SAMCO CP7 User manual

SAMCO PUMPS
TYPE:CP7 Pumps
INSTRUCTIONS
Installation
Operation
Maintenance

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TABLE OF CONTENTS
PAGE PAGE
l. INTRODUCTION 3 VII. SERVICING 33
A. PURPOSE OF MANUAL 3 A. DISASSEMBLY 33
B. SAMCO / A-C PUMP – SERVICE 1.WET END 33
ORGANIZATION 3 2. FRAME DISASSEMBLY 34
C. WARRANTY 3 B. PART INSPECTION 35
C. ASSEMBLY 36
II. PUMP IDENTIFICATION (NAMEPLATE) 3 1. FRAME 36
2. WET END 37
III. SAFETY INFORMATION 4 D. ADJUSTMENTS 41
1. IMPELLER CLEARANCE 41
IV. INSTALLATION 4 2. SEALWATER 41
A. RECEIVING PUMP 4
B. STORAGE 5 APPENDIX “A”
1. TEMPORARY 5 ENGINEERING INFORMATION 43
2. LONG TERM 5 A. CASING & IMPELLER DATA
C. LOCATION 5 B. STUFF BOX DATA
D. FOUNDATION 5 SEAL LUBRICATION PRESSURE 45
E. SETTING BASEPLATE 6 C. SHAFT AND BEARING DATA 46
F. ALIGNMENTPROCEDURE 7 D. PUMP WEIGHTS 47
G. DOWELING 11
H. SUCTION AND DISCHARGE PIPING11 APPENDIX “D”
I. STUFFING BOX LUBRICATION 15 IMPELLER TRIMMING 47
V. OPERATION 19 ASSEMBLY SECTION (PACKING) 49
A. PRE-START CHECKS 19
B. PRIMING 19 ASSEMBLY SECTION
C. STARTING 20 (STD. STUFF. BOX, MECH. SEAL) 53
D. OPERATIONAL CHECKLIST 20
E. SHUTDOWN 21 ASSEMBLY SECTION (OVERSIZE
F. FREEZE PROTECTION 21 STUFF. BOX, MECH. SEAL) 55
G. FIELD TESTS 21
ASSEMBLY SECTION
VI. MAINTENANCE 23 (DYNAMIC SEAL F4-G1 FRAME) 58
A. GENERAL MAINTENANCE AND
PERIODIC INSPECTION 23 ASSEMBLY SECTION
B. MAINTENANCE OF FLOOD (DYNAMIC SEAL F4-H1 FRAME) 59
DAMAGED PUMPS 23
C. LUBRICATION 24 ASSEMBLY SECTION
1. BEARINGS 24 (DYNAMIC SEAL F4-J1 FRAME) 60
2. COUPLINGS 26
D. SEAL INFORMATION 26
1. PACKING 26
2. MECHANICAL SEALS 27
E. MAINTENANCE TIMETABLE 28
F. TROUBLE SHOOTING 28
NOTE
The information contained in this book is intended to assist operating personnel by providing information on the
characteristics of the purchased equipment.
It does not relieve the user of their responsibility of using accepted engineering practices in the installation,
operation, and maintenance of this equipment.
Any further questions, contact SAMCO / A-C Pump.

