Goulds Pumps 3408 User Manual

I

nstallation, Operation and Maintenance Instructions

Model 3408

© 1999 Goulds Pumps

Pump Safety Tips

Safety Apparel:

Insulated work gloves when handling hot bearings

•

or using bearing heater
Heavy work gloves when handling parts with sharp

•

edges, especially impellers
Safety glasses (with side shields) for eye

•

protection, especially in machine shop areas
Steel-toed shoes for foot protection when handling

•

parts, heavy tools, etc.
Other personal protective equipment to protect

•

against hazardous/toxic fluids

Coupling Guards:

Never operate a pump without a coupling guard

•

properly installed

Flanged Connections:

Never force piping to make a connection with a pump

•

Use only fasteners of the proper size and material

•

Operation:

Do not operate below minimum rated flow, or with

•

suction/discharge valves closed
Do not open vent or drain valves, or remove plugs

•

while system is pressurized

Maintenance Safety:

Always lock out power

•

Ensure pump is isolated from system and pressure

•

is relieved before disassembling pump, removing
plugs, or disconnecting piping

Use proper lifting and supporting equipment to

•

prevent serious injury
Observe proper decontamination procedures

•

Know and follow company safety regulations

•

Observe all cautions and warnings highlighted in
pump Installation, Operation and Maintenance

Instructions.

Ensure there are no missing fasteners

•

Beware of corroded or loose fasteners

•

FOREWORD

3408 IOM 03/99 3

This manual provides instructions for the Installation, Operation, and Maintenance of the
Goulds Model 3408 Double Suction, Horizontally Split Case Pump. This manual covers the
standard product plus common options that are available. For special options, supplemental
instructions are supplied. This manual must be read and understood before installation

and maintenance.

The design, materials, and workmanship incorporated in the construction of Goulds pumps
make them capable of giving long, trouble-free service. The life and satisfactory service of any
mechanical unit, however, is enhanced and extended by correct application, proper
installation, periodic inspection, condition monitoring and careful maintenance. This instruction
manual was prepared to assist operators in understanding the construction and the correct
methods of installing, operating, and maintaining these pumps.

ITT Industries - Goulds Pumps shall not be liable for physical injury, damage or delays
caused by a failure to observe the instructions for Installation, Operation, and
Maintenance contained in this manual.

Warranty is valid only when genuine ITT Industries - Goulds Pumps parts are used.

Use of the equipment on a service other than stated in the order will nullify the warranty,
unless written approval is obtained in advance from ITT Industries - Goulds Pumps.

Supervision by an authorized ITT Industries - Goulds representative is recommended to
assure proper installation.

Additional manuals can be obtained by contacting your local ITT Industries - Goulds
representative or by calling 1-(800)-446-8537.

THIS MAN UAL EX PLAINS

Proper In stal la tion

n

Start- up Pro ce dures

n

Op era tion Pro ce dures

n

Rou tine Main te nance

n

Pump Over haul

n

Trou ble shoot ing

n

Or der ing Spare or Re pair Parts

n

4 3408 IOM 03/99

TABLE OF CONTENTS

3408 IOM 03/99 5

SECTION

PAGE

7 SAFETY

1

9 GENERAL INFORMATION

11 INSTALLATION

23 OPERATION

27 PREVENTIVE MAINTENANCE

35 DISASSEMBLY & REASSEMBLY

57 APPENDIX

2

3

4

5

6

7

6 3408 IOM 03/99

SAFETY

3408 IOM 03/99 7

DEFI NI TIONS .................................. 7

GEN ERAL PRE CAU TIONS ........................... 7

DEFINITIONS

1

This pump has been designed for safe and reliable
operation when properly used and maintained in
accordance with instructions contained in this manual.
A pump is a pressure containing device with rotating
parts that can be hazardous. Operators and
maintenance personnel must realize this and follow
safety measures. ITT Industries - Goulds Pumps
shall not be liable for physical injury, damage or
delays caused by a failure to observe the instructions
in this manual.

Throughout this manual the words WARNING ,
CAUTION , and NOTE are used to indicate
procedures or situations which require special
operator attention:

! WARNING

▲

Warning is used to indicate the presence of a
hazard which can cause severe personal injury,
death, or substantial property damage if the
warning is ignored.

▲!

Caution is used to indicate the presence of a
hazard which will or can cause minor pe rsonal
injury or property damage if the warning
is ignored.

NOTE: Operating procedure, condition, etc.
which is essential to observe.

