Pentair Myers Aplex MA-155L Manual

NOTE! To the installer: Please make sure you provide this manual to the owner of the equipment or to the responsible
party who maintains the system.
MODELS
MA-155L, MA-155M, MA-155M-HD, SC-230
TRIPLEX PUMPS
INSTALLATION AND SERVICE MANUAL
Part # AP-03-105 | © 2018 Pentair plc. | 04/12/18

2 3
Engineering Data
MA-155L ................................................................... 3
MA-155M .................................................................. 4
MA-155M-HD ........................................................... 5
SC-230...................................................................... 6
Dimensional Data.................................................. 7–8
Installation, Operation, Lubrication, Maintenance
and Storage Instructions ..........................................9
Safety........................................................................ 9
Storage ..................................................................... 9
Pump Location and Piping Design........................... 9
Suction Piping .....................................................9–10
Acceleration Head...................................................10
Discharge Piping ...............................................10–11
Bypass Piping..........................................................11
Lubrication ..............................................................11
V-Belt Drive.......................................................11, 13
Suggested Piping System for Plunger Pumps .......12
Direction of Rotation ...............................................13
Automatic (Safety) Shutdowns................................13
Crankshaft Assembly.............................................. 13
General....................................................................13
Tapered Roller Bearings .........................................13
Cup Installation ................................................. 13-14
Installing Crankshaft ..............................................14
Shim Adjustment of Tapered Roller Bearings........14
Installation of Crankshaft Oil Seal..........................14
Disassembly ............................................................14
Connecting Rod, Crosshead, Extension Rod, Cross-
head Pin and Wiper Box Assembly/Disassembly ....14
General.............................................................. 14-15
Installing Wrist Pin Bushings .................................15
Bolting the Wrist Pin...............................................15
Order of Assembly.............................................15–16
Oil Scoop..................................................................16
Wiper Box Assembly............................................... 16
General....................................................................16
Poly Pak®Seal.........................................................16
Mechanical Oil Seal.................................................16
Double-Lip Wiper Seal............................................16
Double-Lip Canned Wiper.......................................16
Inserting the Extension Rod.............................. 16-17
Stuffing Box, Packing and Plunger Assemblies ......17
General....................................................................17
Spring Loaded Packing............................................17
J-Style Stuffing Box & Plunger Assembly
(Styles 838 and 858) ...............................................17
Inserting the Plunger..............................................18
Installing the Gland.................................................18
Installing the Stuffing Box.......................................18
Connecting the Plunger ..........................................18
Packing....................................................................18
Plungers............................................................ 18-19
Disc Valve Systems and Abrasion Resistant
Valve Construction.................................................. 19
General....................................................................19
Disc Valve and Abrasion Resistant
Valve Construction ..................................................19
Setting the Valve Seat..............................................19
Installing O-Rings, Abrasion Resistant Spring
and Cage..................................................................19
Installing Disc, Spring, Disc Valves and Stem ........19
Valve Spring Options ...............................................20
Valve Disc Options ...................................................20
Pulling the Valve Seat..............................................20
Salvage of Worn Seats.............................................20
Other Pump Brands ................................................20
Trouble Location and Remedy........................... 21–23
Parts Lists ........................................................ 24–29
Warranty................................................................30

3
MA-155L ENGINEERING DATA
Power End
Model Triplex Pump MA-155L
Maximum Input HP at Speed 155 at 450 rpm
Rated Continuous Plunger Load 9,087 lbs.
Stroke 4-1/2"
Maximum Rated Continuous Speed 450 rpm
Normal Continuous Speed Range 150 to 420 rpm
Minimum Speed 100 rpm
Oil Capacity 22 U.S. Quarts
Viscosity, S.S.U. at 210º F 70 to 84
Power End Oiling System Splash
Power Frame, One Piece Cast Iron
Crosshead, Full Cylindrical Cast Iron
Crosshead, Diameter x Length 5-3/4" x 6-3/16"
Crankshaft Ductile Iron
Crankshaft Diameters:
At Drive Extension
At Tapered Roller Bearings
At Crankpin Bearings, Diameter x Length
4.500/4.499"
4-3/4"
4-1/2" x 3-3/4"
Crosshead (Wrist) Pin, Case-Hardened and Ground AISI 8620
Wrist Pin Bushing, SAE 660, Diameter x Width 2-5/8" x 3-5/8"
Main Bearings, Tapered Roller Timken
Crankpin Bearings,
Precision Automotive
Steel Backed, Babbitt-
Lined
Extension (Pony) Rod:
Diameter
Material
2-1/2"
17-4PH S.ST.