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SECTION I. INTRODUCTION
A. PURPOSE OF MANUAL:
This manual is furnished to acquaint you with the easiest and most practical way to install, operate, and
maintain this pump. Read it completely before doing any work on your unit and keep it handy for future
reference.
Equipment cannot operate well without proper care. To keep the unit at top efficiency, follow the recom-
mended installation and servicing procedures outlined in this manual. The S.A.M. Engineering (Pty) Ltd
Customer Service Department is available to expertly guide the installation of the pump for maximum
operating life and minimum downtime.
B. S.A.M. Engineering (Pty) Ltd Service organisation:
Experienced, factory trained servicemen offer prompt, efficient service at reasonable rates. These
servicemen can find and correct costly errors such as poor grouting, misalignment, pipe stresses
transmitted to the pump casing, or improperly sized piping. A serviceman may be requested through your
nearest S.A.M. Engineering Pump Sales Representative.
Replacement and spare parts, including special attention to your individual problems, may also be
obtained through the same Sales Representative.
C. WARRANTY:
Refer to your sales contract for coverages.
SECTION II. PUMP IDENTIFICATION (NAMEPLATE)
These pumps are designated by serial number, model, size, and M.O.C. This information is stamped on
an identification plate and affixed to the pump frame or casing.
Permanent records are kept by the factory and filed by serial number.
The pump nameplate contains the following information:
(1) SERIAL NUMBER –Composed of certain groups of numbers. All groups are necessary for
identification. TYPICAL EXAMPLE: P 2081 / 98
(2) MODEL – CP7, followed by SIZE – Composed of three (3) groups of number.
EXAMPLE: 4 x 3 x 11 – First number (4) is the ASA suction flange size in inches, second number
is the ASA discharge flange size in inches, the third number (11) is the nominal maximum impeller
diameter in inches.
(3) IMPELLER DIAMETER – This number is the impeller diameter in millimeters as supplied by the
factory. EXAMPLE: 265
(4) FLOW – design flow rate in cubic metres per hour.
(5) HEAD – design head in metres.
(6) MAX. DESIGN PRESSURE – This refers to factory standard hydrostatic test pressure for hydraulic
end of pump.
(7) M.O.C. – Material of construction of pump shown in abbreviated form and in four parts.
EXAMPLE: CI/SS/CI/EN8 – where casing, stuff box and wearplate (if fitted) are in Cast Iron /

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impeller in Stainless Steel / frame is in Cast Iron / shaft is in EN8
(8) RPM – Design speed of pump to achieve design flow and head.
SECTION III. SAFETY INFORMATION
WARNING: Unit weights are given on page 31. Failure to follow all instructions may result in serious
injury, death, or property damage.
Read all warning & caution decals on the pump.
Never use motor lifting lugs or pump casing lugs to lift entire unit.
When field hydro testing pump or system, do not exceed maximum field hydro test pressure given on
pump nameplate. Vent all air from pump and piping.
CAUTION: Pump damage will occur if rotation is reversed. Check rotation of driver with coupling
disconnected. Failure to follow these instructions could result in severe personal injury or property
damage.
WARNING: Do not operate at or near zero flow (closed shutoff valve). Explosion could result due to
large temperature rise in the fluid being pumped. Failure to follow these instructions could result in
property damage, severe personal injury, or death.
WARNING: If pump is to be used on process fluids above 49°C pump surface temperatures could be
warm enough to cause burns. We recommend pump surfaces be insulated. Failure to follow these instruc-
tions could result in severe personal injury or death.
SECTION IV. INSTALLATION
A. RECEIVING PUMP:
Check pumps 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 base plate. Couplings may either
be completely assembled or have the coupling hubs mounted on the shafts and the connecting members
unfastened.
Shafts are in alignment when the unit is shipped; however, due to shipping, the pumps may arrive mis-

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aligned and, therefore, alignment must be established during installation. S.A.M. Engineering (Pty) Ltd
has determined that proper and correct alignment can only be made by accepted erection practices. Refer
to the following paragraphs on "Foundation", "Setting Base plate", "Grouting Procedure", "Alignment
Procedure" and "Doweling".
B. STORAGE:
1. Short term (less than 6 months): S.A.M. Engineering normal packaging procedure is designed to
protect the pump during the shipping. Upon receipt, store in a covered and dry location.
2. Long term (more than 6 months): Preservative treatment of bearings and machined surfaces will
be required. Rotate shaft several times every 3 months. Refer to driver, coupling and seal
manufacturers for their long term storage procedures. Store in a covered dry place.
C. 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 (NPSH) at pump suction is provided. Available NPSH must always equal or
exceed the required NPSH of the pump.
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 shutdown
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 drive. If motor driven, electrical
characteristics should be identical to those shown on motor data plate.
D. FOUNDATION:
The foundation must be substantial enough to absorb vibration. (Hydraulic Institute Standards
recommend the foundation weight at least five (5) times the weight of the pump unit.) It must form a
permanent and rigid support for the base plate. This is important in maintaining the alignment of a
flexibly coupled unit.
Foundation bolts 6 mm smaller in diameter than the clearance holes in the base plate should be embedded
in the concrete to a depth of eight (8) times the diameter of the bolt 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 long 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.
The foundation should be poured within 20-40 mm of the finished height. (See Figure I) Freshly poured

