Viking 823 User Manual

TECHNICAL SERVICE MANUAL

MAGNETIC DRIVE PUMPS

SERIES 823 - STEEL

825 - CAST IRON

827 - STAINLESS STEEL

SIZES LQ, LS, Q & QS

SECTION TSM 845.1

PAGE 1 OF 13

ISSUE C

CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . 1

Special Information . . . . . . . . . . . . . . . . . . . 3

Pressure Relief Valves . . . . . . . . . . . . . . . . . 3

Maintenance . . . . . . . . . . . . . . . . . . . . . . 3

Disassembly: Pump. . . . . . . . . . . . . . . . . . . 6

Pump Rotation . . . . . . . . . . . . . . . . . . . . . 7

Port Arrangement . . . . . . . . . . . . . . . . . . . . 7

Disassembly: MD-D Series Coupling . . . . . . . . . . 7

Bearing Housing . . . . . . . . . . . . . . . . . . . . 9

Disassembly of Bearing Housing

Assembly of Bearing Housing . . . . . . . . . . . .

Installation of Bushings . . . . . . . . . . . . . . . . . 9

Pump Assembly. . . . . . . . . . . . . . . . . . . . .10

Adjusting Head Gasket End Clearance . . . . . . . . 11

Assembly: D Series Coupling . . . . . . . . . . . . . 11

Troubleshooting. . . . . . . . . . . . . . . . . . . . 12

Pressure Relief Valves . . . . . . . . . . . . . . . . 12

Pressure Adjustment

Disassembly: Relief Valve. . . . . . . . . . . . .

Assembly: Relief Valve

. . . . . . . . . . . . . . . 12

. . . . . . . . . . . . . . 13

WARNING !

Persons with surgical implants of a
metallic or electronic nature should
avoid working on pump – especially the
inner magnet assembly.

. . . . . . . . . . 9

INTRODUCTION

The illustrations used in this manual are for identification
purposes only and should not be used for ordering parts.
Secure a parts list from the factory or a Viking® representative.
Always give the complete name of the part, model and serial
number of the pump when ordering repair parts. The pump
model and serial number can be found on the nameplate
secured to the pump.

In the Viking model number system, the basic size letters are
combined with series number (825, 823, or 827) indicating
basic pump construction material (cast iron, steel or stainless

9

steel).

MODEL NUMBER CHART

UNMOUNTED PUMP UNITS

LQ-825, 823, 827

13

LS-825, 823, 827

Q-825, 823, 827

QS-825, 823, 827

This manual deals only with Series 825, 823 and 827 magnetic
drive pumps and couplings. Refer to Figures 1 through
21 for general configurations and nomenclature used in this
manual. Pump specifications and recommendations are listed
in Catalog Section 845.

Units are designated by the un­mounted pump model numbers
followed by the magnetic coupling
size and a letter indicating drive style:

B – Bracket Mount
R – Viking Reducer Drive
P = Commercial Reducer Drive
(Example: LS-827 MD-D140 R)

FIGURE 1

LS-825 MD-D290 R

Complete Unit on Base with Viking “C” Reducer

VIKING PUMP, INC. • A Unit of IDEX Corporation • Cedar Falls, IA 50613 USA

FIGURE 2

QS-825 MD-D450 B

Bearing Carrier, Footed Pump and Coupling Bracket

Jacketed Pump Bracket

SAFETY INFORMATION AND INSTRUCTIONS

IMPROPER INSTALLATION, OPERATION OR MAINTENANCE OF PUMP MAY CAUSE SERIOUS INJURY
OR DEATH AND/OR RESULT IN DAMAGE TO PUMP AND/OR OTHER EQUIPMENT. VIKING’S WARRANTY
DOES NOT COVER FAILURE DUE TO IMPROPER INSTALLATION, OPERATION OR MAINTENANCE.

THIS INFORMATION MUST BE FULLY READ BEFORE BEGINNING INSTALLATION, OPERATION OR
MAINTENANCE OF PUMP AND MUST BE KEPT WITH PUMP. PUMP MUST BE INSTALLED, OPERATED
AND MAINTAINED ONLY BY SUITABLY TRAINED AND QUALIFIED PERSONS.

THE FOLLOWING SAFETY INSTRUCTIONS MUST BE FOLLOWED AND ADHERED TO AT ALL TIMES.

Symbol
Legend :

!

!

!

!

!

WARNING

!

WARNING

Danger - Failure to follow the indicated

instruction may result in serious injury

!

or death.

BEFORE opening any liquid chamber (pumping
chamber, reservoir, relief valve adjusting cap fitting,
etc.) be sure that :

● Any pressure in the chamber has been completely
vented through the suction or discharge lines or
other appropriate openings or connections.

● The pump drive system means (motor, turbine,
engine, etc.) has been “locked out” or otherwise
been made non-operational so that it cannot be
started while work is being done on the pump.