Connecting Rod, Rifle Drilled Ductile Iron
Average Crosshead Speed:
At 450 rpm 338 fpm
Minimum Life Expectancy, Main Bearings, L10 60,000+hr
Liquid End
Plunger Size Range, Diameter 2-3/4" Thru 4"
Maximum Continuous Working Pressure 1,389 psi
Hydrostatic Test:
Discharge 2,175 psi
Suction Connection Size 6" ANSI
Hydrostatic Test, Suction 425 psi
Available Liquid End Materials, ASTM:
Nickel Aluminum Bronze
Forged Steel Block
B148-C955
A105
MA-155L ENGINEERING DATA
Liquid End (Continued)
Plunger Type Rokide®Stainless Steel:
Chromium Oxide-Coated 316 S.ST.
Stuffing Boxes, Field-Removable and Replaceable:
Aluminum Bronze
Carbon Steel
B148-C955
1020
Packing Types Available:
Gland-loaded, Nonadjustable
Spring-loaded, Cup-Type
Spring-loaded, Braided PTFE Coating & Aramid Fiber
Spring-loaded, Garlock
Style 838
Style 120X
Style 140/141
Style 8921K
Studs, Material,
ASTM
A193 Grade B7,
Cadmium Plated
Nuts, Material, ASTM A194 Grade 2
Seals, Stuffing Boxes, Valve Covers, Cylinder Heads Buna-N
Bolting, High Strength, Heat Treated Alloy Steel
Available Valve Types:
Standard, Acetal Resin
Optional, Hardened and Lapped
Double Stem-Guided
Acetal
17-4PH S.ST.
17-4PH S.ST.
Valve Seat, Liquid Passage Areas
Plate (Disc) Valves, (Acetal or S.ST.) 6.54 sq. in.
Average Liquid Velocity, 4" Plungers at 450 rpm:
Thru Seat
Suction Manifold
Discharge Manifold
10.8 fps
3.7 fps
16.1 fps
General
Overall Dimensions:
Length
Width
Height
55-3/4"
43"
22"
Approximate Weights:
With Aluminum Bronze Liquid End
With Forged Steel Liquid End
2,680 lbs.
2,900 lbs.

4 5
MA-155M ENGINEERING DATA
Power End
Model Triplex Pump MA-155M
Maximum Input HP at Speed 155 at 450 rpm
Rated Continuous Plunger Load 9,087 lbs.
Stroke 4-1/2"
Maximum Rated Continuous Speed 450 rpm
Normal Continuous Speed Range 150 to 420 rpm
Minimum Speed 100 rpm
Oil Capacity 22 U.S. Quarts
Viscosity, S.S.U. at 210ºF 70 to 84
Power End Oiling System Splash
Power Frame, One Piece Cast Iron
Crosshead, Full Cylindrical Cast Iron
Crosshead, Diameter x Length 5-3/4" x 6-3/16"
Crankshaft Ductile Iron
Crankshaft Diameters:
At Drive Extension
At Tapered Roller Bearings
At Crankpin Bearings, Diameter x Length
4.500/4.499"
4-3/4"
4-1/2" x 3-3/4"
Crosshead (Wrist) Pin, Case-Hardened and Ground AISI 8620
Wrist Pin Bushing, SAE 660, Diameter x Width 2-5/8" x 3-5/8"
Main Bearings, Tapered Roller Timken
Crankpin Bearings,
Precision Automotive
Steel Backed, Babbitt-
Lined
Extension (Pony) Rod:
Diameter
Material
2-1/2"
17-4PH S.ST.
Connecting Rod, Automotive Type Ductile Iron
Average Crosshead Speed:
At 450 rpm 338 fpm
Minimum Life Expectancy, Main Bearings, L10 60,000+hr
Liquid End
Plunger Size Range, Diameter 1-3/4" Thru 2-3/4"
Maximum Continuous Working Pressure 3,430 psi
Hydrostatic Test:
Discharge 5,400 psi
Discharge Connection Size 6" ANSI 1500
Suction Connection Size 8" ANSI 150
Hydrostatic Test, Suction 425 psi
Available Liquid End Materials, ASTM:
Nickel Aluminum Bronze
Forged Steel Block
B148-C955
A105
MA-155M ENGINEERING DATA
Liquid End (Continued)
Plunger Type Rokide®Stainless Steel:
Chromium Oxide-Coated 316 S.ST.
