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7

 

L - LOCATING TROUBLE

1. No Liquid Delivered

a. Wrong direction of rotation
b. Speed too low - Check with revolution counter
c. Discharge head is too high
d. Impeller or pipe lines plugged
e. Pump not primed
f.  Suction lift too high, over 15 feet (check with
 vacuum 

gauge)

2. Not Enough Liquid Delivered

a. Discharge head higher than anticipated
b. Speed too low (check with revolution couter)
c. Air leaks in suction pipe or stuffi ng box.
d. Suction lift too high, over 15 feet (check with
 vacuum 

gauge)

e. Impeller partially plugged
f.  Not enough suction head for hot water
g. Mechanical defects
  1. Impeller worn or damaged
  2. Casing worn
h. Foot valve too small
i.  Foot valve not immersed deep enough
k. Wrong direction rotation

3. Not Enough Pressure

 

a. Air in water

 

b. Mechanical defects

 

c. Impeller diameter too small

 

d. Speed too low

4. Pump Works for a while, then Quits

 

a. Leaky suction line

 b. 

Suction 

plugged

 

c. Suction lift too high, over 15 feet (check with  

  vacuum 

gauge)

 

d. Air or gas in liquid

5. Pump Takes Too Much Power

 

a. Speed too high

 

b. Liquid either viscous or heavier than water, or 

  both.
 

c. Strain on casing caused by piping misalignment

 

d. Head lower than rating

 e. 

Mechanical 

defects

 

  1. Shaft bent

 

  2. Impeller binds in casing

  3. 

Stuffi ng box packing too tightly adjusted

When ordering repairs, refer to drawing and give 
information stamped on nameplate which is:
Figure Number, Pump Size and Serial Number. Unless 
we have this information, we cannot identify pump and 
guarantee the repairs to fi t.

Summary of Contents for DEMING 3906 Series

Page 1: ...ms reserves the right to change product without prior written notification 420 Third Street 83 West Drive Bramton Piqua Ohio 45356 Ontario Canada L6T 2J6 Phone 937 778 8947 Phone 905 457 6223 Fax 937 773 7157 Fax 905 457 2650 www cranepumps com Form No 119998 Rev B Series 3906 DEMING DEMING INSTALLATION OPERATION MAINTENANCE MANUAL End suction Centrifugal Pumps DISCONTINUED Parts may NOT be availa...

Page 2: ...nd discharge openings DO NOT insert fingers in pump with power connected Always wear eye protection when working on pumps Make sure lifting handles are securely fastened each time before lifting DO NOT operate pump without safety devices in place Always replace safety devices that have been removed during service or repair Secure the pump in its operating position so it can not tip over fall or sl...

Page 3: ...YOU BEGIN Motor driven pumps are carefully aligned on sub base before shipment However after they are placed upon the foundation and sub base is bolted down the alignment must be rechecked and in MOST CASES it will be found necessary to carefully realign the unit Quite often a noisy pump is due to pump and motor not being properly aligned IN SUCH CASES WE DISCLAIM ALL RESPONSIBILITY FOR PROPER WOR...

Page 4: ...s very important that the suction and discharge pipes line up naturally with the pump DO NOT pull pipes into position with flange bolts Support pipes independently of the pump to eliminate all strain on the pump casing Select discharge pipe size so velocity is under 8 feet per second Avoid sharp changes in pipe sizes 7 After pipes have been connected to pump check alignment at drive coupling Corre...

Page 5: ...s and remove the four cap screws holding pump to sub base Drain pump by removing drain plug 4 in the bottom of the pump casing 1 CLEAN AND INSPECT ALL PARTS Extreme care should be exercised in keeping the parts clean Special precautions should be taken to keep ball bearings dirt free while in or out of the pump The dirt will damage the ball bearings thus shortenting the trouble free service life o...

Page 6: ...5 Brace support head 11 and tap lightly on end of shaft 2 Shaft and impeller can now be removed as a unit Slinger 6 seal gland 32 seal gland gasket 29 seal 31 and spacer sleeve 35 may now be removed from the support head 11 6 To remove bearings 24 and 26 remove screws 15 and bearing cover 14 By pulling on bearing collar 13 bearing 24 can be removed Insert a bar into the coupling end of the support...

Page 7: ...mall i Foot valve not immersed deep enough k Wrong direction rotation 3 Not Enough Pressure a Air in water b Mechanical defects c Impeller diameter too small d Speed too low 4 Pump Works for a while then Quits a Leaky suction line b Suction plugged c Suction lift too high over 15 feet check with vacuum gauge d Air or gas in liquid 5 Pump Takes Too Much Power a Speed too high b Liquid either viscou...

Page 8: ...rease Fitting 13 THrust Bearing Collar 14 Bearing Cover 15 Self Tapping Screws 16 Shake Proof Washers 17 Hex Nuts 18 Name Plate 19 Drive Screws 20 Bearing Order ITEM No DESCRIPTION 21 Dust Plug 22 Hex Nuts 23 Drip Pan with Stuffing Box only 24 Ball Bearings 25 Set SCrews 26 Ball Bearings 27 Pipe Plug 28 Packing Seat Washer 29 Seal Gland Gasket 31 Seal 32 Seal Gland 35 Spacer Sleeve 36 Pipe Plug 37...

Page 9: ... conducted by or for user and laboratory tests corrected for field performance the latter shall control RECOMMENDATIONS FOR SPECIAL APPLICATIONS OR THOSE RESULTING FROM SYSTEMS ANALYSES AND EVALUATIONS WE CONDUCT WILL BE BASED ON OUR BEST AVAILABLE EXPERIENCE AND PUBLISHED INDUSTRY INFORMATION SUCH RECOMMENDATIONS DO NOT CONSTITUTE A WARRANTY OF SATISFACTORY PERFORMANCE AND NO SUCH WARRANTY IS GIV...

Page 10: ...CRANE PUMPS SYSTEMS INC 420 THIRD STREET PIQUA OHIO 45356 U S A ...

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