● You know what material the pump has been
handling, have obtained a material safety data
sheet (MSDS) for the material, and understand
and follow all precautions appropriate for the safe
handling of the material.

BEFORE

are in place.

DO NOT operate pump if the suction or discharge
piping is not connected.

DO NOT place fingers into the pumping chamber or
its connection ports or into any part of the drive train
if there is any possibility of the pump shafts being
rotated.

DO NOT exceed the pumps rated pressure, speed, and
temperature, or change the system/duty parameters
from those the pump was originally supplied, without
confirming its suitability for the new service.

BEFORE

● It is clean and free from debris

● all valves in the suction and discharge pipelines

are fully opened.

● All piping connected to the pump is fully supported

and correctly aligned with the pump.

● Pump rotation is correct for the desired direction

of flow.

operating the pump, be sure all drive guards

operating the pump, be sure that:

WARNING

WARNING

!

WARNING

!

!

!

WARNING

!

WARNING

Warning - In addition to possible serious

injury or death, failure to follow the
indicated instruction may cause damage
to pump and/or other equipment.

INSTALL pressure gauges/sensors next to the
pump suction and discharge connections to monitor
pressures.

USE extreme caution when lifting the pump. Suitable
lifting devices should be used when appropriate. Lifting
eyes installed on the pump must be used only to lift
the pump, not the pump with drive and/or base plate.
If the pump is mounted on a base plate, the base plate
must be used for all lifting purposes. If slings are used
for lifting, they must be safely and securely attached.
For weight of the pump alone (which does not include
the drive and/or base plate) refer to the Viking Pump
product catalog.

DO NOT attempt to dismantle a pressure relief valve
that has not had the spring pressure relieved or is
mounted on a pump that is operating.

AVOID contact with hot areas of the pump and/or
drive. Certain operating conditions, temperature
control devices (jackets, heat-tracing, etc.), improper
installation, improper operation, and improper
maintenance can all cause high temperatures on the
pump and/or drive.

THE PUMP must be provided with pressure protection.
This may be provided through a relief valve mounted
directly on the pump, an in-line pressure relief valve,
a torque limiting device, or a rupture disk. If pump
rotation may be reversed during operation, pressure
protection must be provided on both sides of pump.
Relief valve adjusting screw caps must always point
towards suction side of the pump. If pump rotation is
reversed, position of the relief valve must be changed.
Pressure relief valves cannot be used to control pump
flow or regulate discharge pressure. For additional
information, refer to Viking Pump’s Technical Service
Manual TSM 000 and Engineering Service Bulletin
ESB-31.

THE PUMP must be installed in a matter that allows
safe access for routine maintenance and for inspection
during operation to check for leakage and monitor
pump operation.

SECTION TSM 845.1 ISSUE C PAGE 2 OF 13

SPECIAL INFORMATION

DANGER !

Before opening any Viking pump liquid
chamber (pumping chamber, reservoir,
relief valve adjusting cap fitting etc.)
Be sure:

1. That any pressure in the chamber has
been completely vented through the
suction or discharge lines or other
appropriate openings or connections.

2. That the driving means (motor,
turbine, engine, etc.) has been “locked
out” or made non-operational so that
it cannot be started while work is
being done on pump.

3. That you know what liquid the
pump has been handling and the
precautions necessary to safely
handle the liquid. Obtain a material
safety data sheet (MSDS) for the
liquid to be sure these precautions
are understood.

Failure to follow above listed
precautionary measures may result in
serious injury or death.

DISCHARGE

SUCTION

RELIEF VALVE ADJUSTING SCREW CAP

FIGURE 3

For additional information on pressure relief valves, refer
to Technical Service Manual TSM000 and Engineering
Service Bulletin ESB-31.

MAINTENANCE

ROTATION: Viking Mag Drive® pumps are directional.
Shaft rotation determines which port is suction and which is
discharge. The port located where pumping elements (gear
teeth) come out of mesh is the suction port. Do not attempt
to operate the pump in the opposite direction. See PUMP

ROTATION on page 7.

PRESSURE RELIEF VALVES:

1. Viking pumps are positive displacement pumps and must

be provided with some sort of pressure protection. This
may be a relief valve mounted directly on the pump, an
inline pressure relief valve, a torque limiting device or a
rupture disk. Do not rely on decoupling of magnets for
protection from over pressure; this may result in damage
to the magnets, pump, or other equipment.

2. If pump rotation is to be reversed during operation,
pressure protection must be provided on both sides of
the pump.

3. The relief valve adjusting screw cap must always point
towards the suction side of the pump. Refer to Figure 3. If
the pump rotation is reversed, remove the pressure relief
valve and turn end for end (see PUMP ROTATION on
page 7 first for additional steps required for proper
operation.)

CAUTION !

