106-A00 Page 16/20
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 casing: File and clean when
necessary.
MLX Models - From the tell-tale hole in the hub, or where
the hub meets the head.
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
Damaged hub O-rings: Inspect and replace if necessary.
MLN Models - From the seal housing or around the shaft. Damaged Mechanical Seal: See Above.
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.
MLN Models - From the stuffing box in the hub.
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.
ESCAPING GREASE
Location
Probable Cause/Corrective Action
MLX Models - Around the pump shaft.
Damaged grease seal: Remove the bearing cover and inspect the
grease seal for damage. Replace if necessary.
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.
MLX Models - Improper locknut adjustment.
Locknuts must be adjusted properly to center the rotor and shaft
between the heads. Refer to "Locknut Installation" on Page 10.
MLN Models - Excessively tight packing.
Refer to "Packing Adjustment" on Page 15.
MLX & MLN Models - 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.
MLX & MLN Models - Mechanical seal drive tangs not
engaged.
The driving tangs of the seal jacket must be engaged in the slots in the
rotor (MLX Models), or in the keyways of the shaft threads (MLN
Models).
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:
The relief valve must be
adjusted such that the pump will not bypass during normal operation.
WARNING: Internal bypassing of liquid elevates the liquid
temperature. Use the internal bypass valve for brief periods only
and at differential pressures below 125 psi (8.6 bar). For extended
periods of higher pressures, the internal bypass port must be
plugged and the liquid returned back to the source.
MLN Models - Stuffing box of hub.
Packing: NEVER tighten packing without checking afterward for
overheating. If packing is old or worn, it will overheat – replace with a
new packing set.
OTHER POSSIBLE CAUSES OF OVERHEATING:
• Improper relief valve adjustment
(See "Relief Valve" on Page 6).
• Plugged discharge line.
• Closed valve.
Содержание PSG BLACKMER MLN4B
Страница 19: ...106 A00 Page 19 20 NOTES ...