Problems: Causes And Remedies; Appendix; Permissible Pump Pressure - Andritz HP 45 Série Instructions De Service

Series HP 45

6. Problems: Causes and Remedies

1) Output low or no output at all
2) Excessive output
3) Motor overload and thermistor stops
4) Water hammer in the system
5) Repeated mechanic damages after short period
1) 2) 3) 4) 5) Problem
Excessive draw-down in sump, excessive
suction lift or inadequate flooded suction
Pump not completely primed
Air lock in suction pipe
Excessive delivery pressure
Insufficient delivery pressure
Wrong rotation
Pipework, fittings or pump clogged
Pump internal worn
Speed too low
Speed too high
Motor two phasing
Set misaligned
Packed gland packing overtightened
Excessive density of pumped medium
System design
System default

7. Appendix

7.1

Permissible pump pressure

Sealing
gland packing
mechanical seal unbalanced (cast chrome/carbon)
mechanical seal unbalanced (silicon carbide/
silicon carbide)
mechanical seal balanced (silicon carbide/carbon)
mechanical seal balanced (silicon carbide/silicon
carbide)
* The maximum permitted final pump pressure [bar] consists of the intake pressure and the pump delivery head at zero capacity.
Remedy
• Check the system design and pipe sizing
• Check the settings and operation of level controls
• Vent the pump
• Check shaft sealing arrangements for air tightness
• Prime the suction pipe
• Check suction pipework and valves for air tightness
• Open up restricting valves
• Check system design for excessive pressure losses
• Modify pump (after consulting the manufacturer)
• Check the system design
• Restrict discharge valve
• Correct rotation
• Remove deposits or obstructions
• Replace worn parts
• Check electrical installation
• Check electrical installation
• Check electrical installation
• Check alignment
• Eliminate loads from pipework and realign set
• Slacken gland packing
• Fit a more powerful motor (after consulting the manufacturer)
• Examine system design, remedy the cause
• Fault diagnosis after inspection
Maximum admissible final pump pressure*
Max. temperature
EN-GJL-250
-20°C up to +110°C
-20°C up to +120°C
-20°C up to +80°C
-20°C up to +140°C
-20°C up to +80°C
Table 4: Problems
[bar]
casing parts made of
CuSn10-C
40 35
12 12
12 12
40 35
40 35
Table 5: final pressure of pump
1.4408
40
12
12
40
40
23