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foundations should be allowed to cure for several days before the unit is set in place and grouted.
E. SETTING BASEPLATE:
Pump units are checked at the factory for alignability 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.
Initial or rough alignment must be done prior to grouting of base plate. Rough alignment is designated as
0.51 mm TIR parallel alignment and 0.23 mm TIR per 25.4mm of radius angular alignment (See
"Alignment Procedure" on page 4). Use blocks at anchor bolts and midway between to position bottom of
base at finished height (See Figure II) with foundation bolts extending through holes in the base plate.
Metal wedges with a small taper may be used in lieu of blocks and shims.
If the unit has a non-flexible coupling, the coupling halves should be disconnected; this is generally not

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necessary on flexible type couplings.
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.
If driver is being field installed, it should be centered in its bolt holes with shims added to bring the motor
into rough alignment with the pump.
NOTE: Do not exceed six (6) shims, using as thick a shim as possible, otherwise "sponginess" or "soft
foot" will result.
Level and plumb the pump shaft, coupling faces and flanges by adding or removing shims between the
blocks and 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 nonflexible coupling should not be reconnected until the
alignment operation has been completed.
NOTE: The base plate does not have to be level.
After foundation bolts are lightly torqued, recheck alignment requirements once more. Follow require-
ments outlined at the beginning of this section. Add or remove shims under the base and snug anchor
bolts until rough alignment tolerances are met.
Then the unit can be grouted in (See Figure II.)
Grout compensates for the uneven foundation. Together with the base plate, it makes a very rigid inter-
face between the pump and foundation distributing the weight over the length of the base and prevents
shifting.
Use an approved, non-shrinking grout.
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 base plate 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-based paint to the exposed edges of the grout to prevent air and moisture from
coming in contact with the grout.
F. ALIGNMENT PROCEDURE:
1. Standard couplings:
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:
a. Angular misalignment - shafts have axis concentric at intersection, but not parallel.

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b. Parallel misalignment - shafts have axis parallel, but offset.
The necessary tools for checking alignment are (1) a straight edge and caliper or micrometer, or (2) a dial
indicator with mounting magnet and extension bars.
Method 1 - Straight Edge
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 with micrometer or caliper at 90° intervals. The unit is in angular alignment
when these four (4) measurements are the same. (Figure IIIa.)
Check for parallel alignment by placing a straight edge across both the 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. (Figure IIIb.)

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Method 2: Dial Indicators
A dial indicator can be used to attain more accurate alignment. Fasten the indicator to the pump half of
the coupling and adjust the assembly until the indicator button is resting on the other half coupling
periphery.
The following steps are used to measure indicator assembly sag:

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Take indicator assembly as is and mount it on any short section of the pipe. Holding the pipe
horizontally with indicator assembly on top, set the dial to zero. Rotate the pipe 180° so the indicator
assembly is on the bottom and read the dial. This reading represents indicator assembly sag and must be
considered in the alignment readings.
Set the indicator back on the pump as before. Set the dial to zero and chalk mark the coupling half where
the button rest. (Chalk is 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. After
each adjustment, recheck both parallel and angular alignments. 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. For angular alignment, change the indicator so it bears against the face of the
same coupling half and proceed similarly to above. See Figure IVa & IVb.
NOTE: Gross deviation in squareness or concentricity may cause unbalance problems and if so must be
corrected.
NOTE: Permissible misalignment will vary with the type of coupling. Consult coupling manufacturer's
data.
Parallel: 0.4 mm TIR
Angular: 0.004 mm/25.4mm of Radius
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 runout. All measurements should be taken with the pump and
motor bolts tightened. The shaft of a sleeve bearing motor should be in the centre of its mechanical float.
2. MOUNTING C-FACE MOTORS
When mounting C-face motors in the field to pumps equipped with C-face motor adapters, the following
steps must be followed in the sequence given:
a. Slide coupling hubs on pump and motor shaft.
b. Be sure C-face adapter is bolted tight to frame and locating fit is clean.
c. Then mount C- face adapter support foot and tighten.