Rare earth magnets used in these
couplings have extremely strong
magnetic fields capable of changing the
performance or damaging items such as
the following:

Pacemakers
Metal Implants
Watches
Computers & discs
Credit Cards

Completely assembled magnetic
couplings will not affect items listed
above.

Altered performance or damage can
occur only when the coupling halves are
separated.

There are no known harmful effects of
these magnetic fields on the human
body.

4. Pressure relief valves cannot be used to control pump

flow or regulate discharge pressure.

SECTION TSM 845.1 ISSUE C PAGE 3 OF 13

TEMPERATURE

MONITOR

(OPTIONAL)

BRACKET
BUSHINGS

BALANCE
PLATE

CASING

HEAD
GASKETS

OUTER

MAGNET

ASSEMBLY

BEARING
CARRIER

ASSEMBLY

COUPLING

BRACKET

CANISTER

INNER MAGNET
ASSEMBLY

FIGURE 4

CUTAWAY VIEW MAG DRIVE PUMP, MODEL LS-825 MD-D B ILLUSTRATED

Series 825, 823, 827 pumps are designed for long, trouble-free
service life under a wide variety of application conditions with
a minimum of maintenance. The points listed below will help
provide long service life.

CLEANING UNIT: Keep the pump, coupling and motor as
clean as possible. This will facilitate inspection, adjustment,
and repair work.

STORAGE: If the pump or coupling are to be stored, drain
the pump and pour non-detergent SAE 30 weight oil into the
pump port. Apply grease to the pump or the coupling shaft
extension, if present or accessible. Viking suggests rotating the
pump shaft every 30 days to circulate the oil in the pump. The
coupling should be stored in a dry area. Note: if the liquid to

be pumped reacts with oil, use an acceptable alternate.

CANISTER
O-RING

PUMP

BRACKET

ROTOR

IDLER

4. Snap ring pliers (heavy duty)

EXTERNAL 2-810-029-375

5. Bearing locknut spanner wrench
(Source: #471 J.H. Williams & Co. or equal)

6. Arbor press

7. Feeler gauge set

8. Bearing housing jack screws (2 required)

(Supplied with coupling 2-297-022-999)

9. Brass bar

DANGER !

HEAD

IDLER
PIN

PRESSURE
RELIEF
VALVE

SUGGESTED REPAIR TOOLS: The following tools are

required to properly repair a Mag Drive pump. These tools
are in addition to standard mechanics tools such as open end
wrenches, socket set, pliers, screw drivers, etc. Most items can
be obtained from an industrial supply house.

1. Soft headed hammer

2. Allen wrenches

3. Spanner wrench, adjustable pin type for use on end cap

(Source: #482 J.H. Williams & Co. or equal)

SECTION TSM 845.1 ISSUE C PAGE 4 OF 13

Follow recommended procedures to
assemble or disassemble magnetic
couplings.

Failure to do so may result in serious
injury.

FIGURE 5

EXPLODED VIEW – LQ & LS SIZE MAG DRIVE PUMPS

ITEM DESCRIPTION ITEM DESCRIPTION ITEM DESCRIPTION

1 Brkt Gasket - Pilot Face 10 Locating Pin 19 Idler & Bushing

2 Brkt Gasket - Pilot O.D. 11 Pipe Plugs 20 Head Gaskets

3 Bracket 12 Casing 21 Idler Pin

4 Capscrews for Bracket 13 Capscrew w/Orifice 22 Head & Idler Pin

5 Capscrews for Casing 14 Lockwasher 23 Pipe Plug

6 Pipe Plug 15 Key 24 Capscrews for Head

7 Casing Gasket 16 External Snap Ring 25 Gaskets for Relief Valve

8 Bracket Bushings 17 Rotor & Shaft 26 Relief Valve

9 Balance Plate 18 Idler Bushing 27 Capscrews for Relief Valve

FIGURE 6

EXPLODED VIEW – Q & QS SIZE MAG DRIVE PUMP (QS SHOWN)

