WORKING INSTRUCTION FOR
ALLEN GWYNNES 'NIMBUS' END SUCTION PUMP
SERIES : AGN
CONTENTS PAGE
COUPLING/PULLEYS ……….... 13
INSTALLATION…….. ……….... 13
PIPEWORK ………..………. 13
SUCTION PIPING …..………...………..………. 23
DELIVERY PIPING ….……….... 23
COUPLING ALIGNMENT .….……….... 24
OPERATION ………...….……….... 35
MAINTENANCE……….... 6
GLAND PACKING & MECHANICAL SEAL ……… 7
DISMANTLING……… 8
RE-ASSEMBLY ………...…..………. 9
RECOMMENDED SPARE PARTS ………. 10
THESE NOTES ARE PREPARED FOR GENERAL GUIDANCE ONLY AND DO NOT COVER ALL CIRCUMSTANCES. IF IN DOUBT PLEASE REFER TO OUR FACTORY.
COUPLING/PULLEYS
Ensure that the coupling/pulley bores are machined straight, smooth and concentric to the periphery and square to the face. The coupling should be drawn onto the pump shaft using the tapped hole on the shaft end or by a light tapping force only to prevent damage to the bearings. Apply oil to the shaft and coupling bore. To check concentricity of the
of the coupling, rotate it against a clock gauge. The total indicated reading should not be greater than 0.1mm.
It is advisable to disconnect the coupling when lifting the pump sets as distortion of base-plate may occur and if excessive will damage both the pump and motor bearings.
Check for coupling concentricity and squareness
INSTALLATION
Ensure that the baseplate is horizontal, grouted in and anchored by holding down bolts embedded in the foundation. The holding bolts should be evenly tightened only after the grouting has set. Check again that the baseplate is horizontal and level. (Baseplate must not be sagging or hogging.)
PIPEWORK
It is important that all pipework is supported independent of the pump and must not cause any strain on the pump casing. Flexible joints or bellows are recommend to isolate any possible vibration through the pipework with respect to the pump. Vibration transmitted through the pipework from other machinery can cause damage to bearings when the pump is not operating.
SUCTION PIPING
Suction pipework should be as simple as possible and must never be smaller than the suction branch of the pump. The flow velocity should not exceed 2m/s at rated flow rate.
A foot valve of equal or larger size than the suction pipe must be installed when the pump is operating under suction lift conditions. Make sure all joints are air tight and the pipework design must be such that no air pocket will form in any section. It is recommend that the pipe rises gradually towards the pump. All joint must be air tight.
When pumping under positive suction head,a foot valve is not required but a sluice or gate valve must be installed as near to the pump as possible.
DELIVERY PIPING
The pipework should be at least one size larger than the delivery branch to avoid excessive friction losses. To allow adjustment of pump discharge a gate/sluice valve must be fitted.
For installations having extensive pipework, a non-return valve with by pass must be fitted to protect the pump from water hammer.
To check the pump performance, pressure gauges should be fitted after the discharge and before the suction flanges.
In cases where pipework has high points and locks are likely to occur, ventcocks
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must be fitted.
COUPLING ALIGNMENT – Alignment must be checked and realigned if necessary prior to starting.
First disconnect the coupling halves by removing the coupling bolts and check that the periphery is concentric with the bore using a clock gauge. The eccentricity should not exceed 0.1mm. T.I.R. If higher readings are obtained the coupling halve should be replaced. Make sure that errors in alignment are within the coupling manufacturers’
limits. Coupling should be aligned with the bolts removed.
Presence of vibration during running can almost always be attributed to misalignment of coupling.
OPERATION:
1) Preparation for Starting
Before refitting the coupling bolt or pulley, belt, Check that the rotation of the motor is correct as indicated by the arrow on the pump casing. After refitting the coupling bolts rotate the shaft by hand to ensure that it rotates freely.
2) Priming
Fill up the pump casing and the suction pipe. Make sure that no air is trapped in the suction pipe and that and that the suction valve is fully open. Rotate a few revolutions to make sure no air is trapped in impeller.
3) Starting Up
Start the pump with the discharge valve closed to avoid overloading the motor. As soon as a steady pressure is built up, the valve must be opened slowly until the required flow rate is attained.At the same time, the discharge pressure gauge and the ammeter should be observed to make sure that the drop in the pressure is gradual and that the motor is not overloaded. If the pressure does not build up or is fluctuating excessively, it means that there is air in the pump or in the suction line.In such case,stop the pump, reprime and start again.
NEVER RUN A PUMP DRY FOR ANY LENGTH OF TIME.
If the valve is not yet fully open when the required flow rate has been attained,open the valve fully, see whether or not the motor will overload. If it overloads, it is recommended that the impeller diameter be reduced to give the duty at the fully open valve condition for following reasons:-
a) To avoid overloading of motor due to accidental opening of valve and b) To minimizes running cost.