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d. Mount motor to C-face adapter again making sure locating fits are clean.
e. Attach support studs to motor feet as shown on following page.
f. Connect coupling and verify alignment is within 0.2mm TIR parallel.
g. Replace all guards.
After installing motor to "c" -face adapter, add supports as follows:
1. Put upper nut and washer on screw. (Fig. 1)
2. Place this assembly in motor foot and add lower nut and washer.
3. Be sure the screw touches the base, then tighten lower nut and washer until it is firm against
bottom of motor foot. (Fig. 2) Caution! Do not lift motor. Screws are for support only.
4. Now lower top nut and washer against top of motor foot. These are for locking the assembly in
place. (Fig. 3)
5. Some combinations require the screw be mounted upside down rather than as shown.
G. DOWELING
Pump units may, if desired, (or required in specification) be dowelled on diagonally opposite feet. This
should not be done until the unit has been run for a sufficient length of time and alignment is within the
TIR tolerance previously stated.
H. SUCTION AND DISCHARGE PIPING:
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. Suction and discharge piping should be
anchored, supported and restrained near the pump to avoid strain on the pump. When using rubber
expansion joint, follow the recommendations of the manufacturer.
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.
When installing the pump piping, be sure to observe the following precautions:
1. Piping should always be run to the pump.
2. Do not move pump to pipe. This could make final alignment impossible.

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3. 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 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 strain on the pump resulting from
system pressure changes. It’s usually advisable to increase the size of both suction and discharge
pipes at the pump connections to decrease the loss of head from friction.
4. Install piping as straight as possible, avoiding unnecessary bends. Where necessary, use 45° or long
sweep 90° fitting to decrease friction losses.
5. Make sure that all piping joints are airtight.
6. Where flanged joints are used, assure that inside diameters match properly.
7. Remove burrs and sharp edges when making up joints.
8. Do not "spring" piping when making any corrections.
9. Provide for pipe expansion when hot fluids are to be pumped.
Suction piping:
When installing the suction piping, observe the following precautions (See Figure V.)
The sizing and installation of the suction piping is extremely important. It must be selected or 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.
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 (distance A) between any elbow or tee and
the pump is required. If a long suction pipe is required, it should be one or two sizes larger than the
suction opening, depending on its length.
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 will become filled with air
and thus 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.
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.
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".)
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.

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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.
Inlet bells, pipe size, and wet well (sump) dimensions should conform to the recommendations of the Hy-
draulic Institute Standards latest edition.
Discharge piping:
If the discharge piping is short, the pipe diameter can be the same as the discharge opening. If the piping
is long, 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 gate valve should be installed in the discharge. The check valve, placed between pump
and gate valve, protects the pump from excessive backpressure, and prevents liquid from running back
through the pump in case of power failure. The gate valve is used in priming and when shutting the pump
down.

14

15
Pressure gauges:
Properly sized pressure gauges should be installed in both the suction and discharge nozzles in the gauge
taps, which are 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 cavitations,
vapor binding, or other unstable operation should occur, widely fluctuating discharge pressure will be
noted.
I. STUFFING BOX LUBRICATION:
NOTE: CP7 Plus pumps can be furnished with a standard stuff box or oversize seal chamber.
Oversize seal chambers are available as either cylindrical bore or tapered bore designs. Consider
using oversize seal chamber or Dynamic Seal on difficult sealing applications. Standard stuffing box
can be furnished with a mechanical seal or packing arrangement. Both standard and oversize stuffing
boxes are available as an option with internal flushing. Standard and oversize stuffing boxes
accommodate all types of mechanical seals and gland arrangements. Water cooling or steam jackets
are also available as an option on standard stuff boxes only.
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 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 slightly above the maximum stuffing box pressure.
If the pump system pressure conditions vary during the day, packing adjustment becomes difficult.
Consideration should be given to using a mechanical seal. (See "Mechanical Seals".)
Stuffing box operating pressure:
On pumps supplied with packing, the actual stuffing box operating pressure may be obtained by installing
a pressure gauge on the box. This is done with extra lantern rings temporarily replacing the three rings of
packing in the bottom of the box to obtain accurate gauge readings. Take gauge readings with the pump
running under various head and capacity conditions. Then set the pressure of flushing or lubrication liquid
at a value 1.4 bar above the maximum expected stuffing box operating pressure.
Even under the best conditions, a properly packed stuffing box should be watched closely. If pressure
conditions change slightly, there will be a resultant change in packing "seating" which should be com-
pensated by a change in gland adjustment. Consideration should also be given to the lubrication pressure.
A wide variation indicates a need to use a mechanical seal.
Packing:
Standard pumps are not packed before shipment.
NOTE: Packing adjustment is covered under Section VI, "Maintenance".
Lubricate packing with pumped fluid only when all the following criteria are met:
1. Liquid is clean, free from sediment and chemical precipitation and is compatible with seal
materials.
2. Temperature is above 0° C and below 70° C. Suction pressure is below 5 bar g.

