pump appearance from damage and to prevent the wire rope from being cut.
2. Installation
(1) Checks before installation
The pump has been inspected and tested before leaving the factory; to ensure that it remains in good working condition, it must be installed correctly. Before installation, first check the model and parameters of the equipment against the packing list, and check that the parts are complete and intact and that the accompanying technical documents and quality certificates are complete. After verification, read the relevant technical documents in detail — in particular this ZJ Series Slurry Pump Operating Manual — and master the relevant technical requirements and operating essentials before carrying out the installation. Never work blindly.
(2) Installation and alignment of the pump
Horizontal pump units shall be installed using the second-grouting method. After installation, the centerline of the unit shall coincide with the centerline of the foundation; the deviation of the unit center height from the design value shall be no greater than ±2 mm, and the permissible levelness deviation of the unit is 0.1/1000.
For pump units driven directly through a coupling, the concentricity of the unit is generally ensured by coupling alignment. There are two methods of coupling alignment:
One method uses a knife-edge straightedge in conjunction with a feeler gauge. The straightedge is used to align the coupling rims, ensuring that each pair of coupling halves is flush in every direction, with a maximum error δ of no greater than 0.10 mm [Fig. 3, (a)]. The feeler gauge is used to check the gap between each pair of coupling halves, with a maximum error Δ (Δ = δ1 - δ2) of no greater than 0.10 mm [see Fig. 3, (b)].
The other method is to align the coupling with a magnetic dial indicator together with a feeler gauge. Clamp the magnetic dial indicator on the rim of one coupling half and rotate the shaft; place the indicator tip on the rim of the opposite coupling half; the observed runout of the dial indicator shall be no greater than 0.15 mm [see Fig. 3, (c)]. The coupling gap is measured with a feeler gauge, and its maximum error shall be no greater than 0.10 mm [see Fig. 3, (b)].
For belt-driven pump units, the parallelism between the pump shaft and the motor shaft shall be ensured, usually by aligning the belt pulleys. Where the center distance is small, alignment can be done by holding a straightedge flat against the pulley end faces. Where the center distance is large, alignment can be done with a stretched wire against the pulley end faces, as shown in Fig. 4.
(3) Configuration and requirements of the pump inlet and outlet piping
① Suction line
Suction pipe diameter: the suction pipe diameter shall be the same as, or slightly larger than, the pump inlet diameter; the principle is both to avoid cavitation of the pump and to prevent the slurry from settling out in the pipeline.
Inlet gate valve: to facilitate pump maintenance, a gate valve shall be installed at the pump inlet, with a diameter the same as the suction pipe diameter. An expansion joint shall be installed between the pump inlet and the suction pipe to facilitate removal and refitting of the pump.
② Discharge line
Discharge pipe diameter: the discharge pipe diameter is related to the slurry properties and the settling velocity; in general, the discharge pipe diameter is equal to, or slightly larger than, the pump outlet diameter.
Outlet gate valve: the outlet gate valve shall be the same size as the discharge pipe
Pressure gauge: located on the straight pipe section between the pump outlet and the first valve.
③ Notes on pump piping configuration
The piping layout is shown in Fig. 5:
The pipe diameter shall be determined by considering the system resistance, the critical settling velocity of the slurry and other overall factors. The suction pipe should be as short and straight as possible. At the pump inlet, it is best to provide a straight pipe section of the same diameter as the inlet, with a length of not less than 3 times the inlet diameter. The flow velocity in the suction pipe is generally 1.5-3.0 m/s, depending on the settling velocity of the slurry being conveyed.
With the elevated layout, the pump suction line shall be arranged so as to avoid air pockets; a reducer with a horizontal top generatrix is recommended, as shown in Fig. 6.
When the flow is regulated with a valve, the regulating valve shall be installed at the pump outlet; regulating the flow with a valve on the inlet line is not allowed, so as to avoid cavitation.
(4) Piping configuration and requirements for shaft-seal water and cooling water
The shaft-seal water and cooling water piping shall be configured according to the schematic diagram Fig. 7; no cooling water is added for grease-lubricated frames. When grease-lubricated packing is used, no shaft-seal water is added.
The pressure and flow of the shaft-seal water shall be as given in Table 1. Table 1
The cooling water pressure is 0.05-0.2 MPa, and the cooling water flow is 1-3 m3/h.
The connection sizes for shaft-seal water and cooling water are given in Table 2.
(5) Requirements for filling the packing (packing rope)
① Packing material and selection
Generally, when the working pressure of the pump is below 0.5 MPa, tallowed cotton packing or oil-impregnated asbestos packing may be used; when the working pressure of the pump is above 0.5 MPa, polytetrafluoroethylene packing or carbon-fiber packing impregnated with polytetrafluoroethylene may be used.
② Packing sizes are given in Table 2.
③ Packing filling requirements: the packing size must conform to the dimensional requirements of the packing chamber, and the joints of two adjacent rings of packing shall be staggered by 120°.
(6) Mechanical seal
The mechanical seal is a face seal, featuring zero leakage and low power consumption.
The following points require particular attention when a mechanical seal is used on a slurry pump:
① The mechanical seals adopted by our works are generally balanced, double-face mechanical seals dedicated to slurry pumps, supplied with cooling water nipples and a pressure gauge.
② The mechanical seals adopted by our works are manufactured for our works by specialized mechanical seal manufacturers, and have already been installed and commissioned before delivery; users need not commission them again.
③ The mechanical seal section has two exposed pipe connections, namely the shaft-seal water inlet and outlet; the one on the same side as the pump outlet is the water outlet, and the one on the other side is the water inlet.
④ Before a pump fitted with a mechanical seal is put into service, the shaft-seal water must be turned on first; the shaft-seal water may be shut off only 3 minutes after the pump is stopped.
Table 2
G1/4"
⑤ When mechanical seal spare parts are supplied to the user, the manufacturer generally fits the mechanical seal into the stuffing box and supplies it as a complete assembly.
⑥ If a pump fitted with a mechanical seal, or mechanical seal spare parts, is to be out of use for a long time, the mechanical seal section shall be filled completely with No. 46 machine oil, to prevent the mechanical seal components from rusting and the internal rubber parts from failing.
(7) Requirements for filling lubricating oil
For oil-lubricated frames, fill No. 32 (winter) or No. 46 (summer) machine oil up to the oil level mark before start-up.
Never start the pump without oil!
Grease-lubricated frames shall be filled with No. 2 or No. 3 lithium-based grease.
3. Adjustment of the pump
After installation and alignment, the pump shall be checked and adjusted.
(1) Checking and adjusting the clearance between the impeller and the throat bush, see Chapter V.
(2) Adjusting the motor rotation direction
The motor rotation direction shall ensure that the pump rotates in the specified direction and does not rotate in reverse; otherwise the impeller may unscrew from the shaft or other parts may be damaged.
The motor rotation direction shall be adjusted with the motor completely disengaged from the pump (i.e. without the coupling pins or the belts fitted); the motor may be connected to the pump only after the rotation direction has been confirmed to meet the requirement. Never start the motor blindly.
(3) Adjusting the transmission
For drives using flexible pin couplings, fit the pins and the guard properly.
For belt drives, fit the belts, adjust the tension so that every belt is tensioned equally, and fit the guard properly.
(4) For drives using variable-speed devices, make the adjustment in accordance with the requirements of the corresponding manual.
(5) Adjusting the fasteners.
All fasteners shall be re-tightened once with a wrench.
(6) Remove the tools and sundries placed on the unit, to prevent accidents during pump operation.
4. Test run of the pump
After the pump unit has been installed and adjusted, it can be test-run. Where conditions permit, the user should first test-run with clean water, and convey slurry only after operation is normal.
(1) Starting a single-stage pump
① Turn on the shaft-seal water and cooling water, and adjust the pressures to the specified values;
② Fully open the inlet valve;
③ Open the priming valve to fill the pump with water (pumps under flooded suction need no priming);
④ Adjust the outlet valve opening to 1/4;
⑤ Start the unit. Once the speed is normal, turn on the outlet pressure gauge; if the pressure is normal and stable, the outlet valve may be slowly opened until it is fully open or the duty requirement is satisfied.
Note: starting the pump with the outlet valve fully open will overload the motor; controlling the flow by throttling the inlet valve will cause cavitation of the pump, and this must be avoided!
(2) Starting pumps in series
The discharge pipelines of pumps in series are all fairly long, and the pipeline head in the design calculation is based on operation with the whole pipeline filled with slurry. At start-up the pipeline is not yet filled with slurry; if the valves are fully opened, the pipeline head is very low and the instantaneous pump flow tends toward large flow, causing motor overload, or cavitation and vibration of the pump, and leading to failure.
Therefore it is advisable to start according to the following steps:
① Close the outlet valve and fully open the inlet valve;
② Turn on the shaft-seal water and cooling water, and adjust the pressures to the specified values;
③ Open the priming valve to fill the pump with water (for pumps under flooded suction, open the inlet valve);
④ Start the first-stage pump and gradually open the outlet valve to 1/i (i is the number of stages in series).
⑤ When the slurry is estimated to have filled 1/i of the pipeline, start the second pump and gradually open the outlet valve to 2/i.
⑥ When the slurry is estimated to have filled 2/i of the pipeline, start the third-stage pump and gradually open the outlet valve to 3/i.
⑦ And so on, until the slurry fills the entire pipeline and operation is normal.
(3) Points to note when starting the pump:
① If the packing has been compressed too tightly, the packing will heat up and smoke once the pump rotates; loosen the gland nuts so that the shaft-seal water leaks, then tighten them again slowly until leakage is by dripping/seepage only.
② After normal operation, the following items shall be observed:
Whether the flow and head of the pump (outlet and inlet pressures) are stable and meet the process requirements;
Whether the current is stable;
Whether the unit makes any abnormal sound, and whether the noise and vibration are excessive;
Whether the shaft seal leakage is normal (dripping);
The bearing temperature rise is 35 °C, and the maximum temperature shall be no greater than 75 °C.
(4) Stopping the pump
① Before stopping the pump, clean water shall be pumped for 30 minutes to flush the slurry out of the pump and the pipelines.
② Close the outlet valve of the last-stage pump.
③ Stop the pumps stage by stage from the last stage to the first stage, and shut off the corresponding shaft-seal water and cooling water.
④ Close the inlet valve of the first-stage pump.
Note: it is absolutely not permissible to stop the pumps of all stages simultaneously while the outlet valves are fully open; otherwise water hammer may easily form and destroy the pump or the pipe fittings.
IV. Common Faults and Remedies
The common faults of the pump and their remedies are given in Table 2. Table 2
Reassemble or tighten.
V. Maintenance, Disassembly and Assembly of the Pump
To ensure the safe and reliable operation of the ZJ series slurry pumps and to give full play to the capability of the equipment, daily maintenance and the use of correct repair, disassembly and assembly methods are very important. For this reason, based on the characteristics of the ZJ series slurry pumps, we put forward the following maintenance and repair requirements for users' reference.
(I) Maintenance
ZJ series slurry pumps are completely adjusted before leaving the factory; within 6 months of delivery, pumps that have not been used need not be disassembled for inspection. It is sufficient to check whether rotation is free, the corrosion condition and the oil filling condition; the packing must be filled before use.
1. Keep the equipment clean, dry, free of oil stains, and leak-free.
2. Check the oil level in the frame daily; the correct oil level is near the oil level mark, and shall not deviate by more than ±2 mm.
3. Regularly check the pump for abnormal sounds, vibration and leakage during operation, and handle any problems found promptly.
4. It is strictly forbidden to run the pump in a suction-starved (dry-running) condition; running in this condition not only causes violent vibration but also affects the pump life. Pay special attention to this.
5. It is strictly forbidden for metal objects, solids larger than the pump's permissible passage size, and flexible materials such as rubber sheet, cotton yarn and plastic sheeting to enter the pump, to avoid damaging the wetted parts and blocking the impeller passages so that the pump cannot work normally.
6. Regularly check whether the pressure and flow of the shaft-seal water and cooling water are appropriate; this can be done by checking the opening of the shaft-seal water pipe valve or by measuring the stuffing box temperature — a high temperature indicates an insufficient water supply. For pumps with grease-lubricated packing, grease should be added once or twice a day at set times to ensure the packing stays in a good lubricated state.
7. Check the shaft-seal water leakage regularly; when the leakage increases, adjust the packing gland bolts, and replace the packing promptly when replacement is needed.
8. PTFE-impregnated carbon-fiber packing or tallowed cotton packing is recommended; where the working pressure is no greater than 0.5 MPa, asbestos packing may be used.
The packing shall be filled strictly in accordance with the following requirements:
(1) The packing length is determined by the developed length of the shaft sleeve circumference; when each ring is packed, the cuts shall be staggered by 120°.
(2) After packing, a water-fed trial run must be carried out, during which the gland bolts are adjusted in detail; the optimum state is leakage in drops rather than in a stream. The filling of the packing is very important: it affects not only the quality of the seal but also the performance of the pump, and deserves full attention.
9. To ensure efficient operation of the pump, the clearance between the impeller and the throat bush must be adjusted periodically (after a period of use, when the current slowly decreases under unchanged operating conditions), keeping it within 0.75-1.00 mm.
The adjustment steps are as follows:
(1) For pumps with horizontally split frames
The clearance between the impeller and the throat bush should be 0.75-1.00 mm, generally adjusted before delivery; if this clearance is found not to meet the requirement, adjust it, and if a problem is found during operation, stop the pump and adjust it as well.
Pumps with horizontally split frames are adjusted by the following method:
① Loosen the frame cover clamp nuts;
② Loosen the bearing housing adjusting screws;
③ Evenly tighten the bearing housing clamp nuts so that the rotor assembly moves toward the pump head, turning the shaft by hand while tightening until it cannot be turned. Note: the shaft shall be turned in the working direction of rotation of the pump.
④ Measure the gap δ = a between the bearing housing flange and the frame end face with a feeler gauge; at this point the clearance between the impeller and the throat bush is 0.
⑤ Loosen the bearing housing clamp nuts;
⑥ Evenly tighten the bearing housing adjusting screws so that the rotor assembly moves toward the motor, checking the gap with a feeler gauge until δ = a + (0.75-1.00) mm (larger pumps take the larger value); note that the gap shall be even and consistent;
⑦ Tighten the bearing housing clamp nuts so that the axial position of the rotor is completely fixed.
(2) For pumps with cartridge frames (see item 16b in Fig. 1 (continued))
The clearance between the impeller and the throat bush should be 0.75-1.00 mm, generally adjusted before delivery. If this clearance is found not to meet the requirement, adjust it by the following method:
① Loosen the frame clamp plate nuts;
② Adjust the lead screws so that the rotor moves forward, turning the shaft by hand while adjusting until it cannot be turned; note: the shaft shall be turned in the same direction as the rotation of the pump;
③ Scribe a straight line with a marking scriber at the joint between the frame and the cartridge as a reference mark;
④ Adjust the lead screw nuts so that the rotor assembly moves back by 0.75-1.00 mm (larger pumps take the larger value), and lock the adjusting nuts so that the axial position of the rotor is fixed;
⑤ Tighten the frame clamp plate nuts.
10. Regularly check the bearing temperature; the maximum temperature shall not exceed 75 °C.
11. After the pump has run continuously for 800 hours, the lubricating oil shall be changed completely once.
12. Standby pumps shall be rotated 1/4 turn every week, so that the shaft carries the static load and external vibration evenly.
13. If the shutdown period is long, flush the deposits out of the pump with backwash water before restarting.
14. Regularly check the inlet and outlet piping system supports for looseness; ensure the supports are firm and reliable, and that the casing is not subjected to supporting forces.
15. Regularly check how firmly the pump is fastened to the foundation; the connections shall be firm and reliable.
16. Special attention: for newly installed or newly overhauled pumps, always verify the motor rotation direction first, and only then fit the coupling pins. For belt drives, that is, only after the rotation direction has been verified, install the transmission belts; never allow the motor to drive the pump in reverse. However, reverse rotation of the pump caused by backflow of liquid in the pipe while the motor is de-energized is permitted; note that when the static head is especially large (≥80 m), backflow of return water should also be prevented, to control sudden reverse rotation of the pump.
17. Before starting the pump, turn on the shaft-seal water and cooling water first, then start the pump; after stopping the pump, wait 15 minutes before the shaft-seal water and cooling water may be shut off.
(II) Disassembly, inspection and assembly
Before assembly, all parts of the pump shall be comprehensively inspected and cleaned; check whether the parts conform to the operating instructions, and any parts that are worn or damaged must be replaced with new parts (or repaired) before assembly can proceed.
Assembly sequence and basic assembly requirements:
1. Assembly of the rotor assembly
The bearings used in the slurry pumps are generally domestically made bearings; the lubrication system uses oil (except for the 200ZJ-70, 200ZJ-60 and 150ZJ-60 pumps, which are available in both oil-lubricated and grease-lubricated versions); if the user has special requirements, the selection can be made according to those requirements.
(1) Notes on bearing fitting
① Only qualified bearings may be used;
② Check the bearing bore, outside diameter and width, the parallelism of both end faces of the raceway and the surface roughness, as well as defects such as corrosion and spots, and whether rotation is free;
③ For angular contact bearings and double-row self-aligning bearings, check the bearing clearance of each, locate the center of the ball raceway, and decide whether to add shims according to whether the inner ring sits high or low relative to the outer ring; the shim thickness is determined so as to ensure the standard bearing clearance.
④ When fitting separable bearings (with separate inner and outer rings), they must be installed according to the alignment marks on the inner and outer rings, and must not be mixed up;
⑤ For bearings that can be fitted turned around, fit the numbered end facing outward during assembly, for easy identification.
(2) Shaft fitting
① To avoid seizure with the mating surfaces, apply a layer of lubricating oil to the mounting surfaces before assembly, and protect the oil holes from damage.
② The bearings are fitted by the hot-fitting method: place the bearing in a heating tank filled with machine oil and heat it together with the oil to 80-100 °C; its mating surfaces shall be fully immersed in the oil; a thermometer shall be placed in the oil tank, and the temperature shall be strictly controlled not to exceed 100 °C. After hot fitting, allow the bearing to cool naturally; sudden cooling is not permitted, to avoid damage or deformation of the parts.
a. Fit the rear bearing first, then fit the spacer sleeve and the round nut and tighten them against the bearing.
b. Check whether the bearing is tight against the shaft shoulder and whether movement is free and smooth. Then fit the bearing housing. The bearing housing is also fitted by the hot-fitting method, with the same requirements as above.
c. Fit the front bearing last, with the same requirements as above.
d. Fit the seals on the bearing housing.
e. The other parts of the shaft section are installed in sequence according to the assembly drawing after the main shaft assembly has been fitted to the frame.
2. Assembly of the frame section:
First clean out all dirt from the oil sumps of the frame cover and frame body, and wipe the bearing bore clean.
(1) After the joint surfaces of the frame body and the frame cover have been cleaned, determine the thickness of the paper gasket to be added so that the upper and lower halves of the bearing bore conform to the drawing tolerances, within a permissible range of ±0.015 mm (use no more than three layers of gaskets when adjusting the thickness). Apply sealing compound evenly over the frame joint, place the gasket on the frame body, and tighten the studs.
(2) Fit the M16×1.5 hexagon oil sump plug and the oil level gauge, and scribe a 0.2-0.5 mm horizontal line through the center of the oil gauge plate and paint it red, to indicate the oil level.
(3) Fit the oil sump cooler assembly and the water-cooling chamber cover (with a 2 mm rubber gasket under the cover; note: some pumps do not have this cover).
(4) Fitting the shaft assembly to the frame
Lift both ends of the main shaft, and load the main shaft assembly into the mating bore of the frame; lift the frame cover, apply oil-resistant sealing compound to the kraft paper gasket on the frame joint face, and close the frame cover. The gap between the inner end face of the bearing housing flange and the frame end face shall be left at 3 mm initially. Drive in the pins and tighten the bolts.
(5) Fit the oil seal into the front bearing cover, add a kraft paper gasket, mount it on the shaft and connect it to the frame with bolts.
(6) Check the gap dimension between the spigot of the rear bearing cover and the spigot of the bearing housing; machine the height of the cover spigot, or use the shim method, to ensure a 0.05-0.10 mm gap is left between the cover and the bearing. Once this is done, fit the oil seal into the rear bearing cover, add a kraft paper gasket, mount it on the shaft, and connect it to the bearing housing with bolts.
(7) Fit the water deflector and the dismantling ring. When fitting the dismantling ring, a small amount of grease must be added into the bolt holes, and the dismantling ring must press the water deflector tight.
(8) Fit the adjusting bolts and set screws on the bearing housing.
(9) Mount a magnetic dial indicator on the shaft, and check the concentricity and perpendicularity of the semicircular locating holes and the end face (where the frame is joined to the rear casing) with respect to the center of shaft rotation; neither may exceed 0.25 mm.
3. Installation of the rear casing and frame plate liner section
(1) Mount the frame plate liner on the frame (note: during major overhaul it is recommended not to remove the rear casing from the frame).
(2) Fit the seal ring onto the shaft sleeve and mount it on the shaft, then fit the packing gland and the lantern ring onto the shaft sleeve.
(3) Install the stuffing box and fit the seal ring into the groove, fit the expeller seal ring and mount the expeller.
(4) First fit the frame plate liner studs; lift the frame plate liner with lifting tools, mount it on the rear casing, and tighten the bolts. After installation, measure whether the gap between the bore of the frame plate liner and the hub of the expeller is even, and turn the shaft by hand to check for any rubbing.
4. Installing the impeller and volute liner
(1) Apply grease to the "T" thread of the impeller, screw the impeller onto the shaft, tighten it, and compress the expeller.
(2) Fit the frame plate liner seal ring.
(3) Lift the volute liner with the volute liner lifting tool, mount it on the frame plate liner, fit the casing connecting bolts and the clamp plates, and, after adjusting the distance from the top face of the volute liner discharge outlet to the top face of the rear casing discharge outlet to 5 mm, clamp the volute liner.
5. Installation of the front casing and throat bush section
(1) Raise the front casing on blocks and lay it flat on the ground; fit the studs to the throat bush, lift it with lifting tools into the front casing, and fasten it to the front casing.
(2) Fit the throat bush seal ring and the front casing eyebolts.
(3) Lift the front casing together with the throat bush section, push the tapered outer circle of the throat bush into the tapered bore of the volute liner, and, after adjusting the distance from the top face of the volute liner discharge outlet to the top face of the front casing discharge outlet to 5 mm, tighten all the casing bolts.
(4) Adjust the clearance between the impeller and the throat bush to 0.75-1.00 mm, using the adjustment method described above.
6. Fitting the inlet and outlet pipe stub section
(1) At the inlet and outlet of the casing, fit 3 mm thick rubber gaskets respectively and tighten the bolts, and check whether the rubber gaskets are compressed. If a gasket is not compressed, a thicker gasket shall be used; the gap between the inlet/outlet flange and the casing inlet/outlet face shall be not less than 1 mm.
(2) An expansion joint is required to be installed before the inlet pipe stub, to facilitate removal.
(3) Turn the shaft by hand: before the packing is compressed, rotation shall be light, smooth and free from any tightness or sticking.
7. Assembly of the other parts
(1) Fit the coupling or the belt pulley.
(2) After the motor and the pump have been aligned, verify the rotation direction of the motor; only after it is confirmed correct, fit the coupling pins and pin rubber rings, or mount the belts.
(3) Fit the coupling guard or the belt pulley guard.
(4) Fit the packing in accordance with the packing filling requirements.
8. Trial run
During the trial run, pay attention to monitoring the pump for leakage, vibration, temperature rise, etc., and adjust the tightness of the packing promptly until it is appropriate.
VI. Wear Parts List
Table 4