Stuffing Boxes, Field-Removable and Replaceable:
Aluminum Bronze
Carbon Steel
B148-C955
1020
Packing Types Available:
Gland-loaded, Nonadjustable
Spring-loaded, Cup-Type
Spring-loaded, Braided PTFE Coating & Aramid Fiber
Spring-loaded, Garlock
Style 838
Style 120X
Style 140/141
Style 8921K
Studs, Material,
ASTM
A193 Grade B7,
Cadmium Plated
Nuts, Material, ASTM A194 Grade 2
Valve Cover and
Cylinder Head Plugs
416 S.ST. or
316 S.ST.
Seals, Stuffing Boxes, Valve Covers Buna-N
Bolting, High Strength, Heat Treated Alloy Steel
Available Disc Valve Types:
Standard, Acetal Resin
Optional, Hardened and Lapped
Acetal
17-4PH S.ST.
Valve Set, Material, Hardened and Lapped 17-4PH S.ST.
Valve Seat, Liquid Passage Areas:
Plate (Disc) Valves, (Acetal or S.ST.) 3.9 sq. in.
Average Liquid Velocity, with 2-3/4" Plungers
at 450 rpm:
Thru Seat
Suction Manifold
Discharge Manifold
8.5 fps
3.9 fps
16.9 fps
General
Overall Dimensions:
Length
Width
Height
54-3/16"
43"
22"
Approximate Weights:
With Aluminum Bronze Liquid End
With Forged Steel Liquid End
2,500 lbs.
2,700 lbs.

5
MA-155M-HD ENGINEERING DATA
Power End
Model Triplex Pump MA-155M-HD
Maximum Input HP at Speed 175 at 450 rpm
Rated Continuous Plunger Load 10,259 lbs.
Stroke 4-1/2"
Maximum Rated Continuous Speed 450 rpm
Normal Continuous Speed Range 150 to 420 rpm
Minimum Speed 100 rpm
Oil Capacity 22 U.S. Quarts
Viscosity, S.S.U. at 210ºF 70 to 84
Power End Oiling System Splash
Power Frame, One Piece Cast Iron
Crosshead, Full Cylindrical Cast Iron
Crosshead, Diameter x Length 5-3/4" x 6-3/16"
Crankshaft Forged and
Nitrided Alloy Steel
Crankshaft Diameters:
At Drive Extension
At Tapered Roller Bearings
At Crankpin Bearings, Diameter x Length
4.500/4.499"
4-3/4"
4-1/2" x 3-3/4"
Crosshead (Wrist) Pin, Case-Hardened and Ground AISI 8620
Wrist Pin Bushing, SAE 660, Diameter x Width 2-5/8" x 3-5/8"
Main Bearings, Tapered Roller Timken
Crankpin Bearings,
Precision Automotive
Steel Backed, Babbitt-
Lined
Extension (Pony) Rod:
Diameter
Material
2-1/2"
17-4PH S.ST.
Connecting Rod, Automotive Type Ductile Iron
Average Crosshead Speed:
At 450 rpm 338 fpm
Minimum Life Expectancy, Main Bearings, L10 50,000+hr
Liquid End
Plunger Size Range, Diameter 1-3/4" Thru 2-3/4"
Maximum Continuous Working Pressure 3,430 psi
Hydrostatic Test:
Discharge 5,400 psi
Discharge Connection Size 6" ANSI 1500
Suction Connection Size 8" ANSI 150
Hydrostatic Test, Suction 425 psi
Available Liquid End Materials, ASTM:
Nickel Aluminum Bronze
Forged Steel Block
B148-C955
A105
MA-155M-HD ENGINEERING DATA
Liquid End (Continued)
Plunger Type Rokide®Stainless Steel:
Chromium Oxide-Coated 316 S.ST.
Stuffing Boxes, Field-Removable and Replaceable:
Aluminum Bronze
Carbon Steel
B148-C955
1020
Packing Types Available:
Gland-loaded, Nonadjustable
Spring-loaded, Cup-Type
Spring-loaded, Braided PTFE Coating & Aramid Fiber
Spring-loaded, Garlock
Style 838
Style 120X
Style 140/141
Style 8921K
Studs, Material,
ASTM
A193 Grade B7,
Cadmium Plated
Nuts, Material, ASTM A194 Grade 2
Valve Cover and
Cylinder Head Plugs
416 S.ST. or
316 S.ST.
Seals, Stuffing Boxes, Valve Covers Buna-N
Bolting, High Strength, Heat Treated Alloy Steel
Available Disc Valve Types:
Standard, Acetal Resin
Optional, Hardened and Lapped
Acetal
17-4PH S.ST.
Valve Set, Material, Hardened and Lapped 17-4PH S.ST.