ITEM DESCRIPTION ITEM DESCRIPTION ITEM DESCRIPTION

1 Brkt Gasket - Pilot Face 11 Pipe Plugs 21 Head Gaskets

2 Brkt Gasket - Pilot O.D. 12 Casing 22 Idler Pin

3 Bracket 13 Studs for Flanges 23 Head & Idler Pin

4 Capscrews for Bracket 14 Nuts for Flanges 24 Pipe Plug

5 Capscrews for Casing 15 Capscrew w/Orifice 25 Stud for Head

6 Pipe Plug 16 Lockwasher 26 Nuts for Head

7 Bracket Bushings 17 Key 27 Gaskets for Relief Valve

8 Casing Gasket 18 Rotor & Shaft 28 Relief Valve

9 Balance Plate 19 Idler Bushing 29 Capscrews for Relief Valve

10 Locating Pin 20 Idler & Bushing

SECTION TSM 845.1 ISSUE C PAGE 5 OF 13

FIGURE 7

EXPLODED VIEW – D SERIES COUPLING

ITEM DESCRIPTION ITEM DESCRIPTION ITEM DESCRIPTION

1 Locknut 9 Jack Screws 17 Outer Magnet Assembly

2 Lockwasher 10 Set Screws 18 Bracket

3 Endcap 11 Insert 19 Temperature Monitor (Optional)

4 Lip Seals 12 Capscrews, Bearing Housing 20 Pipe Plug

5 Bearing Spacer, Outer 13 Grease Fitting 21 Capscrews for Canister

6 Tapered Roller Bearing, Outer 14 Bearing Housing 22 Canister

7 Bearing Spacer, Inner 15 Gasket, Bearing Housing 23 Washer

8 Tapered Roller Bearing, Inner 16 Key 24 Inner Magnet Assembly

DISASSEMBLY: PUMP

1. See Figure 5 or Figure 6 on page 5 for name of

DANGER !

Before opening any Viking pump liquid
chamber (pumping chamber, reservoir, relief
valve adjusting cap fitting etc.) Be sure:

1. That any pressure in the chamber has
been completely vented through suction
or discharge lines or other appropriate
openings or connections.

2. That the driving means (motor, turbine,
engine, etc.) has been “locked out” or
made non-operational so that it cannot
be started while work is being done on
pump.

3. That you know what liquid the pump
has been handling and the precautions
necessary to safely handle the liquid.
Obtain a material safety data sheet
(MSDS) for the liquid to be sure these
precautions are understood.

Failure to follow above listed precautionary
measures may result in serious injury or
death.

parts.

2. Mark the head, casing and bracket before dis­assembly to insure proper reassembly. The idler pin,
which is offset in pump head, must be positioned
toward and equal distance between port connections
to allow for proper flow of liquid through pump.

3. Unless there appears to be something wrong with the
relief valve (if present), leave assembled and attached
to the pump head. If disassembly is required, refer to

PRESSURE RELIEF VALVES on page 12.

the pump head capscrews (LQ & LS) or the nuts (Q &
QS).

4. Carefully remove the head from the pump. Make
sure the idler does not slide off the idler pin by tilting
the pump head back while removing. Avoid damage
to the head gasket set or O-ring since all gaskets
are required to set end clearance and the O-ring
enhances sealing.

5. Remove the idler and bushing assembly from
idler pin. If the idler bushing needs replacing, see

INSTALLATION OF BUSHINGS on page 9.

Disassembly and inspection of the pump in this
manner is generally sufficient for routine evaluation
of the pump’s condition. If the idler pin and bushing
are original parts and in good condition, usually the
rest of the pump is also in good condition.

Remove

SECTION TSM 845.1 ISSUE C PAGE 6 OF 13

Before further disassembly of the pump can occur, the pump
must be separated from the coupling. Refer to
DISASSEMBLY: MD-D SERIES COUPLING on page 7
before proceeding with step 6.

DISASSEMBLY: MD-D SERIES
COUPLING

6. After the inner magnet is removed from pump shaft,

remove the external snap ring from pump shaft (LQ &
LS only). The rotor and shaft may now be removed by
tapping on the end of shaft with a soft face hammer or, if
using a regular hammer, use a piece of hardwood
between the shaft and hammer.

7. Because the balance plate is designed to be used in
either rotation, mark the balance plate prior to removal.
Remove balance plate by pulling out of casing.

Examine the casing for wear, particularly the area between
the ports. All parts should be cleaned and checked for wear
or damage before pump is assembled.

When making major repairs, such as replacing a rotor and
shaft, it is advisable to also install a new head and idler pin,
idler and bushing, bracket bushings, balance plate and head
gaskets. See INSTALLATION OF BUSHINGS on page 9.

PUMP ROTATION

Viking Mag Drive® pumps are directional. If it is necessary to
rotate in the opposite direction, the pump must be disassembled
through step 7. Rotate the balance plate 180º and reinstall
into the casing. Second, the pipe plug (item 23 for LQ & LS,
item 24 for Q & QS) must be on the suction side of the head.
Remove the pipe plug and reinstall in the other similar hole in
the head Follow the procedure for pump assembly. Reverse
the relief valve orientation so the adjusting cap points towards
suction port.

PORT ARRANGEMENT

CAUTION !

Magnet sets are extremely powerful.

.

Serious injury may result if proper
procedures are not followed.

1. Install the two jackscrews (2-297-022-999) into the
bearing housing. See Figure 7 on page 6, and Figure

8. Remove two 0.50” capscrews and thread a 0.50” NC x

8” threaded rod into these holes. Remove other two 0.50”
capscrews.

FIGURE 8

Standard configuration (as viewed from the pump shaft) is right
angle porting (LQ, LS & Q) – the suction port for clockwise
rotation is at 9 o’clock. The top port (at 12:00) is the standard
discharge port. If the desired configuration is different and
the rotation is still clockwise, mark the suction port, remove
the (8) bracket to casing capscrews and carefully rotate the
casing on the bracket pilot then reinstall the capscrews. The
QS features opposite ports and can not be rotated because
the flanged ports will interfere with the pump bracket foot.

