Viking Pump TSM420: HL-LL 4925 - Manual

SECTION TSM 420
PAGE
1 Of 18
ISSUE E
INTRODUCTION
Installation, General Comments 1
Pump Installation 3
Preventative Maintenance 4
Safe Practices 5
Venting the Pump 5
Disassembly 7
Assembly 10
Thrust Bearing Adjustment 11
Installation of Carbon Graphite Bushings 12
Pressure Relief Valve Instructions 12
Troubleshooting 15
Ammonia 16
UNMOUNTED UNITS
MECH. SEAL
Units are designated by the
unmounted pump model numbers
followed by a letter(s) indicating
drive style
P = Commercial Speed Reducer
HL4925
K4925
KK4925
LQ4925
LL4925
fIgURE 1
Series 4925 Unmounted Pump
Model Chart Number
The illustrations in this manual are for identification purposes
only and cannot be used for ordering parts Obtain a parts
list from the factory or a Viking® representative Due to the
nature of the pump and the close manufacturing tolerances,
certain replacement parts are only available in assemblies
Always give complete name of part, part number or material
with model number and series number of pump when ordering
repair parts The pump or pump unit model number and serial
number are on the nameplate
In the Viking® model number system, the basic size letters
are combined with the series (4925) indicating either an
unmounted pump or mounted pump unit
This manual deals exclusively with Series 4925 Heavy Duty
Refrigeration Ammonia Pumps Refer to figures 1 thru 24
for general configuration and nomenclature used in this
manual NOTE: DO NOT OPERATE SERIES 4925 PUMPS
AT SPEEDS HIgHER THAN THOSE STATED IN CATALOg
SECTION 420 (Series 4925 Heavy Duty Refrigeration
Ammonia Pumps)
Consideration of the following points during design and
installation of the system will help insure successful operation
of the Viking Refrigeration Ammonia Pump
1. SUBMERGENCE - Submergence is the head of liquid
ammonia above the centerline of the pump suction port
A liquid head is necessary to keep the ammonia from
flashing as it goes into the pump The minimum liquid
head or submergence for good pump operation is 4 feet;
this is assuming a large, short suction line
2. SUCTION LINE - A large, short suction line is necessary
for good operation A good suction line:
2.1. is a suction line that is at least one size larger than
the pump suction port connection,
2.2. is connected to the pump by an eccentric reducer
(with the offset or eccentric portion down) when suction
to the pump is horizontal,
2.3. is as short as practical for the installation,
2.4. has no strainer (sometimes a temporary strainer is
used during start up to keep weld beads, etc , from going
through the pump),
2.5. uses a long sweep elbow if any elbow is
unnecessary,
2.6. has a full flow shut off valve,
2.7. and is fully insulated to prevent head pickup
3. INSULATION - Insulation on the suction line and on the
pump helps reduce the amount of heat pickup by the
heat pickup by the liquid ammonia
INSTALLATION,
gENERAL COMMENTS
NOTE: Single reservoir sight glass is standard Images are
shown with optional reservoir fittings
CONTENTS
Electronic copies of the most current TSM issue can be found on the Viking Pump website at www.vikingpump.com
VIKING PUMP, INC. • A Unit of IDEX Corporation •
Cedar Falls, IA 50613 USA
TECHNICAL SERVICE MANUAL
HEAVY-DUTY REfRIgERATION AMMONIA PUMPS
SERIES 4925
SIZES HL - LL