Valve Seat, Liquid Passage Areas:
Plate (Disc) Valves, (Acetal or S.ST.) 3.9 sq. in.
Average Liquid Velocity, with 2-3/4" Plungers
at 450 rpm:
Thru Seat
Suction Manifold
Discharge Manifold
8.5 fps
3.9 fps
16.9 fps
General
Overall Dimensions:
Length
Width
Height
54-3/16"
43"
22"
Approximate Weights:
With Aluminum Bronze Liquid End
With Forged Steel Liquid End
2,500 lbs.
2,700 lbs.

6 7
SC-230 ENGINEERING DATA
Power End
Model Triplex Pump SC-230
Maximum Input HP at Speed 310 at 450 rpm
Rated Continuous Plunger Load 18,320 lbs.
Stroke 4-1/2"
Maximum Rated Continuous Speed 450 rpm
Normal Continuous Speed Range 150 to 420 rpm
Minimum Speed 100 rpm
Oil Capacity 22 U.S. Quarts
Viscosity, S.S.U. at 210ºF 70 to 84
Power End
Oiling System
Pressure
Lubrication System
Power Frame, One Piece Cast Iron
Crosshead, Full Cylindrical Cast Iron
Crosshead, Diameter x Length 5-3/4" x 6-3/16"
Crankshaft Ductile Iron
Crankshaft Diameters:
At Drive Extension
At Tapered Roller Bearings
At Center Bearings
At Crankpin Bearings, Diameter x Length
4.500/4.499"
4-3/4"
9-3/8"
4-1/2" x 3-3/4"
Crosshead (Wrist) Pin, Case-Hardened and Ground AISI 8620
Wrist Pin Bushing, SAE 660, Diameter x Width 2-5/8" x 3-5/8"
Main Bearings, Tapered Roller Timken
Crankpin Bearings,
Precision Automotive
Steel Backed, Babbitt-
Lined
Extension (Pony) Rod:
Diameter
Material
2-1/2"
17-4PH S.ST.
Connecting Rod, Automotive Type Ductile Iron
Average Crosshead Speed:
At 450 rpm 338 fpm
Minimum Life Expectancy, Main Bearings, L10 20,000+hr
Liquid End
Plunger Size Range, Diameter 3-1/4" Thru 4"
Maximum Continuous Working Pressure 2,208 psi
Hydrostatic Test:
Discharge 3,300 psi
Suction Connection Size 6" NPT
Hydrostatic Test, Suction 425 psi
SC-230 ENGINEERING DATA
Liquid End (Continued)
Available Liquid End Materials, ASTM:
Steel A105
Piston Type Rubber
Liners Hardened Steel
Plunger Type Rokide®Stainless Steel:
Chromium Oxide-Coated 410 S.ST.
Stuffing Boxes, Field-Removable and Replaceable:
Aluminum Bronze
Carbon Steel
B148-C955
1020
Packing Types Available:
Gland-loaded, Nonadjustable
Spring-loaded, Cup-Type
Spring-loaded, Braided PTFE Coating & Aramid Fiber
Spring-loaded, Garlock
Style 838
Style 120X
Style 140/141
Style 8921K
Seals, Stuffing Boxes, Valve Covers, Cylinder Heads Buna-N
Bolting, High Strength, Heat Treated Alloy Steel
Available Valve Types:
Abrasion Resistant 17-4PH S.ST.
Valve Spring Material Inconel
Average Liquid Velocity, 4-1/2" Plungers at 450 rpm:
Suction Manifold
Discharge Manifold
3.7 fps
16.1 fps
General
Overall Dimensions:
Length
Width
Height
54-1/2"
43"
22"
Approximate Weights:
With Forged Steel Liquid End 2,900 lbs.

7
CROSS-SECTION
Ref. No. MA-155L MA-155M MA-155M-HD SC-230
A1 43 43 43 43
B1 54-1/2 53-7/8 53-7/8 –
B2 – 41-11/16 41-11/16 –
B3 20-13/16 19-3/4 19-3/4 –
B4 11 11 11 –
B5 10 9-1/8 9-1/8 –
B6 5-1/2 6-1/2 6-1/2 –
(B) Discharge Connections 3" ANSI 600 FF 2" ANSI 1500 FF 2" ANSI 1500 FF –
(B) Suction Connections 6" ANSI 150 FF 4" ANSI 150 FF 4" ANSI 150 FF –
C1 – 53-15/16 53-15/16 55-1/2
C2 – 41-3/4 41-3/4 –
C3 – 20-7/8 20-7/8 21-1/4
C4 11 11 11 11
C5 10 9-7/8 9-7/8 15
C6 5-1/2 5-1/8 5-1/8 –
(C) Discharge Connections 3" ANSI 600 RF 2" ANSI 1500 RF 2" ANSI 1500 RF 3" NPTF
(C) Suction Connections 6" ANSI 150 RF 4" ANSI 150 RF 4" ANSI 150 RF 6" NPTF
DIMENSIONAL DATA TABLE

8 9
SUCTION CONNECTION
C6
C5
C1
C2
C3
C4
DISCHARGE CONNECTION
SUCTION CONNECTION
B6
B5
DISCHARGE CONNECTION
B3
B4
B1
B2
5-3/4 TYP.