FIGURE 9

FIGURE 10

2. Turn in the two jackscrews evenly, backing the bearing

housing away from the bracket. See Figure 8. Install a
strap from overhead to support the housing and outer
magnet when the housing is approximately 1.50” away
from the bracket. See Figure 9. Continue turning the
jackscrews until the outer assembly comes out freely.
See Figure 10.

SECTION TSM 845.1 ISSUE C PAGE 7 OF 13

3. Set the outer assembly with magnets down on a clean,
flat surface (preferably not steel) to keep from rolling
around. Remove temperature probe (if present).

4. To facilitate disassembly, it may be necessary to slide
a block of wood under the pump casing or clamp pump
foot as shown, since the pump alone will not balance on
foot. See Figure 11. Remove the (4) 0.50” capscrews
securing the pump to the coupling bracket. After parting
the bracket slightly, it will have a tendency to be drawn
to one side due to the inner magnet. Pull the coupling
bracket completely away.

FIGURE 11

7. Insert a brass bar through a port between two rotor teeth

and loosen the capscrew holding the inner magnet onto
the shaft. See Figure 13. The 0.437” capscrew has right
hand threads therefore turn it counterclockwise. THE

INNER MAGNET HAS A VERY STRONG MAGNETIC
FIELD AND IS MOST DANGEROUS IN THE UN­ASSEMBLED CONDITION. THE MAGNET IS QUITE
HEAVY AND WILL BE DRAWN TO ANY FERROUS
OBJECT OR SURFACE CAUSING POTENTIAL
PINCHING. BEWARE OF THE CAUTIONS LISTED
ON (PAGE 3). USE EXTREME CARE SLIDING THE
MAGNET OFF OF THE PUMP SHAFT. SET THE
MAGNET DOWN ON EITHER END AWAY FROM ALL
OTHER OBJECTS. See Figure 14. Remove the key

and the external snap ring (LQ & LS) and then finish
disassembly of the pump.

5. There will probably be some liquid left in the canister so
take the necessary safety precautions. The canister drain
is located behind the mounting flange and near the
underside. Removing plug will drain most of the canister.
Once the liquid has drained, replace the plugs.

6. Remove the (8) 0.375” Allen head capscrews holding the
canister in place then slide the canister off. See Figure

12.

FIGURE 12

FIGURE 13

FIGURE 14

SECTION TSM 845.1 ISSUE C PAGE 8 OF 13

BEARING HOUSING

DISASSEMBLY OF BEARING HOUSING

The bearing housing features two grease packed tapered
roller bearings (TRB) along with a one-piece outer magnet
assembly with shaft. The unit may be greased externally
using the grease fitting. See Figure 15 if further assembly is
required and proceed as follows:

1. Cover the open end of the outer magnet with a piece of
sheet metal. This will keep foreign material out of magnet
area and protect the magnets. Set the assembly face
down with the shaft pointing up and remove jackscrews.

2. Bend the lockwasher tab up and gently tap the locknut in
a counterclockwise direction with a punch until loose. (If
this does not work, place a key into shaft of outer magnet.
Use 1.875” wrench to hold outer magnet and a spanner
wrench to loosen lock nut. Remove the locknut and
lockwasher. Then lift the bearing carrier off the shaft of
the outer magnet assembly.

3. Back out the (2) setscrews holding the bearing cap then
remove the bearing cap with a spanner wrench. The
inner and outer spacers, outer TRB and inner TRB cone
should all slide out of the bearing housing.

4. One lip seal is pressed into the bearing cap and the other
is pressed into the bearing housing. Do not remove
unless replacing.

5. If inner TRB is worn or damaged, remove cup of inner
TRB.

END CAP

BEARING
HOUSING

LIP SEAL

.75 REF

OUTER

SPACER

LOCK NUT

LOCK WASHER

SET SCREWS (2)

OUTER BEARING

INNER SPACER

GREASE FITTING

INNER BEARING

OUTER
MAGNET
ASSEMBLY

COVER END OF MAGNET
WITH PIECE OF SHEET
METAL APPROX. 10” x 10”

FIGURE 15

ASSEMBLY OF BEARING HOUSING

Depending on the condition of the bearings either replace or
recondition existing bearings by cleaning and packing with a
heavy duty grease. Replace the lip seals if necessary.

1. Place the bearing carrier down with the cast surface
up. Install the inner lip seal (if removed). Then install
the cup (if removed) of the inner TRB and the cone into
the bearing housing bore. Insert the inner bearing spacer
(longer one of the two) and the outer TRB into the bore.
Place outer spacer on top of the cone of the outer TRB.

