2
STRUCTURAL LIMITS
Operating conditions, such as speed, fluid viscosity, inlet pressure, temperature, filtration, duty cycle,
mounting, drive type, are interrelated. Due to variable conditions, specific application limitations may vary
from structural limitations. This equipment must not be operated without verification that operating
requirements are within published capabilities as shown in the appropriate pump brochures (available from
local Imo Pump offices and representatives listed in Manual CA-1).
Under no circumstances are the following structural design limits to be exceeded.
Discharge Pressure............................................................2000 PSIG Standard Pump
Inlet Pressure .........................................................................55 PSIG Standard Pump
(Modification to some basic design pumps allows continuous inlet pressures up
to 400 PSIG, consult Imo Pump for higher or intermittent pressures.)
Speed Limits ................................................................................2300 RPM Maximum
(Consult Imo Pump for Minimum Speed)
Viscosity ........................................................................60 SSU Minimum Book Rating
(Consult Imo Pump for minimum viscosity with relation to specific speed and
pressure.)
Temperature...............................................................250 degrees F (Standard Pump)
Drive............................................................................................................. Direct only
Mounting ................................................................................................. Foot mounted
DESCRIPTION of PUMP FEATURES
WARNING
The GLH series pump parts are not interchangeable with previous designs.
Modification kits containing GLH design parts are specified in addition to major
repair kits for all 8L series pumps currently in service.
Balance
By design, all rotor sets are hydraulically balanced in the radial direction. Idler rotors (40 and 41) are balanced
axially by internally transferring high pressure oil from the pump discharge end to the pump inlet end (thrust
end). The high pressure oil is transferred to the pump inlet end through bores that have been gun drilled
axially through the rotor housings (3 and 5).
In order to provide axial hydraulic balance on the power rotor (22), a balance piston (24) is provided. The sizes
of the balance piston (24) and the balance piston bushing (15) in which it rotates are selected to produce
minimum axial thrust loads on the anti-friction ball bearing (31) under the conditions of operation that are
"normal" for the application.
WARNING
When a unit is purchased, if no inlet conditions are specified, the power rotor will be
provided with standard balance. If a unit with standard balance is installed on an
operation with high inlet pressure, both the ball bearing (31) and the mechanical seal
(27) may be overloaded. If the unit has been fitted to operate with high inlet
pressure, operation on low inlet pressure can overload the ball bearings. Do not
change inlet pressure radically without approval from Imo Pump Division.
Summary of Contents for GLH8L-462 Series
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