2 TYP.
4 TYP.
25
12-1/2
2-3/8
32-1/4
2-7/8
2
PUMP
CRANKSHAFT
PUMP
A1
DIMENSIONAL DRAWINGS
SUCTION CONNECTION
C6
C5
C1
C2
C3
C4
DISCHARGE CONNECTION
SUCTION CONNECTION
B6
B5
DISCHARGE CONNECTION
B3
B4
B1
B2
5-3/4 TYP.
2 TYP.
4 TYP.
25
12-1/2
2-3/8
32-1/4
2-7/8
2
PUMP
CRANKSHAFT
PUMP
A1
Cast Fluid End
SUCTION CONNECTION
C6
C5
C1
C2
C3
C4
DISCHARGE CONNECTION
SUCTION CONNECTION
B6
B5
DISCHARGE CONNECTION
B3
B4
B1
B2
5-3/4 TYP.
2 TYP.
4 TYP.
25
12-1/2
2-3/8
32-1/4
2-7/8
2
PUMP
CRANKSHAFT
PUMP
A1
Block Fluid End

9
INSTALLATION, OPERATION,
LUBRICATION, MAINTENANCE
AND STORAGE INSTRUCTIONS
SAFETY
Electrical power or engine must be shut off completely
before attempting service on the pump or its drive. Air
surrounding the unit to be free of toxic, flammable or
explosivegases.
Tools needed should be planned for in advance (see
valve seat pulling instructions), and should be clean
and of adequate size. A torque-wrench will be required
to tighten connecting rod capscrews.
A properly sized and set relief valve installed in the
pump discharge system (ahead of any block valves) is
necessary to protect personnel and to avoid dangerous
overpressure. The relief valve set pressure should
be not more than 25% above the design operating
pressure and should discharge to tank or to the
atmosphere (toward the ground), and must not be
directed back to the pump suctionsystem.
WARNING: Improper use of this equipment could
result in loss oflife.
CALIFORNIA PROPOSITION 65 WARNING:
WARNING: This product and related accessories
contain chemicals known to the State of California to
cause cancer, birth defects or other reproductiveharm.
STORAGE
Pumps are shipped dry from the factory. If a pump has
been in storage in a humid environment for more than
six months the crankcase cover should be removed
and carefully examined for rust or water collected
in the power end. Flush out any evidence of rust or
damage that exists, using a light cleanoil.
Pumps to be placed in extended storage should be
cleaned, repaired as needed and completely filled to
the top with clean oil to prevent rusting. Rotate pump
monthly 4-1/2 revolutions. Plug all openings to prevent
air entry and oilleakage.
Fluid ends must be completely drained of water and
suction and discharge ports blanked off. Store pump in
a clean, drylocation.
PUMP LOCATION AND PIPING DESIGN
Locate pump and driver in a clean, well drained,
ventilated and brightly illuminated area, with adequate
working spaces around the pump to provide ample
access to fluid end, power end and associated drive
elements. Do not expect good maintenance to result if
the pump is positioned on muddy terrain, or in a dirty,
cramped, dimly lightedarea!
The supply tank(s) should be large to allow dissolved
air and other gases to escape from the liquid and allow
suspended solids to settle out before entering pump.
A system employing dams and settling chambers
isdesirable.
CAUTION: All pumps should be installed level. For
mobile applications the maximum angle of intermittent
operation pumps (SC pumps) should be no more than
5degrees in any one direction.
Pumps are not designed to withstand piping weight,
vibration and the effects of thermal piping expansion/
contraction. Piping loads may be considerable and the
weight of all valving, dampeners, filters and associated
forces, moments and couples must be completely
isolated. Use flexible hoses and rigid piping supports
to isolate the pump and its driver from these effects.
SUCTION PIPING
No part of the piping system deserves more careful
planning than the suction piping system. Suction
piping must be short, direct and oversize. Use one pipe
size larger than the pump suction connection. The
shorter it is, the better! One to three feet per second
suction velocity is acceptable.
