JABSCO Hy-Line, Installation, Operating, Maintenance And Spares Manual

Page: 10 / 52

2.07 PIPEWORK
Pipe runs and sizes should be established at
the time the pump is selected. When
installing pump do not deviate from this
design without rechecking pump selection:-
• Keep pipe runs short and pipe diameters
large; pipes may need to be larger
diameter than pump ports especially
when pumping viscous liquids.
• Inlet pipe must be as short as possible
and as large as possible to prevent
cavitation.
• Use large radius bends and full bore
valves. Avoids globe or needle valves on
viscous fluids.
• Fit isolation valves each side of the pump
to simplify maintenance.
• Fit vacuum/pressure gauges each side of
pump to monitor pressure conditions.
Once process is established (and will not
change), these can be removed.
• Avoid filters on the inlet side of pump if
possible. A clogged filter will cause
cavitation. A strainer - maximum hole size
50 microns - will help to protect pump
from damage by particles but must be
kept clear.
• Support pipework - do not allow weight of
pipe (and the fluid within) to be taken on
pump ports.
• Fit expansion joints if necessary to
prevent thermal expansion forces being
transmitted to pump.
• Ensure all pipe joints are adequately
sealed to be a) Air-tight under vacuum b)
Liquid tight under pressure and c) Steam
tight where applicable.
• Take special precautions when pumping
hazardous, hot, toxic or bacteriological
fluids - special joints (e.g. aseptic) and
high specification seals may be required.
• Use hot water/steam jackets or electrical
resistance tape to heat pipes carrying
liquids which thicken when cool. Provide
an interlock to prevent pump from running
unless liquid in pipes is at correct
temperature to avoid over pressure,
cavitation. or excessive drive shaft loads.
2.08 ENLARGED RECTANGULAR INLET
The weight of the hopper (and the product it
contains) must be supported separately and
not allowed to rest entirely on the pump as
this would affect the rotor clearances
leading to pump seizure. The mating flange
of a hopper or screw feeder should be
machined to the identical dimensions of the
rectangular inlet and sealed. This will avoid
ledges where product could ‘hang up’.
Ensure effective flow of viscous material into
the pump.
Page 8
Hy~Line
and
Ultima
Lobe Pumps
07/03