6
and coat with light oil.
4. Oil new seat rubber (3) with light oil and position ceramic
seat (2) in rubber fi rmly and squarely.
5. Push seat assembly (2) and (3) into position in the
frame (19) using a close fi tting sleeve with end
square with bore. Protect the ceramic seat face (2) from
damage by placing a paper ring between the sleeve and
seat.
DO NOT
hammer the seat as it is easily broken.
Be sure to remove the paper after installing the seat.
6. See Step 2 under “Reassembly”.
7. Oil shaft (6) and inside of the seal assembly (4) and
slide seal (4) onto the shaft (6).
8. Procede with Steps 4 and 5 under “Reassembly”.
J - 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.
Mechanical Seal for Fig. 3904
Mechanical Seal for Fig. 3914
Summary of Contents for Deming 3904 Series
Page 10: ...Notes ...