Reference the following table to size a direct suction
line from a tank to a pump.
Suction Piping
4" – 6" 6" – 8"
MA-155M MA-155-L
MA-155M-HD SC-230
Use no elbows, tees or restricted port valves in
this line. Do not install orifice plates or positive
displacement type fluid meters in the suction line
which act as flow restrictors. Avoid the use of suction
filters, if possible. Consider filtering the liquid as
it enters the supply tank rather than as it leaves
it. The use of an eccentric reducer with the flat
side up located at the pump suction connection is
recommended. The suction line should slightly rise
from tank to pump, and loops in which air may collect
must be avoided.
The absolute pressure in a suction line may be less
than atmospheric pressure and air may be “sucked”
into the line unless all flanges and connections are
airtight and watertight. If you can see water leaking
out of a suction line when the pump is still, that may
mean air is being sucked in when the pump is running.

10 11
Suction piping should be buried beneath the frost
line or insulated to avoid freezing in the winter. If the
suction line has a block valve at the supply tank, a
suitable relief valve is suggested to relieve the suction
piping from any possible dangerous overpressure from
the discharge pipingsystem.
Suction piping is often large, heavy (especially when
filled with liquid) and tends to vibrate. Proper solid
supports are recommended. A suction hose located
near the pump will isolate these effects, protecting
the pump from the forces and moments that piping
weightcreates.
New suction piping systems should be flushed free
of pipe scale, welding slag and dirt before starting
the pump. Hydrostatic testing to detect air leaks is
advisable. Proper choice of suction hose construction
is essential to avoid collapse of the hoseliner.
Install a dry type compound gauge in the suction
line near the pumps which should fluctuate evenly.
If violently pulsating, this gauge indicates that the
pump is not fully primed, or that one or more valves
areinoperative.
ACCELERATION HEAD
A characteristic of all reciprocating pumps is the
imperative need to consider the effects of acceleration
head which is a system-related phenomenon.
Acceleration head may be considered to be the loss of
available hydraulic head (energy) in the piping system
occurring because the demand by the pump cylinders
for liquid is not smooth and even. Because the pump’s
demand for liquid is cyclical, the velocity of the liquid
in the entire suction system is not truly constant but
varies in response to the combined demand of the
reciprocating plungers. Thus, liquid in the suction
system is compelled to be accelerated and decelerated
several times during each crankshaft revolution,
depending on the number of plungers. Called
“acceleration” head, this loss of available hydraulic
head is proportionalto:
(a) The speed (rpm) of the crankshaft
(b) The average liquid velocity in the piping
(c) The length of the suction piping
(d) The number of pumping chambers (triplex, etc.)
(e) The compressibility of the liquid
Thus, for a given pump, acceleration head effects may
be reduced by the use of the shortest possible suction
line, sized to reduce liquid velocity to a very low speed.
This is often more economical than the use of charge
pumps or suctionstabilizers.
NOTE: Charge pumps should be sized to 150% of rated
pump volume. Charge pumps need to be centrifugals,
not a positive displacement pump.
A charging pump is usually not a good substitute
for a short, direct, oversize suction line, nor is it a
substitute for the computation of available NPSH,
acceleration head, friction head, vapor pressure
and submergence effects duly considered. Required
NPSHR of Myers®Aplex Series pumps depends on
speed, choice of plunger size and valve spring type.
Consult Myers Aplex Series Engineering for help with
your particularapplication.
A common design mistake is the connecting of two
(or more) reciprocating pumps to a common suction
header. Each pump should be fed by its own separate,
individual piping system, free from the effects of other
pump cyclical demands forliquid.
DISCHARGE PIPING
A properly designed discharge piping system usually
prevents the need of a pulsation dampener. The most
common mistakes made in the design of the discharge
piping system are:
1. Pumping directly into a tee or header. A
“standing” wave (either audible or subaudible)
then often occurs. If flow must enter a header,
use a 45º branch lateral (or equivalent) to avoid a
reflecting surface from which sound canreflect.
2. Pumping into short radius 90º elbows. Instead,
use two 45º elbows spaced 10 or more pipe
diametersapart.
3. Pumping into a right angle chokevalve.
4. Pumping into too small piping line size. Piping
should be sized to keep fluid velocity below
15 feet per second,max.
5. Pumping through an orifice plate, small venturi
or reduced port “regular opening” valve.
6. Pumping through a quick closing valve, which can
cause hydraulic shock(water-hammer).
A good discharge piping system includes:
1. A properly sized, correctly set relief valve.
Discharge from relief valve returned to tank
(not to pumpsuction).