CAUTION

EXAMPLES

! WARNING

▲

Pump shall never be operated without coupling
guard installed correctly.

▲!

Throttling flow from the suction side may
cause cavitation and pump damage.

NOTE: Proper alignment is essential for long
pump life.

CAUTION

GENERAL PRECAUTIONS

! WARN ING

▲

Personal injuries will result if procedures
outlined in this manual are not followed.

NEVER operate pump without coupling guard

•

correctly installed.
NEVER operate pump beyond the rated conditions

•

to which the pump was sold.
NEVER start pump without proper prime (sufficient

•

liquid in pump casing).
NEVER run pump below recommended minimum

•

flow or when no liquid is in pump.
ALWAYS lock out power to the driver before

•

performing pump maintenance.
NEVER operate pump without safety devices installed.

•

NEVER operate pump with discharge valve closed.

•

NEVER operate pump with suction valve closed.

•

DO NOT change conditions of service without

•

approval of an authorized Goulds representative.

! Warn ing

▲

If pump is to be used on process fluids above
120° F, pump surface temperatures could be
warm enough to cause burns. We recommend
pump surfaces be insulated. Failure to follow
these instructions could result in severe
personal injury.

8 3408 IOM 03/99

GENERAL INFORMATION

3408 IOM 03/99 9

PUMP DE SCRIP TION .............................. 9

NAME PLATE IN FOR MA TION ......................... 10

PUMP DESCRIPTION

2

This product line consists of 39 sizes of double
suction, horizontally split case pumps from size
2 x 3-11 through size 10 x 12-18.

Casing - The casing shall be (close-grained cast iron
for working pressures up to 175 psig), (ductile iron for
working pressures up to 400 psig), and shall be of
axially-split design with suction and discharge flanges
and mounting feet cast integral with the lower half
casing. Tapped and plugged holes shall be provided
for priming, vent drain and gauge connections. Upper
half casing shall be removable without disturbing
suction or discharge piping. Flanges shall be of (125#)
(250#) ASA Standard. Suction and discharge shall be
on a common centerline in both the horizontal and
vertical planes.

Impeller - The impeller shall be of the enclosed
double suction type made of bronze non-overloading
in operating characteristics and statically and
hydraulically balanced. The impeller shall be keyed to
the shaft and positioned axially by the shaft sleeves
which are, in turn, locked in place by shaft nuts. Hub
shall have sufficient metal thickness to allow
machining for installation of impeller rings.

Shaft - The shaft shall be made of ( SAE-1045 steel
(316 stainless steel
steel) of ample size to operate under load with a
minimum of deflection.

Shaft Sleeves - The Shaft Sleeves shall be made of
(bronze) (316 stainless steel) (cast iron) (420
stainless steel, 500 Brinnell ) and shall protect the
shaft from wear and from contact with the pumped
liquid. Shaft sleeves shall be locked in place by
threaded, bronze shaft sleeve nuts. An O-ring shall be
furnished under sleeve to prevent leakage.

•) (heat treated 416 stainless

•)

Stuffing Box Housing / Bearing Brackets - The
Stuffing Box Housing / Bearing Brackets shall be
made of cast iron separate from the casing mounted
in cylindrical fits in the casing. Stuff box/bearing
brackets will be drilled and tapped for drain
connection.

Casing Rings - The casing rings shall be made of
(bronze) (cast iron) ( Nitronic 60 stainless steel) and
shall be installed with an anti-rotation device and
designed to restrict leakage across the ring fit.

Bearings - The bearing shall be grease lubricated (oil
optional) ball type, single row inboard, double row
outboard, selected to carry radial and thrust loads.
The outboard bearing shall be retained by bearing
locknut and lockwasher.

Bearing Housings - The bearing housings shall be
bolted to the ends of the bearing bracket/stuffing box
and shall be male-female fitted for a full 360 degrees
to assure positive alignment. The housings shall
provide a fit for the inboard bearing that allows
freedom for thermal expansion while the outboard
bearing shall be clamped in place to take all thrust
loads and keep the rotating element in its proper axial
location. Openings for adding new grease and
draining old grease shall be provided.

Baseplate - The baseplate shall be steel, sufficiently
rigid to support the pump and driver.

Coupling - Coupling shall be of the flexible type.
Coupling hubs shall be secured to the driver and
driven shafts by a setscrew located over the key.

Coupling Guard - The coupling guard shall be the all
metal type.

Rotation - Pump shall have clockwise or
counterclockwise rotation when viewed from its
driven end.