2. The outer end cap houses the second lip seal. If the
seal is in good condition, slide the endcap over the outer
spacer then thread into bearing housing. Center the inner
spacer so the shaft will slide through the two bearings.
Thread in the end cap until it makes contact with the outer
TRB. Tighten the endcap by hand until tight and secure in
position with the (2) setscrews.

3. Insert the outer magnet shaft through the bearings and
the spacers. When the shaft is in the proper position
there should be approximately 0.75” between the magnet
and the housing. See Figure 15.

4. Place the lock washer onto the shaft then thread the
locknut onto the shaft. Tighten locknut to 50 Ft-Lbs then
bend over a lockwasher tab.

5. Tighten the endcap to 75 Ft-lbs and rotate bearing housing
2-3 turns. Back off the end cap and then retighten to 75
Ft-Lbs. Tighten the two .31” setscrews onto the endcap.

Use the grease fitting to fill the bearing chamber with
additional grease.

INSTALLATION OF BUSHINGS

CARBON GRAPHITE:

When installing carbon graphite bushings, extreme care must
be taken to prevent breaking. Carbon graphite is a brittle
material and easily cracked. If cracked, the bushing will quickly
disintegrate. Using a lubricant on the bushing and mating part
will help in installation. The additional precautions listed below
must be followed for installation:

1. An arbor press must be used for installation.

2. Be certain bushing is started straight.

3. Do not stop pressing operation until bushing is in proper

position, starting and stopping will result in cracking
bushing.

4. Check bushing for cracks after installation.

SILICON CARBIDE:

When installing silicon carbide bushings into a metal part
the mating part must be heated to 600ºF (preferably in an
oven). Bushing must be quickly put into the proper position
before the mating part cools down and the bushing heats up.

FAILURE TO FOLLOW THIS PROCEDURE WILL RESULT
IN CRACKED BUSHINGS.

SECTION TSM 845.1 ISSUE C PAGE 9 OF 13

PUMP ASSEMBLY

Use a lubricant compatible with the fluid being handled when
reassembling the pump.

Inspect all parts, replacing any worn parts. Polish out any
nicks or burrs and clean all parts thoroughly. Make sure drilled
holes in rotor, shaft, orifice, balance plate and bracket are
clear. Plugged areas will cause heat buildup and destroy the
magnets. Also check the drilled passageways in the head and
idler pin to be sure they are clear.

1. If the casing was removed from the bracket, place the
O-ring into the groove on back mounting face of casing
(side closest to the hole for the locating pin), and carefully
slide the casing onto the pilot of the bracket and install
capscrews. Install the locating pin into the casing.

2. Place the balance plate into the casing bore with grooved
side out. Orient the groove toward the discharge port.
Push to the bottom of the casing. Line up the notch in
plate with the pin projecting through the casing bore.

3. Insert the shaft gently into the inner bushing bore and
push through until rotor is up against the balance plate.

4. If the old head gaskets are not reusable, refer to Gasket
Table Figure 18. Otherwise, place all head gaskets on
the head. Proper placement of the head is achieved by
the correct number of gaskets. Improper placement will
adversely affect the operation of the pump. The Gasket
Table shows the recommended end clearance and
itemizes the content of gaskets in a set. The O-ring is the
primary seal and should be installed onto the head pilot
after the proper gaskets have been put in place.

FIGURE 16

FIGURE 17

5. Coat the idler pin with suitable lubricant and place the

idler on the idler pin in head.

6. The head can now be assembled on the pump. Tilt the
top of the head away from the pump slightly until the
crescent enters the inside diameter of the rotor and rotate
the idler until its teeth mesh with the rotor teeth. Line up
mark on head and casing, which were previously marked
to insure proper reassembly. Be sure idler pin, which
is offset in pump head, is positioned toward and equal
distance between port connections to allow for proper flow
of liquid through pump. Tighten the head capscrews (or
nuts onto studs in the Q size). Check the end clearance
using a feeler gage as illustrated. See Figure 20 on page

11. If end clearance is not correct, refer to section on
ADJUSTING HEAD GASKET END CLEARANCE on
page 11.

7. Install relief valve if provided and removed.

8. Install the snap ring onto the shaft (not required on Q

size). Apply a lubricant to the canister O-ring and place
into the face groove in the bracket.

GASKET TABLE

NORMAL ➀

END

PUMP MODEL

LQ & LS-825 .008

Q & QS-825 .010

End clearances are adequate for viscosities up to 750 SSU

➀

(SAE 20-lube oil at room temperature). Higher viscosity
liquids require additional end clearances.

As a general guideline, for viscosities between 750 and 7500
SSU (heavier lube oils) add an additional 50% of the end
clearance listed, for viscosities between 7500 and 25,000 SSU
(e.g., resins) double the amount indicated.

For specific recommendations for end clearances for viscosity
or for operating temperatures above 225ºF, check with your
Viking representative or consult the factory.