4) Gland Packing - Running in
The gland packing is left only finger tight when the pump leaves the factory. A packed gland must leak and leakage should take place as soon as the stuffing box is pressurised. Until steady leakage takes place, the stuffing box may overheat. If this happens, the pump must be stopped and allowed to cool and when restarted, leakage should take place. If it does not,this operation should be repeated. Gland nuts should not be loosened. After the pump has been running for 10 minutes with steady leakage, tighten the gland nuts by one sixth of a full turn at 10 minutes interval until the leakage is acceptable, ensuring that over- heating does not occur.
5) Mechanically Sealed Pump
No attention is required unless the seal leaks which would indicate that the seal has been damaged or wrongly fitted.
ALWAYS ROTATE THE PUMP BY HAND FIRST BEFORE STARTING IF THE PUMP HAS BEEN LEFT IDLE FOR SOME TIME.
6) Overload Protection
Motor overload protection should be set at between 10-15% over the normal operating load (current) so that any system fault that may cause overloading will be detected before causing any serious damage to either the pump or the motor.
7) Changing over for stand-by operation
For installation with a stand-by pump, the change over should be done at regular interval so that both pumps are being equally used.
THE RUNNING UNIT MUST BE STOPPED COMPLETELY BEFORE STARTING UP THE
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OTHER UNIT TO AVOID SLAMMING OF THE NON-RETURN VALVE.
MAINTENANCE
Routine maintenance includes :- 1) Periodic re-lubrication of bearings.
2) Adjusting the gland packing.
3) Checking coupling alignment.
4) Checking tightness of nuts and bolts , etc.
1) Wipe lubrication nipples clean before fresh, clean grease is injected. Only a small amount of grease is required for each re-lubrication. Over greasing leads to hot running of bearings. Pump bearings are charged with Shell Alvania 3 grease at our factory.
BEARINGS MUST BE REGREASED BEFORE STARTING IF THE PUMP HAS BEEN STORED FOR A LONG PERIOD.
Pump Shaft Dia. 960 RPM 1450 RPM 1760 RPM 3000 RPM
24 - 20,000 14,000 7,000
32 2,000 1,400 1,200 600
42 1,800 1,200 900 500
65 1,400 800 - -
The interval should be reduced if the operating temperature is above 70'C or in high humidity condition.
ALTERNATIVE GREASE
Beacon -- Essco
Alvania 3 -- Shell
Mobilplex No.47 -- Mobil
Spheerol AP2 -- Castrol
Energrease LS2 -- Power/ B.P.
Regal AFBZ -- Regent/Caltex/Texaco
Bearing
The need to clean the bearings and their housing can only be determined by periodic inspection.
To clean and inspect the bearings, the pump should be dismantled and the bearings and housing cleaned as follows :-
a) Spray petroleum solvent (not paraffin) into the bearings and housing to remove all sludge and grease.
b) Spray the bearings with light lubrication oil to remove solvent and protect them for moisture and dust.
Inspect the bearings for any sign of damage or impending failure. If in doubt, the bearings should be replaced.
Repacked the bearing housing with the recommended grease to not more than one half of the volume.
Ensure that grease is well packed between rollers. Do not over fill as this will lead to overheating.
LUBRICATION INTERVAL IN HOURS OF OPERATION
Gland Packing
The frequency of replacing packing depends entirely on the type and condition of fluid being pumped.
Packing must not be over compressed, otherwise the sleeve will wear rapidly causing overheating in the stuffing box and may overload the motor.
When repacking the stuffing box,all rings must be replaced. Cut joint of adjacent rings should be placed at 120 degrees apart. New packing must be "run in" as described under Starting Up.
If the sleeve is badly scored, replace the sleeve. The stuffing box must be cleaned before inserting new packing.
Packing Size
Pump Shaft Dia. Packing Size No. of rings Sleeve dia.
24 mm 8 mm 4 20 or 28 mm
32 mm 6 mm 4 52 mm
42 mm 8 mm 4 61 mm
65 mm 10 mm 4 84 mm
The type of packing used will depend on the liquid being pumoed therebefore, the same type of packing should be used for replacement.
Ring Cutting
1) Place the packing round the shaft or round a mandrel of the specified dimater.
2) To assist in cutting rings, two guid lines parallel to the shaft axis and separated by a distance equal to the packing section may be drawn on the spiral.
3) Cut the rings from the spiral at an angel of 45 degrees diagonal across the guide lines no gap is left between the ends.
3) It is advisable to check the coupling alignment before restarting, if the pump has been left idle for a considerable length of time.
4) Check that all bolts and nuts securing the pump sets and pipework are not lose before starting if the pumps has been left idle for long time before restarting.
Mechanical Seal
No attention is required during the normal working life of a mechanical seal. When a seal starts leak, a replacement is required. Again the type of seal fitted will depends on the type of liquid handled. The same type of seal should be used for replacement and the manufacturer’s fittingPage 7 of 11
instruction should be followed closely.
DISMANTLING - a) For 32mm,42mm and 65mm shaft end pumps.
b) For 24mm shaft end pumps only.
1) Isolate the power supply and make sure that it cannot be switched on accidentally.