• AISI 4140 Steel is standard on 4 x 6-11, 6 x 8-12M, and 8 x 10-20S & L, 10 x 12-18. 1045 & 316SS are no t available for these sizes.

NAMEPLATE INFORMATION

Every pump has a Goulds nameplate that provides
information about the pump. The nameplate is located
on the pump casing.

Special tags which provide additional information
(mechanical seal data, etc.) and special tagging
required by customers are located on the pump
casing or on the bearing frame.

The standard nameplate (Fig. 1) provides information
about the pump size, type, serial number, rated head,
capacity, speed, impeller diameter, model number,
and maximum field hydrostatic test pressure.

The identification No. is a number which the end user
of pump requests to be put on the nameplate to
identify the pump in his operation.

The year indicates the year in which the pump was
built.

Rating and hydrostatic test pressure are expressed in
English units. Note the format of pump size:
Discharge x Suction - Nominal Impeller Diameter in
inches, for example, 2 x 3-11.

The frame plate (Fig. 2) provides information
concerning the bearings and their lubrication. The
inboard and outboard bearing numbers refer to the
bearing manufacturer’s numbers.

When ordering spare parts you will need to identify
pump model, size, serial number, and the catalog
number of required parts. Pump information can be
taken from the Goulds nameplate. Catalog numbers
can be found in this manual (Pg. 66).

Fig. 1

Fig. 2

10 3408 IOM 03/99

INSTALLATION

3408 IOM 03/99 11

RE CEIVING THE PUMP ............................ 11

LIFTING THE PUMP .............................. 11

Hor i zon tal .................................. 11

Ver ti cal ................................... 12

STOR AGE ................................... 13

Tem po rary ................................. 13

Long Term ................................. 13

LO CA TION ................................... 14

FOUN DA TION ................................. 14

SETTING THE BASE PLATE ......................... 14

Grouting Pro ce dure ............................. 15

ALIGN MENT PRO CE DURE .......................... 15

Method One ................................. 16

Method Two ................................. 16

DOWELING .................................. 17

SUC TION AND DIS CHARGE PIPING ..................... 17

Suc tion Pip ing ................................ 17

Dis charge Pip ing .............................. 19

Pres sure Gauges .............................. 19

STUFFING BOX LU BRI CA TION ....................... 20

Packing ................................... 20

Me chan i cal Seals .............................. 21

Cartridge Seals ............................... 21

Cy clone Separators ............................. 21

3

RECEIVING THE PUMP

Check pump for shortages and damage immediately
upon arrival. (An absolute must!) Prompt reporting to
the carrier’s agent, with notations made on the freight
bill, will expedite satisfactory adjustment by the
carrier.

Pumps and drivers are normally shipped from the
factory mounted on a baseplate. Couplings may either

LIFTING THE PUMP

The following instructions are for the safe lifting of
your pump.

The unit should be unloaded and handled by lifting
equally at four or more points on the baseplate. The
lugs on the upper half casing are designed for lifting
the upper half casing only.

be completely assembled or have the coupling hubs
mounted on the shafts and the connecting members
removed. When the connecting members are
removed, they will be packaged in a separate
container and shipped with the pump or attached to
the baseplate.

HORIZONTAL

Bare Pump (Model 100)

1. Using a nylon sling, chain, or wire rope, hitch
around both bearing housings. (See Fig. 3)

12 3408 IOM 03/99

DO NOT LIFT
ENTIRE PUMP
WITH THESE
LUGS.

Pump, Base, and Driver (Model 150)

2. Care must be taken to size equipment for
unbalanced loads which may exist if the driver is
not mounted on the base at the time of lifting.
Driver may or may not be mounted at the factory.

Fig. 3

Using ANSI/OSHA Standard “S” hooks, place the “S”
hooks in the holes provided in the four corners of the base.
Be sure the points of the hooks do not touch the bottom of
the pump base. Attach nylon slings, chains, or wire rope to
the “S” hooks. Size the equipment for the load, and so the
lift angle will be less than 45° from the vertical.

Bases supplied without lifting holes

Place one sling around the outboard bearing housing.

! WARN ING

▲

Do not use lugs on top half of casing.

Place the remaining sling around the back end of the driver
as close to the mounting feet as possible. Make certain
sling will not damage housing cover or conduit boxes.

Join the free ends of the slings together and place over
the lifting hook. Use extreme care when positioning sling
under the driver so it cannot slip off. (See Fig. 5)

3. Pump, base, and driver assemblies where the
base length exceeds 100 inches may not be safe
to lift as a complete assembly. Damage to the
baseplate may occur. If the driver has been
mounted on the baseplate at the factory, it is safe
to lift the entire assembly. If driver has not been
mounted at the factory and the overall baseplate
length exceeds 100 inches, do not lift entire
assembly consisting of pump, base, and driver.
Instead lift the pump and baseplate to its final
location without the driver. Then mount the driver.

Bases supplied with lifting holes

Large bases are supplied with lifting holes in the
sides or the ends of the base. (See Fig. 4)

Fig. 5

VERTICAL

Half Pedestal (Model 200)

1. Place nylon sling chain or wire rope around both
flanges. Use a latch hook or standard shackle and
end loops.

Be sure the lifting equipment is of sufficient length
to keep the lift angle less than 30° from the
vertical. (See Fig. 6)

Fig. 4

Fig. 6

3408 IOM 03/99 13

Full Pedestal (Model 300)

2. Install eyebolts in the three holes provided at the top of
the support, being sure to tighten securely. Attach
chain or wire rope using latch hook or standard shackle
and end loop.

Be sure to use shoulder eyebolts that are
manufactured per ANSI B18.15 and sized to fit the
holes provided.

Be sure lifting equipment is of sufficient length to
keep the lift angle less than 30° from the vertical.
(See Fig. 7)

STORAGE

Fig. 7

3

The following storage procedures apply to the pump
only. Other accessories such as motors, steam
turbines, gears, etc., must be handled per the
respective manufacturer’s recommendations.

TEMPORARY

Temporary storage is considered one month or less.
If the pump is not to be installed and operated soon
after arrival, store it in a clean, dry place having slow,
moderate changes in ambient temperature. Rotate the
shaft periodically to coat the bearings with lubricant
and to retard oxidation, corrosion, and to reduce the
possibility of false brinelling of the bearings. Shaft
extensions and other exposed machine surfaces
should be coated with an easily removable rust
preventative such as Ashland Oil Tectyl No. 502C.

For oil lubricated bearings, fill the frame completely
with oil. Before putting equipment into operation, drain
the oil and refill to proper level.

LONG TERM

Storage longer than one month is considered long
term storage. Follow the same procedure for
temporary storage with the following addition. Add
one half ounce of a corrosion inhibiting concentrated
oil such as Cortec Corp. VCI-329 (for both grease and
oil lubricated bearings). Seal all vents and apply a
water proof tape around the oil seals in the bearing
frame. Remember for oil lubricated bearings to drain
the oil from the frame and refill to the proper level
before running pump.

14 3408 IOM 03/99

LOCATION

The pump should be installed as near the suction
supply as possible, with the shortest and most direct
suction pipe practical. The total dynamic suction lift
(static lift plus friction losses in suction line) should not
exceed the limits for which the pump was sold.

The pump must be primed before starting. Whenever
possible, the pump should be located below the fluid
level to facilitate priming and assure a steady flow of
liquid. This condition provides a positive suction head
on the pump. It is also possible to prime the pump by
pressurizing the suction vessel.

When installing the pump, consider its location in
relation to the system to assure that sufficient Net
Positive Suction Head (NPSHA) is available at the
pump inlet connection. Available NPSH must always
equal or exceed the required NPSH ( NPSHR ) of the
pump.

FOUNDATION

The foundation must be substantial enough to absorb
vibration. ( Hydraulic Institute Standards recommends
the foundation weigh at least five (5) times the weight of
the pump unit.) It must form a permanent and rigid
support for the baseplate. This is important in
maintaining the alignment of a flexibly coupled unit.

The pump should be installed with sufficient accessibility
for inspection and maintenance. A clear space with ample
head room should be allowed for the use of an overhead
crane or hoist sufficiently strong to lift the unit.

NOTE: Allow sufficient space to be able to
dismantle pump without disturbing the pump inlet
and discharge piping.

Select a dry place above the floor level wherever
possible. Take care to prevent pump from freezing during
cold weather when not in operation. Should the possibility
of freezing exist during a shut-down period, the pump
should be completely drained, and all passages and
pockets where liquid might collect should be blown out
with compressed air.

Make sure there is a suitable power source available for
the pump driver. If motor driven, the electrical
characteristics of the power source should be identical to
those shown on motor data plate.

The foundation should be poured to within .75" - 1.5"
of the finished height. (See Fig. 8) Freshly poured
foundations should be allowed to cure for several
days before the unit is set in place and grouted.

Foundation bolts of the proper size should be embedded
in the concrete to a depth of eight (8) to twelve (12)
inches and locked with either a hook around a
reinforcing bar or alternatively, a nut and washer at the
bottom. The bolts should have a sleeve around them at
least six (6) times the bolt diameter in length and at least
two (2) bolt sizes larger in I.D. If a nut and washer are
used for locking, the washer should have an O.D. two
(2) sizes larger than the sleeve. Foundation bolts should
be sized .125" less than the anchor bolt holes in the
base.

SETTING THE BASEPLATE

Pump units are checked at the factory for align ability to
required tolerances.

Due to flexibility of an ungrouted base and handling in
shipment, it should not be assumed that the unit is in
alignment when it is placed on the rough foundation.

If these directions are followed, the required alignment
should be readily achieved.

Fig. 8

Initial or rough alignment must be done prior to grouting of
baseplate. Rough alignment is designated as .020" TIR
(Total Indicator Reading) parallel alignment and .009" TIR
per inch of radius angular alignment (See ALIGNMENT
PROCEDURE). Use blocks at anchor bolts and midway
between to position bottom of base at finished height
(See Fig. 9) with foundation bolts extending through holes
in the baseplate. Metal wedges with a small taper may be
used in lieu of blocks and shims.

3408 IOM 03/99 15

NOTE: The baseplate does not have to be level.

After foundation bolts are lightly torqued , recheck
alignment requirements once more. Follow
requirements outlined at the beginning of this section.
If alignment must be corrected, add or remove shims
or wedges under the baseplate.

The unit can then be grouted. (See Fig. 9)
Grout compensates for the uneven foundation.

Together with the baseplate, it makes a very rigid
interface between the pump and the foundation
distributing the weight over the length of the base and
preventing shifting.

Fig. 9

If the unit has a non-flexible coupling (e.g. Falk Gear
coupling), the coupling halves should be disconnected;
this is generally not necessary on flexible type couplings
(e.g. Wood’s Sure-Flex coupling).

Tighten up all pump and motor bolts to assure they have
not loosened or a “soft foot” has occurred due to base
distortion in shipment. A “soft foot” causes a change in
the alignment when unloosening one bolt.

If the driver is being field installed, it should be centered in
its bolt holes with shims added to bring the driver into
rough alignment with the pump. (The pump may have to
be moved also.)

▲! CAUTION

Do not exceed six (6) shims, using as thick a
shim as possible, otherwise “sponginess” or
“soft foot” will result. Place thin shims in
between thick shims.

Level and plumb the pump shaft, coupling faces and
flanges by adding or removing shims between the blocks
and the bottom of the base. Hand tighten the anchor bolt
nuts at first. Being very careful not to distort the base,
snug down the nuts with a wrench. The non-flexible
coupling should not be reconnected until the alignment
operation has been completed.

Use an approved, non-shrinking grout such as
Embeco 636 or 885 by Master Builders, Cleveland,
Ohio or equivalent.

GROUTING PROCEDURE

1. Build a strong form around the foundation to
contain the grout.

2. Soak the top of the foundation thoroughly, then
remove surface water.

3. The baseplate should be completely filled with
grout and, if necessary, temporarily use air relief
tubing or drill vent holes to remove trapped air.

4. After the grout has thoroughly hardened
(approximately 24 hours), tighten the foundation
bolts fully.

5. Check the alignment after the foundation bolts
are tightened.

6. Approximately fourteen (14) days after the grout
has been poured and the grout has thoroughly
dried, apply an oil base paint to the exposed
edges of the grout to prevent air and moisture
from coming in contact with the grout.

3

ALIGNMENT PROCEDURE

Proper rough alignment must be made during unit
setting and grouting. See previous section.

There are two forms of misalignment between the
pump shaft and the driver shaft as follows:

1. Angular misalignment — shafts have axis
concentric at intersection, but not parallel.

2. Parallel offset misalignment — shafts have axis
parallel, but offset.

The necessary tools for checking alignment are: (1) a
straight edge and a taper gauge or set of feeler gauges
or, (2) a dial indicator with mounting magnet and
extension bars.

Check and correct for angular misalignment before
correcting parallel alignment. Final alignment should be
made by moving and shimming the motor on its base until
the coupling hubs are within the recommended tolerances
measured in total run out. All measurements should be

16 3408 IOM 03/99

taken with the pump and driver bolts tightened. Final
alignment check should be made after the unit has
attained its final operating temperature.