CLEARANCE

FIGURE 18

ONE SET OF

GASKETS CONSISTS

OF THE FOLLOWING

(1) .015

(2) .007

(2) .005

(1) .015

(2) .007

(3) .005

SECTION TSM 845.1 ISSUE C PAGE 10 OF 13

ADJUSTING HEAD GASKET END
CLEARANCE

Use either of the following procedures to properly adjust the
end clearance, when replacing gaskets.

PROCEDURE A:

With the casing secured to the bracket and balance plate in
position, slide the rotor and shaft into the casing. Insert the
feeler gage of the proper thickness into the port and between
two rotor teeth. Install one .015” and .007” gasket onto the
head. With the idler on idler pin, place head into the pump
casing. With capscrews tight, the feeler gage should fit snugly;
otherwise gaskets should be added or removed until the
proper clearance is attained. See Figure 19.

ASSEMBLY: D SERIES COUPLING

1. Remove any foreign material attached to the magnets.

Place key in pump shaft and slide inner magnet on shaft
until it comes to rest against shoulder on shaft. Insert
washer, lockwasher and capscrew into end of magnet
and tighten. May require inserting brass bar into port to
block rotor from turning. Install O-ring into face of pump
bracket then slide canister over inner magnet and secure
with the capscrews.

DANGER !

Follow these directions exactly to avoid
injury to self or damage to pumping unit,
be extremely careful to keep inner & outer
magnets at least (1) foot apart until step

3. Do not allow magnets to engage in any
other fashion. Be aware of health hazards
listed on (page 2).

2. Place a spacer under pump so the foot sits flat and clamp

foot to the table. Install one of the secondary O-Ring
seals onto the pump pilot then slide the coupling bracket
up to pump and bolt together.

FIGURE 19

PROCEDURE B:

If the pump is in the pipeline and not accessible through ports,
remove the head and remove gaskets. Put the head back
on and measure the gap as shown. See Figure 20. After
determining the gap between head and casing, select a
combination of gaskets with approximately 25% more total
thickness than the feeler gage plus required end clearance.
See Figure 18 on page 10. Note: gaskets will compress
when head is tightened down. Remove head, install all
gaskets and the O-ring, and then install head. Tighten the
head capscrews and then check the pump by making sure
the pump turns over freely by hand.

3. Install two threaded rods into the bracket on the other
end. Insert the (2) jackscrews into their holes of the
bearing housing and thread in completely. Install other
secondary O-ring onto the bearing housing pilot. Support
the bearing housing assembly from over head then slide
onto the (2) threaded rods. Balance the assembly and
glide outer magnet onto canister until jackscrews come
to rest in the two counter bored holes on the bracket. BE

CAREFUL TO CENTER THE OUTER MAGNET WHILE
STARTING TO ENGAGE CANISTER. Depending

on lengths of magnets the unit may be drawn in as the
jackscrews are removed or may require pushing in.
Evenly back off the jack screws until the housing is
approximately 1” from the bracket then remove the over
head support and finish backing off the jack screws. The
housing may require a slight lift to get into the pilot of the
bracket. Secure with (2) capscrews then remove the rods
and install final (2) capscrews.

DANGER !

Before starting pump, be sure all drive
equipment guards are in place.

Failure to properly mount guards may
result in serious injury or death.

FIGURE 20

SECTION TSM 845.1 ISSUE C PAGE 11 OF 13

TROUBLESHOOTING

PRESSURE RELIEF VALVES

Some of the following may help pinpoint the problem:

Pump does not pump:

• Pump has lost its prime from air leak or low level in tank.

• Suction lift is too high

• Pump is rotating in the wrong direction

• Suction and/or discharge valves not open.

• The strainer may be clogged.

• The bypass valve is open, the pressure relief valve is set
too low or the pressure relief valve poppet stuck open.

• Improper end clearance

• The pump is worn out.

• Are there any changes in liquid, system or operation that
would influence pump or coupling performance, e.g. new
liquid, additional lines or process changes?

• Temperature changes either in the liquid or the
environment.

• The magnetic coupling is decoupling. Changes in
application (temperature, pressure, viscosity, etc.) may
require torque beyond coupling capabilities.

Pump starts, then loses its prime:

• The supply tank is empty

• Liquid vaporizing in the suction line

• An air leak or air pocket in the suction line.

Pump is noisy:

• Pump is being starved (heavy liquid cannot get to pump
fast enough). Increase suction pipe size, reduce its length
or slow down the pump.

• Pump is cavitating (liquid vaporizing in suction line).
Increase suction pipe size or reduce its length.

• Check alignment.

• The magnetic coupling has decoupled. Shut off and restart.

Pump is not delivering up to capacity:

• The pump is starving or cavitating – increase suction pipe
size or reduce length or reduce pump speed.

• The strainer is partially clogged.

• An air leak somewhere in suction line.

• The pump may be running too slow. Is motor the correct
speed and wired up correctly?