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3. Suction pressure is below 5 bar g.
4. 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 the following conditions prevail:
1. Liquid being pumped contains dirt, grit, or other impurities.
2. Temperature of pumped liquid is below 0° C or above 70° C.
3. Liquid being pumped has non-lubrication properties.
4. Liquid is toxic or volatile.
5. Suction pressure is above 5 bar g, vacuum, or high lift.
The standard stuffing box consists of rings of packing (see assembly section for number of rings), a
lantern ring, and a gland. A shaft sleeve, which extends through the box and under the gland is normally
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 1 l / min at the proper pressure.
One recommended method to minimize error in regulating flushing water is a "Controlled Pressure Sys-
tem" (Figure VI). Most important is the pressure-reducing valve adjusted to a value slightly exceeding the
maximum stuffing box operating pressure (assuming it’s reasonably constant). A flow-indicating device
will serve to indicate a failing of the bottom packing rings allowing leakage into 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 (40-60 drops per minute). Excess pressure from an external source
can be very destructive to packing.

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More pressure is required, however, for 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.
Mechanical seals:
Mechanical seals are preferred over packing on most 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 (Standard stuffing box only). Conversion parts
may be ordered from your S.A.M. Engineering outlet.
A mechanical seal consists of a rotating element and a stationary element. The sealing faces are highly
lapped surfaces. The faces run with a very thin film of liquid between them. Since mechanical seals are
made with a wide, variety of designs, the instructions for the specific seal must be carefully studied and
followed. A mechanical seal is a precision device and must be treated accordingly. When the pump is
equipped with a mechanical seal, no attention or adjustment to the seal is normally required. Except for
possible slight initial leakage, the seal should operate with negligible leakage.
Just as with packing, the mechanical seal chamber must be supplied 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, contaminants may
enter the stuffing box. If the pressure is too high, excessive seal wear may result. Difficult seal applica-
tions may require the use of various API seal flush piping plans.
Double mechanical seals:
A double mechanical seal consists of two single seals mounted back-to-back and a suitable sealing liquid
which is introduced into the seal chamber. The sealing liquid (preferably clear water) is injected through
the tap in the gland into the box at a higher pressure than that which exists at the entrance to the seal
cavity on the pump side. The pressure differential isolates the sealing faces from the pumped liquid.
Double mechanical seals are normally preferred in pumps handling slurries, or any other solids suspended
in the pumped liquid, or when product dilution by the seal water is a problem.
The sealing liquid pressure must always be higher than the pressure on the seal closer to the suction side
(inside seal). If sufficient sealing pressure is not maintained, the pressure within the pump can force open
the inside seal and allow the pumped liquid to enter the box, which can damage the seals.
A recommended "Controlled Pressure System" for a double mechanical seal is shown in Figure VII.

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Flow rate through the seal chamber should be approximately 1 l /min. The correct pressure is most impor-
tant. The purpose of the manual valve in the exit line is to create the necessary backpressure so that
proper stuffing box pressure can be maintained. It is important that the exit line be attached at the top of
the stuffing box so air is vented out.
Single mechanical seals:
Single mechanical seals are normally used when the pumped fluid is suitable to lubricate the mechanical
seal. When pumped fluid is suitable to lubricate the mechanical seal recirculation from pump discharge to
the flush tap on the gland through the standard by-pass line can be used. Internal recirculation from a high
pressure point is also available as an option. Single seals can also be used when contaminants are present
in the pumpage if a throttle bushing is supplied at the bottom of the stuffing box. The bushing acts to limit
product dilution.
When contaminants are present in the pumpage, an external source of clean seal water must be supplied.
Figure VIII shows the recommended "Controlled Pressure System" for a single mechanical seal with a
throttle bushing. Seal water enters the seal chamber, lubricates the seal faces, and exits under the throttle
bushing into the pump itself. Positive flow in the seal water line indicates adequate seal water pressure.

