Goulds Pumps 3498 - IOM - Manual (Page 44)

TROUBLESHOOTING,
con't
3498 IOM 12/04
41
Problem Item Probable Cause Remedy
Not Enough
Pressure
24 Speed too low. See item 5.
25
Air leaks in suction piping or stuffing
box.
See item 11.
26 Mechanical defects. See item 18.
27 Vortex at suction inlet. See item 20.
28 Obstruction in liquid passages.
Check to see if suction and discharge valves are fully open. Dismantle
pump and inspect passages and casing. Remove obstruction.
29 Air or gases in liquid.
May be possible to over rate pump to a point where it will provide adequate
pressure despite condition. Better provide gas separation chamber on
suction line near pump and periodically exhaust accumulated gas.
See item 17.
Pump
Operates For
a Short Time,
Then Stops
30 Insufficient NPSHA. See item 17.
31 System head too high. See items 4 & 10.
Pump
Takes
Too Much
Power
32
Head lower than rating; thereby
pumping too much liquid.
Machine impeller’s O.D. to size advised by factory, or reduce speed.
33 Cavitation. See item 17.
34 Mechanical defects. See items 18, 19, 21, and 23.
35 Suction inlet not immersed. See item 20.
36
Liquid heavier (in either viscosity or
specific gravity) than allowed for. Use larger driver. Consult factory for recommended size.
Test liquid for viscosity and specific gravity.
37 Wrong direction of rotation. See item 6.
38 Stuffing box glands too tight.
Release gland pressure. Tighten reasonably. If sealing liquid does
not flow while pump operates, replace packing.
39
Casing distorted by excessive strains
from suction or discharge piping. Check alignment. Examine pump for rubbing between impeller and
casing. Replace damaged parts. Re-pipe pump.
40
Shaft bent due to damage — through
shipment, operation, or overhaul.
Check deflection of rotor by turning on bearing journals. Total
indicator run-out should not exceed .002" on shaft and .004"
on impeller wearing surface.
41
Mechanical failure of critical pump
parts. Check wear rings and impeller for damage. Any irregularity in these
parts will cause a drag on shaft.
42 Misalignment. Realign pump and driver.
43 Speed may be too high. Check voltage on motor. Check speed versus pump nameplate rating.
44 Electrical defects.
The voltage and frequency of the electrical current may be lower than
that for which motor was built, or there may be defects in motor. The
motor may not be ventilated properly do to a poor location.
45
Mechanical defects in turbine, engine
or other type of drive exclusive of
motor.
If trouble cannot be located consult factory.
5