• The pressure relief valve is set too low, stuck open or has
a damaged poppet or seat.

• The bypass line around the pump is partially open.

• The pump is worn out or has too many gaskets.

PRESSURE ADJUSTMENT

If a new spring is installed or if pressure setting of pressure
relief valve is to be changed from that which the factory has
set, the following instructions must be carefully followed.

1. Carefully remove the valve cap, which covers adjusting
screw. Loosen locknut, which locks adjusting screw
so pressure setting will not change during operation of
pump.

2. Install a pressure gauge in discharge line for actual
operating adjustment.

3. Turn adjusting screw in to increase pressure and out to
decrease pressure.

4. With discharge line closed at a point beyond pressure
gauge, gauge will show maximum pressure valve will
allow while pump is in operation.

FIGURE 21

LIST OF PARTS

1. Valve Cap 6. Valve Body

2. Adjusting Screw 7. Valve Spring

3. Lock Nut 8. Poppet

4. Spring Guide 9. Cap Gasket

5. Bonnet 10. Bonnet Gasket

Pump takes too much power (stalls motor):

• The liquid is more viscous than the unit is sized to handle.

• The system pressure relief valve is set too high.

• The coupling is misaligned.

• The bushings have frozen up or the liquid has set up in
the coupling.

SECTION TSM 845.1 ISSUE C PAGE 12 OF 13

IMPORTANT: In ordering parts for pressure relief valve, always
give model number and serial number of pump as it appears on
nameplate and name of part wanted. When ordering springs,
be sure to give pressure setting desired.

TECHNICAL SERVICE MANUAL

DISASSEMBLY: RELIEF VALVE

DANGER !

SECTION TSM 845.1

PAGE 13 OF 13

ISSUE C

Before opening any Viking pump liquid
chamber (pumping chamber, reservoir,
relief valve adjusting cap fitting, etc.)
be sure:

1. That any pressure in the chamber has
been completely vented through the
suction or discharge lines or other
appropriate openings or connections.

2. That the driving means (motor, turbine,
engine, etc.) has been “locked out” or
made non-operational so that it cannot
be started while work is being done on
pump.

3. That you know what liquid the pump
has been handling and the precautions
necessary to safely handle the liquid.
Obtain a material safety data sheet
(MSDS) for the liquid to be sure these
precautions are understood.

Failure to follow above listed
precautionary measures may result in
serious injury or death.

Mark valve and head before disassembly to insure proper
reassembly.

1. Remove valve cap.

2. Measure and record length of extension of adjusting
screw. Refer to “A” on Figure 21 on page 12.

WARRANTY

Viking warrants all products manufactured by it to
be free from defects in workmanship or material for a
period of one (1) year from date of startup, provided
that in no event shall this warranty extend more than
eighteen (18) months from the date of shipment from
Viking. If, during said warranty period, any products
sold by Viking prove to be defective in workmanship
or material under normal use and service, and if such
products are returned to Viking’s factory at Cedar Falls,
Iowa, transportation charges prepaid, and if the products
are found by Viking to be defective in workmanship
or material, they will be replaced or repaired free of
charge, FOB. Cedar Falls, Iowa.

Viking assumes no liability for consequential
damages of any kind and the purchaser by acceptance
of delivery assumes all liability for the consequences of
the use or misuse of Viking products by the purchaser,
his employees or others. Viking will assume no field
expense for service or parts unless authorized by it in
advance.

Equipment and accessories purchased by Viking
from outside sources which are incorporated into any
Viking product are warranted only to the extent of and
by the original manufacturer’s warranty or guarantee,
if any.

THIS IS VIKING’S SOLE WARRANTY AND IS IN
LIEU OF ALL OTHER WARRANTIES, EXPRESSED
OR IMPLIED, WHICH ARE HEREBY EXCLUDED,
INCLUDING IN PARTICULAR ALL WARRANTIES
OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. No officer or employee of
IDEX Corporation or Viking Pump, Inc. is authorized to
alter this warranty.

3. Loosen locknut and back out adjusting screw until spring
pressure is released.

4.

Remove bonnet, spring guide, spring and poppet from
valve body. Clean and inspect all parts for wear or
damage and replace as necessary.

ASSEMBLY: RELIEF VALVE

Reverse procedures outlined under Disassembly. If valve is
removed for repairs, be sure to replace in original position.
Relief valve adjusting screw cap must always point toward
suction side of pump. If pump rotation is reversed, remove
relief valve and turn end for end. See Figure 3 on page 3.
Also refer to PUMP ROTATION on page 7.

VIKING PUMP, INC. • A Unit of IDEX Corporation • Cedar Falls, IA 50613 USA

DANGER !

Before starting pump, be sure all drive
equipment guards are in place.

Failure to properly mount guards may
result in serious injury or death.

© 5/2007 Viking Pump Inc.
All rights reserved