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Cartridge seals:
Follow the appropriate lubrications directions (single seal or double seal) given in this section. Use the
cartridge seal gland flushing taps for your seal water connections. Most cartridge seals provide flushing
connections on their glands. The quench taps on the glands (if present) can be used when necessary. Con-
sult seal manufacturer's literature for more detailed information.
SECTION V. OPERATION
A. PRE-START CHECKS:
Before initial start of the pump, make the following inspections:
1. Check alignment between the pump and motor. See Section IV, F, for alignment requirements.
2. Check all connections to motor and starting device with wiring diagram. Check voltage, phase, and
frequency on motor nameplate with line circuit.
3. Check suction and discharge piping and pressure gauges for proper operation.
4. Check impeller adjustment, see Section VII, D for proper adjustment.
5. Turn shaft by hand to assure that it rotates freely.
6. Check stuffing box adjustment, lubrication and piping.
7. Check driver lubrication.
8. Assure that pump bearings are properly lubricated.
9. Assure that coupling is properly lubricated, if required.
10. Assure that pump is full of liquid (see Section V, B) and all valves are properly set and opera-
tional, with the suction valve open. Purge all air from top of casing.
11. Check rotation with coupling disconnected. Be sure that the driver operates in the direction
indicated by the arrow on the pump casing as serious damage can result if the pump is operated
with incorrect rotation. Check rotation each time the motor leads have been disconnected.
B. PRIMING:
If the pump is installed with a positive head on the suction, it can be primed by opening the suction and
vent valve and allowing the liquid to enter the casing.
If the pump is installed with a suction lift, priming must be done by other methods such as foot valves,
ejectors, or by manually filling the casing and suction line.
NOTE: under either condition the pump must be completely filled with liquid before starting. The pump
must not run dry in the hope it will prime itself.
Flushing:
New and old system should be flushed to eliminate all foreign matter. Heavy scale, welding splatter and
wire or other large foreign matter can clog the pump impeller. This will reduce the capacity of the pump
causing cavitation or excessive vibration.

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Filling:
Vents should be located at the highest point so entrained gases and air can escape. However, if the gases
are flammable, toxic, or corrosive they should be vented to an appropriate place to prevent harm to
personnel or other parts of the system. Pipe hangers and anchors should be checked to make sure they are
properly set to take the additional weight of the pumpage.
All drains should be closed when filling the system. Filling should be done slowly so that excessive
velocities do not cause rotation of the pumping elements, which may cause damage to the pump or its
driver. The adequacy of the anchors and hangers may be checked by mounting a dial indicator off of any
rigid structure not tied to the piping and setting the indicator button on the pump flange in the axial
direction of the nozzle. If the indicator moves, as the filling proceeds, the anchors and supports are not
adequate or set properly and should be corrected.
C. STARTING:
1. Close drain valves.
2. Open fully all valves in the suction. Discharge valve can be fully open if a check valve is installed.
3. Turn on seal water to the stuffing box. (If pumped fluid is dirty, these lines should always be left
open except when using double mechanical seals.)
4. Prime the pump.
NOTE: If the pump does not prime properly, or loses prime during start-up, it should be shut down and
the condition corrected before the procedure is repeated.
5. Start the pump drive (turbines and engines may require warming up; consult the manufacturer's
instructions).
6. When the pump is operating at full speed, check to see that the check valve has opened up. Check
valve must open 5 seconds or less after start-up to prevent damage to pump by operating at zero
flow.
7. Adjust the seal water valves to produce the recommended pressure for either the mechanical seal or
packed stuffing box.
D. OPERATIONAL CHECKLIST:
1. Driver/Pump Rotation:
Check rotation each time the motor leads have been disconnected. Be sure that the driver operates
in the direction indicated by the arrow on the pump casing. Serious mechanical damage can result
if the pump is operated in the wrong direction.
2. Coupling:
Recheck coupling alignment per Section IV, F.
3. Stuffing Box Adjustment:
Make stuffing box packing gland and lubrication adjustment per Section VI, D.
4. Flow:
An accurate measurement of flow rate (volume/time) is difficult in the field. Venturi meters, flow
nozzles, orifice plates, or timing the draw down in the sump are all possible methods. Record any
reading for future reference.
5. Pressure: