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TROUBLESHOOTING
NOTICE:
Maintenance shall be performed by qualified technicians only,
following the appropriate procedures and warnings as presented in this manual.
LEAKAGE
Location
Probable Cause/Corrective Action
Between the head & casing
Damaged head O-ring: Inspect and replace if necessary.
Burrs/dirt in head O-ring groove or cylinder: File and clean as
necessary.
Around the shaft
Packing: Adjust the packing. If this does not solve the problem, replace
the packing with a complete new set.
NOTE: On pumps equipped with packing, some leakage is necessary,
and in some cases is desirable, depending on the application.
Damaged shaft surface: Check the surface of the shaft in the seal area
for damage. File any small burrs or ridges. If damage is severe, replace
rotor & shaft.
New Mechanical Seals: New seals may leak slightly at start up, but
should seal up shortly thereafter.
Damaged mechanical seals: Check for damaged O-rings or cracked,
scratched or worn seal faces
SHAFT BINDING
Probable Cause
Corrective Action
Burrs, dirt or foreign particles on the heads or discs.
During assembly, both heads and discs must be clean and smooth. File
any burrs or rough spots, and wipe the discs with a clean cloth and
alcohol to remove any dirt or foreign particles.
Excessively tight packing.
Refer to "Packing Adjustment".
Contaminated mechanical seal faces.
Any trace of grease or dirt on the seal faces will prevent the faces from
mating properly, causing the rotor and shaft to bind or turn hard. Use a
tissue paper & alcohol to clean the seal faces. NOTE: Apply a light oil
or suitable lubricant to bronze seal faces only.
Other possible causes of shaft binding --------------------------------------------------------------------------------------------------
• Foreign particles on rotor, liner or vanes.
• Damaged vanes or rotor.
• Bent push rods.
• Liquids that "set up" when inactive.
OVERHEATING
Location
Probable Cause/Corrective Action
Pump equipped with internal relief valve.
Continual, full bypassing of the liquid:
Properly adjust the relief
valve so that the pump will not bypass during normal operation.
WARNING: Internal bypassing of liquid elevates the liquid
temperature. Only use the internal bypass valve for brief periods
and at differential pressures below 125 psi.
For extended periods of higher pressures, the internal bypass
port must be plugged and the liquid returned back to the source.
Pumps with packing.
Packing: NEVER tighten the packing without checking afterward for
overheating. If packing is old or worn, it will overheat and should be
replaced.
Other possible causes of overheating ----------------------------------------------------------------------------------------------------
• Improper relief valve adjustment
(See "Relief Valve").
• Plugged discharge line.
• Closed valve.
LOW DELIVERY RATE
Probable Cause
Corrective Action
Relief valve setting too low, causing the liquid to bypass. Set the relief valve 20 psi (1.4 bar) higher than the differential pressure.
Other possible causes of a low delivery rate ------------------------------------------------------------------------------------------
•
Restriction in the suction line.
•
Resistance in the discharge line.
•
Air leaks in the suction line.
•
Damaged or worn pump parts.
•
Pump speed too low or too high.
•
Relief valve leaking.
•
Relief valve sticking open, or not properly seating.
•
Dirty
strainer.
Содержание SNP1.25
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