2) Close suction and discharge valves (if installed).
3) Drain pump casing by removing the drain pug.
4) Remove coupling guard and disconnect coupling. If a spacer coupling is used, neither the pipework not the motor need to be moved,otherwise, move whichever one is more convenient.
5a)Remove the screws securing the backcover to the casing and using the tapped holes on the backcover, the pump assembly can be jacked out from the casing. Make sure the 'O' Rinf is not damaged.
5b) Remove the nuts securing the backcover to the casing and then the rotating assembly can be pulled away from casing. Asbestor gasket is used for sealing between the backcover and the casing.
6) Remove the impeller screw and washer, then withdraw the impeller and key.
7) Remove the mechanical seal assembly if fitted. (For mechanical sealed pump only)
8) Loosen the grub screw on the coupling half and withdraw the half coupling from the shaft.
9)Remove the cap screws securing the bearing bracket to the backcover.
10a) Loosen the gland nuts to relieve the packing and withdraw the bearing bracket from the backcover.
The shaft sleeve will remain on the shaft and the packing, lantern ring and gland will be left in the backcover. (For packed gland pump only)
10b) No shaft sleeve is fitted.
11) Remover the four screws on each end of the bracket and remove the bearing cover. The brass shims should be removed and retained safely for re-assembly.
12a) Press the shaft from one end and then from the other to remove the bearing outer race from the bearing bracket. Remove the bearings from the shaft as required.
RE-ASSEMBLY
To re-assemble the pump, reverse the dismantling procedure observing the following instruction:- 1) Clean the flanges and register faces ensure that they are free from any rough edges and burrs. Clean the bearing bracket thoroughly.
2) If old bearingd are to be re-fitted, they should be thoroughly cleaned and greased properly.(see under Maintenance). Bearings should be mounted onto the shaft by pressing the inner cone or by heating it up in an oil bath to a temperature of 80-90ºC. above ambient but not higher than 120ºC. The bearings must not be in direct contact with thw container to avoid local heating. A bearing should never be heated using a flame.
3a) (i) Press ther bearing cup into the impeller end of the bracket.
(ii) Fill the bearing end cover with clean grease and then fit onto the bracket. Ensure that the slot matches up with the grease nipple.
(iii) Put the shaft/bearing assembly through the coupling end repeat (i) and (ii). Make sure the shims are fitted. Tighten all the screws.
(iv) Mount a clock gauge at the shaft end, and press hard the shaft to one end and then to the other to check the bearing axial clearance. The clearance should be as stated on the nameplate. Repeat a few times by rotating the shaft until a consistant reading is obtained. Ass or remove shims as necessary.
3b) (i) The end float has been pre-set in the ball bearing and no settling is required but make sure that the shaft rotates freely after tightening the screws on the end cover.
(ii) Pack the bearings with grease before pressing the shaft/bearing assembly into the bracket.
4a) Fit the gland sleeve to the shaft and slide the lantern ring over the sleeve before fitting the bearing bracket to the backcover.
4b) Press the lantern ring in to the backcover stuffing box first before fitting the bearing bracket to the back cover.
When fitting a mechanical seal, the seal should fitted into the backcover before fitting the bearing bracket to the backcover. Absolute care must be taken to ensure that the seal surface is not scratched, The seal manufacturer's instruction must be followed closely.
5) After the impeller is fitted, the cap screw must be tightened properly.
6a) Make sure that the 'O'Ring is fitted properly between the casing and cover and if it is cut or badly worn, it should be replaced.
7) The pump half coupling should be drawn on utlising the tapped hole in the shaft end.
8) The cap screw holding the backcover to the casing should be tightened alternatively and evenly.
9) Check the coupling alignment and the motor rotation (If the cables were disconnected) before fitting
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the coupling bolts.
Recommended Spare Parts
One impeller One set bearings One shaft
One set mechanical seal or soft packed assembly consisting of sleeve , gland , packing and lantern ring.
WHEN ORDERING SPARE PARTS ALWAYS QUOTE THE SERIAL NUMBER OF THE PUMP TO ENSURE THAT YOU GET THE CORRECT PARTS.
Technical Data
Coupling bore details (Refer to catalogue)
A grub screw must be screwed through each coupling hub onto the key.
Bearing End Float
Socket Head Cap Screws
M 20
TighteningTorque 7 kgf.m (50.6 lbf. ft) 167 kgf.m (115.6 lbf. ft)
29 kgf.m (210 lbf. ft) M 12
M 16 Screw Size
42 + 0.025
42 mm 50 mm 0.11 - 0.15 mm
65 mm 70 mm 0.11 - 0.15 mm
Shaft End Bearing End-Float
32 mm 41 mm 0.11 - 0.15 mm
65 + 0.030
GG FF
27.3 + 0.2 35.3 + 0.2 45.3 + 0.2 69.4 + 0.2
8 ± 0.018
12 ± 0.0215 18 ± 0.0215 24 + 0.021
32 + 0.025 10 ± 0.018
D (H7)
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