Method 1 - Using straight edge and taper gauges or
feelers (Fig. 10):

Proceed with this method only if satisfied that face
and outside diameters of the coupling halves are
square and concentric with the coupling bores. If this
condition does not exist or elastomeric couplings do
not make this method convenient, use Method 2.

Check for angular alignment by inserting the taper or
feeler gauges between the coupling faces at 90°
intervals. The unit is in angular alignment when these
four (4) measurements are the same, or within
recommended tolerances.

Check for parallel alignment by placing a straight
edge across both coupling rims on all four sides. The
unit is in parallel alignment when the straight edge
rests evenly across both coupling rims in all four (4)
positions.

Method 2 - Dial Indicators (Fig. 11):
A dial indicator can be used to attain more accurate

alignment.
Fasten the indicator stand or magnetic base to the

pump half of the coupling and adjust the assembly
until the indicator button is resting on the other half
coupling periphery.

Set the dial to zero and chalk mark the coupling half
where the button rests. Also place a separator
between the coupling halves so bearing slack does
not affect the readings. (Chalk and separators are not
necessary on the elastomeric couplings that have not
been disconnected.) Rotate both shafts by the same
amount; i.e., all readings must be made with the
button on the chalk mark.

The dial readings will indicate whether the driver has
to be raised, lowered or moved to either side.
Accurate alignment of shaft centers can be obtained
with this method even where faces or outside
diameters of the coupling are not square or concentric
with the bores. After each adjustment, recheck both
parallel and angular alignments.

Fig. 10

NOTE: Gross deviations in squareness or
concentricity may cause rotation unbalance
problems and if so must be corrected.

Permissible Coupling Misalignment:
Parallel: Single element coupling:

.004" TIR (4 mils)

Double element (spacer) coupling:

.060" TIR per foot of spacer length

Angular: Single element coupling:

.004" TIP per inch of radius

Double element (spacer) coupling:
.002" TIR per inch of radius

3408 IOM 03/99 17

DOWELING

Fig. 11

3

Pump units may, if desired, (or required in
specification) be doweled on diagonally opposite feet.
This should not be done until the unit has been run for

SUCTION AND DISCHARGE PIPING

The introduction of pumpage into a piping system which is
not well designed or adjusted may cause strain on the
pump, leading to misalignment or even impeller rubbing.
Since slight strain may go unnoticed, final alignment should
be done with the system full and up to final temperature.

Pipe flanges should not impose any strain on the pump.
This can be checked by a dial indicator. Any strain must be
corrected by adjustments in the piping system.

When installing the pump piping, be sure to observe the
following precautions:

Piping should always be run to the pump.
Do not move the pump to pipe. This could make final

alignment impossible.
Both the suction and discharge piping should be

independently anchored near the pump and properly
aligned so that no strain is transmitted to the pump when
the flange bolts are tightened. Use pipe hangers or other
supports at necessary intervals to provide support. When
expansion joints are used in the piping system they must be
installed beyond the piping supports closest to the pump.
Tie bolts and spacer sleeves should be used with
expansion joints to prevent pipe strain. Do not install
expansion joints next to the pump or in any way that would
cause a strain on the pump resulting from system pressure
changes. When using rubber expansion joints, follow the
recommendations of the Technical Handbook on Rubber
Expansion Joints and Flexible Pipe Connectors. It is usually

a sufficient length of time and alignment is within the
above alignment tolerance.

advisable to increase the size of both suction and discharge
pipes at the pump connections to decrease the loss of head
from friction.

Install piping as straight as possible, avoiding unnecessary
bends. Where necessary, use 45° or long radius 90° fittings
to decrease friction losses.

Make sure that all piping joints are air-tight.
Where flanged joints are used, assure that inside diameters

match properly.
Remove burrs and sharp edges when making up joints.
Do not “spring” piping when making any connections.
Provide for pipe expansion when hot fluids are to be

pumped.

Fig. 12

18 3408 IOM 03/99

Suction Piping

When installing the suction piping, observe the following
precautions. (See Fig. 13)

The sizing and installation of the suction piping is
extremely important. It must be selected and installed so
that pressure losses are minimized and sufficient liquid
will flow into the pump when started and operated.

Many NPSH (Net Positive Suction Head) problems
can be directly attributed to improper suction piping
systems.

When installing valves in the suction piping, observe
the following precautions:

1. If the pump is operating under static suction lift
conditions, a foot valve may be installed in the
suction line to avoid the necessity of priming each
time the pump is started. This valve should be of
the flapper type, rather than the multiple spring
type, sized to avoid excessive friction in the
suction line. (Under all other conditions, a check
valve, if used, should be installed in the discharge
line. See Discharge Piping.)

Suction piping should be short in length, as direct as
possible, and never smaller in diameter than the
pump suction opening. A minimum of five (5) pipe
diameters between any elbow or tee and the pump
should be allowed. If a long suction pipe is required, it
should be one or two sizes larger than the suction
opening, depending on its length.

▲! CAUTION

An elbow should not be used directly before the
suction of a double suction pump if its plane is
parallel to the pump shaft. This can cause an
excessive axial load or NPSH problems in the pump
due to an uneven flow distribution. (See Fig. 12) If
there is no other choice, the elbow should have
straightening vanes to help evenly distribute the
flow.

Eccentric reducers should be limited to one pipe size
reduction each to avoid excessive turbulence and
noise. They should be of the conical type. Contour
reducers are not recommended.

When operating on a suction lift, the suction pipe
should slope upward to the pump nozzle. A horizontal
suction line must have a gradual rise to the pump.
Any high point in the pipe can become filled with air
and prevent proper operation of the pump. When
reducing the piping to the suction opening diameter,
use an eccentric reducer with the eccentric side down
to avoid air pockets.

2. When foot valves are used, or where there are
other possibilities of “water hammer”, close the
discharge valve slowly before shutting down the
pump.

3. Where two or more pumps are connected to the
same suction line, install gate valves so that any
pump can be isolated from the line. Gate valves
should be installed on the suction side of all
pumps with a positive pressure for maintenance
purposes. Install gate valves with stems
horizontal to avoid air pockets. Globe valves
should not be used, particularly where NPSH is
critical.

4. The pump must never be throttled by the use of a
valve on the suction side of the pump. Suction
valves should be used only to isolate the pump
for maintenance purposes, and should always be
installed in positions to avoid air pockets.

3

NOTE: When operating on suction lift never
use a concentric reducer in a horizontal
suction line, as it tends to form an air pocket in
the top of the reducer and the pipe.

Fig. 13 shows some correct and incorrect suction
piping arrangements.

3408 IOM 03/99 19

Discharge Piping

If the discharge piping is short, the pipe diameter can
be the same as the discharge opening. If the piping is
long, the pipe diameter should be one or two sizes
larger than the discharge opening. On long horizontal
runs, it is desirable to maintain as even a grade as
possible. Avoid high spots, such as loops, which will
collect air and throttle the system or lead to erratic
pumping.

A check valve and an isolating gate valve should be
installed in the discharge line. The check valve,
placed between pump and gate valve, protects the
pump from excessive back pressure, and prevents
liquid from running back through the pump in case of
power failure. The gate valve is used in priming and
starting, and when shutting the pump down.

Pressure Gauges

Properly sized pressure gauges should be installed in
both the suction and discharge nozzles in the gauge
taps provided. The gauges will enable the operator to
easily observe the operation of the pump, and also
determine if the pump is operating in conformance
with the performance curve. If cavitation, vapor
binding, or other unstable operation should occur,
widely fluctuating discharge pressure will be noted.

3

Fig. 13

20 3408 IOM 03/99

STUFFING BOX LUBRICATION

Contaminants in the pumped liquid must not enter the
stuffing box. These contaminants may cause severe
abrasion or corrosion of the shaft, or shaft sleeve, and
rapid packing or mechanical seal deterioration; they
can even plug the stuffing box flushing and lubrication
system. The stuffing box must be supplied at all times
with a source of clean, clear liquid to flush and
lubricate the packing or seal. The most important
consideration is to establish the optimum flushing
pressure that will keep contaminants from the stuffing
box cavity. If this pressure is too low, fluid being
pumped may enter the stuffing box. If the pressure is
too high, excessive packing or seal wear may result;
and extreme heat may develop in the shaft causing
higher bearing temperatures. The most desirable
condition, therefore, is to use a seal water pressure
15-20 psig above the maximum stuffing box pressure.

If the pump system pressure conditions vary, packing
adjustment becomes difficult. Consideration should be
given to using a mechanical seal. (See Mechanical
Seals.)

Packing

Standard pumps are normally packed before ship­ment . If the pump is installed within 60 days after
shipment, the packing will be in good condition with a
sufficient supply of lubrication. If the pump is stored
for a longer period, it may be necessary to repack the
stuffing box. In all cases, however, inspect the
packing before the pump is started.

NOTE: Packing adjustment is covered in the
MAINTENANCE SECTION of this manual.

On some applications, it is possible to use internal
liquid lubrication (pumped liquid) to lubricate packing.
Only when all of the conditions prevail, can this be
done:

1. Liquid is clean, free from sediment and chemical
precipitation and is compatible with seal
materials.

2. Temperature is above 32° F and below 160° F.

3. Suction pressure is below 75 psig .

4. Lubrication (pumped liquid) has lubricating
qualities.

5. Liquid is non-toxic and non-volatile.

When the liquid being pumped contains solids or is
otherwise not compatible with packing materials, an
outside supply of seal liquid should be furnished. In
general, external-injection liquid (from an outside
source) is required when any of the above conditions
cannot be met.

The standard stuffing box consists of rings of packing
(see assembly section for number of rings), a seal
cage (optional), and a gland. A shaft sleeve which
extends through the box and under the gland is
provided to protect the shaft.

A tapped hole is supplied in the stuffing box directly
over the seal cage to introduce a clean, clear sealing
medium. The stuffing box must, at all times, be
supplied with sealing liquid at a high enough pressure
to keep the box free from foreign matter, which would
quickly destroy the packing and score the shaft
sleeve.

Only a sufficient volume of sealing liquid to create a
definite direction of flow from the stuffing box inward
to the pump casing is required, but the pressure is
important. Apply seal water at a rate of approximately
.25 GPM at a pressure approximately 15 to 20 psig
above the suction pressure. (Approximately one (1)
drop per second.)

One recommended method to minimize error in
regulating flushing water is a “Controlled Pressure
System.” (Fig. 14) Most important is the pressure
reducing valve adjusted to a value slightly exceeding
the maximum stuffing box operating pressure
(assuming it is reasonably constant). A flow indicating
device will serve to indicate a failing of the bottom
packing rings allowing leakage in the pump.

External sealing liquid should be adjusted to the point
where the packing runs only slightly warm, with a very
slow drip from the stuffing box. Excess pressure from
an external source can be very destructive to packing.
More pressure is required, however, for abrasive
slurries than for clear liquids. Examination of the
leakage will indicate whether to increase or decrease
external pressure. If slurry is present in the leakage,
increase the pressure until only clear liquid drips from
the box. If the drippage is corrosive or harmful to
personnel, it should be collected and piped away.

A common error is to open the external piping valve
wide and then control the drippage by tightening the
packing gland. Actually, a combination of both
adjustments is essential to arrive at the optimum
condition. The life of packing and sleeve depends on
this careful control more than any other factor.

3408 IOM 03/99 21

Pump
Casing

Fig. 14

Mechanical Seals

Mechanical seals are preferred over packing on some
applications because of better sealing qualities and
longer serviceability. Leakage is eliminated when a
seal is properly installed, and normal life is much
greater than that of packing on similar applications. A
mechanical shaft seal is supplied in place of a packed
stuffing box when specifically requested. The change
from packing to an alternate arrangement may be
made in the field by competent service personnel.
Conversion parts may be ordered from your Goulds
Pump Sales Representative.

Just as with packing, the mechanical seal chamber
must be supplied, at all times, with a source of clean,
clear liquid to flush and lubricate the seal. The most
important consideration is to establish the optimum
flushing pressure that will keep contaminants from the
seal cavity. If this pressure is too low, fluid being
pumped may enter the stuffing box. If the pressure is
too high, excessive seal wear may result.

When contaminants are present in the pumpage, an
external source of clean seal water must be supplied.
Supply approximately .25 GPM at a pressure
approximately 15 to 20 psig above the suction
pressure.

Fig. 14 shows the recommended “Controlled Pressure
System” for a mechanical seal. Seal water enters the
seal chamber, lubricates the seal face, and exits into
the pump itself. Positive flow in the seal water line
indicates adequate seal water pressure.

Cartridge Seals

Follow the appropriate lubrication directions for
mechanical seals given in this section. Most cartridge
seals provide flushing connections on their glands.
Use the cartridge seal gland flushing taps (if provided)
for your seal water connections instead of the stuffing
box tap. The quench taps on the glands (if present)
are normally only used in chemical applications.
Consult seal manufacturer’s literature for more
detailed information.

Cyclone Separator

If the fluid being pumped contains sediment and there
is no external, clean water source available to flush
the mechanical seals, a cyclone separator can be
used to remove most of the sediment from the liquid
being pumped so it can be used to flush the seals.
The separator is placed in the seal water piping line
and removes the sediment to an external drain
(normally back to the pump suction line).

3

22 3408 IOM 03/99