2. A full opening discharge gate or ball valve.
Avoid restricting plug valves, globe valves and
anglevalves.
3. A pressure gauge with gauge dampener or
snubber. Consider a liquid filled gauge.
(Scale range to be double the normal pump
operatingpressure.)
Locate the relief valve and pressure gauge ahead of
any block valve and so that the pressure in the pump
is always reflected at the relief valve. The relieving
capacity of the relief valve must exceed the capacity of
the pump to avoid excessive pressure while relieving.

11
Use a full size reliefline.
To minimize vibration (whether hydraulic or
mechanical), discharge lines should be kept short,
direct, well supported and solidly anchored. Avoid
“dead” ends and abrupt directionchanges.
BYPASS PIPING
Some designers ignore this important aspect of proper
design of pump pipingsystems.
A reciprocating pump, especially after maintenance of
the valves or plungers, starts with one or more fluid
chambers full of air. Pumps operating on propane,
butane or other volatile liquids start with vapor in the
fluidchamber(s).
Positive displacement pumps do not automatically
purge themselves of air and gas after shutdown.
For example, a quintuplex plunger pump will, after
servicing, expel the air in four of the five pump
chambers. Thus, the pressure from four of the “active”
cylinders will keep shut the discharge valve of the
“inactive”, or “air bound”, cylinder. Then, the air or gas
in this cylinder will be compressed and expanded by
its reciprocating plunger and never leave the chamber.
Similar effects occur in duplex and triplexpumps.
To overcome these difficulties, adequate provision for
expelling the gas in the “air bound” cylinders must
be present. Common practice is to totally relieve the
pump of all discharge pressure during the start-up,
afterservicing.
Consider the operational advantage of a full-sized
bypass line (return to tank) which substantially
removes discharge pressure from all cylinders during
the start. This requires a block valve on the discharge
side and a full opening bypass valve on the other side.
For economy, the bypass (to tank) can be combined
with the relief valve discharge line. This line must be
full-sized, well supported and sloped downward to
avoid freezing in cold weather. (A frozen relief valve
line provides no protection to either the pump or
operatingpersonnel!)
The ability of a reciprocating pump to be “self-priming”
depends on the ratio of the swept (displaced) volume in
the cylinder to the unswept (clearance) volume at the
end of the stroke. This depends on the design of the
fluid end and on the plunger sizeselected.
Choice of the largest size plunger for a particular fluid
end improves this compression ratio and so leads to
“self priming”, or easy priming. Choice of the minimum
size plunger sometimes leads to difficulties, especially
with pumps that require frequent servicing, or which
handle volatile liquids, or which contain substantial
amounts of dissolved air or gas. An automatic bypass
and purging system for these applications may
bemerited.
LUBRICATION
Myers Aplex Series pumps use S.A.E. 40 wt.
nondetergent oil in the crankcase. This oil requires
only a nonfoaming additive and should possess good
water separation (antiemulsion) characteristics.
Such oils are often labeled “industrial” or “turbine”
quality lubricants. If these oils are not available, a
good quality gear oil or EP oil may be substituted. See
lubricationguidelines.
In temperate climates, oil viscosity selected should
fall between 70 and 84 seconds Saybolt viscosimeter
at 210º F. In arctic service, low pour point oils
areneeded.
After the first 500 hours of operation in a new pump,
drain the oil. Refill with clean, fresh oil. Thereafter,
change the oil every 1,500 hours or sooner if it
becomes contaminated with water or dirt. Fill to the
center of the sight gauge. Recheck after starting,
adding oil to center of gauge whilerunning.
V-BELT DRIVE
A properly designed, well-aligned V-belt will provide
years of reliable, economical service if properly
tensioned and kept dry, free of oil and ventilated.
Alignment is critical for long life. If the shaft axes are
not truly parallel, or if the sheave grooves are not
positioned in good alignment, some belts will carry
most of the load, resulting in their disproportionate
load share and may actually twist or turn over in the
groove. Use a straight edge across the rim of the
sheaves to detect and correct formisalignment.
After about one week of operation, new V-belts will
have stretched somewhat. The motor must be moved
on its slide base to re-establish proper belt tensioning.
Insufficient tension results in slippage, burning,
squealing (especially during starting) and shortened
belt life. Overtightening imposes excessive loads on
pump and motor bearings and can cause early shaft
fatiguefailure.

12 13
NOTES
1) CENTERLINE OF PUMP SUCTION (INLET) TO BE SLIGHTLY HIGHER THAN CENTERLINE OF SUCTION (INLET) VALVE, SO ANY AIR IN SUCTION SYSTEM PROMPTLY REACHES THE PUMP AND IS EXPELLED. 2) SLOPE BYPASS SO LOW POINT DRAIN WILL FULLY
EMPTY RELIEF AND CHOKE VALVES AND ALL
LIQUID IN BYPASS CIRCUIT.
3) DO NOT LOCATE PIPING OR OTHER EQUIPMENT IN FRONT OF OR ABOVE PUMP LIQUID END, PREVENTING SERVICING. 4) LOCATE CHARGING PUMP AT POINT SHOWN IF
A
CHARGING PUMP IS NECESSARY (AS FOR VOLATILE FLUIDS, FOR EXAMPLE).
5) IF DESIRED, A TWO-WAY MOTOR-OPERATED BYPASS
VALVE MAY BE USED RATHER THAN A MANUAL TYPE. IT SHOULD BE DESIGNED TO OPEN AUTOMATICALLY WHILE STARTING OR STOPPING.
6) FEED LINE AND BYPASS LINE SHOULD FEE
D
LIQUID INTO TANK BELOW MINIMUM LIQUID LEVEL
.
LIQUID SUPPLY TANK
SUGGESTED PIPING SYSTEM FOR PLUNGER PUMPS
BYPASS LINE
FULL-OPENING SUCTION (INLET) LINE VALVE
LOW POINT DRAIN VALVE (SEE NOTE 2)
FLEXIBLE HOSE OR EXPANSION JOINT (SEE NOTE 7)
NEEDLE OR HARD-TRIMMED CHOKE BYPASS VALVE OPEN TO
EXPEL AIR IN PUMP PRIOR TO LOADING (SEE NOTE 5)
FULL-OPENING RELIEF VALVE OR BURST-DISC
VALVE OPENS FULLY WHEN SET PRESSURE IS
REACHED
HORIZONTAL PLUNGER PUMP WITH DUAL SUCTION AND DUAL DISCHARGE
CONNECTIONS (DRIVER AND FOUNDATIONS NOT SHOWN)
PRESSURE GAUGE AND BLOCK VALV
E
DISCHARGE PULSATION DAMPENER (IF USED
)
SUCTION PULSATION DAMPENER (IF USED)
DISCHARGE LINE (SEE NOTE 7)
FULL-OPENING DISCHARGE LINE VALVE
SWING CHECK VALVE WITH FULL-OPENING SEAT
PRESSURE RELIEF VALVE AND COLD WEATHER DRAIN (SEE NOTE 9)
CENTERLINE OF PUMP SUCTION (INLET) (SEE NOTE 1)
ECCENTRIC REDUCER WITH FLAT SIDE UP
PRESSURE GAUGE AND BLOCK VALVE
FLEXIBLE HOSE OR EXPANSION JOINT (SEE NOTE 7)
SUCTION (INLET) LINE. SEPARATE LINE REQUIRED FOR EACH PUMP IF MULTIPLE PUMPING UNITS ARE USED. SIZE OF LINE DEPENDS ON ACCELERATION HEAD FACTOR BUT MUST AT LEAST EQUAL PUMP SUCTION CONNECTION SIZE. (MINIMUM)
SEE NOTE 4
VORTEX SPLITTER AND SUPPORT
SUCTION BELL. DESIGNED FOR LOW LIQUID ENTRY VELOCITY (MAY INCLUDE FOOT VALVE IF DESIRABLE)
COMPLETELY SUBMERGED BAFFLE PLATE SEPARATING INCOMING FROM OUTGOING LIQUID
MANHOLE
MINIMUM LIQUID LEVEL
FEED LINE (SEE NOTE 6)
7) TO REMOVE PIPING STRAIN AND VIBRATION, A
FLEXIBLE HOSE, EXPANSION JOINT, OR SWIVEL JOINT PAIR SHOULD BE POSITIONED TO MINIMIZE EFFECTS OF PIPING THERMAL EXPANSION, CONTRACTION AND PIPING WEIGHT. 8) SUCTION AND DISCHARGE PIPING MUST BE SUPPORTED AND ANCHORED. 9) TO PROTECT SUCTION SYSTEM AGAINST
HAZARD OF DISCHARGE PRESSURE ENTRY (AS WHEN PUMP IS IDLE) A SMALL RELIEF VALVE IS OFTEN CONNECTED HERE. 10) ALL SYSTEM CONPONENTS MUST HAVE ADEQUATE PRESSURE RATINGS FOR OPERATING, STARTING, AND UPSET CONDITIONS IN ORDER TO REDUCE POTENTIAL HAZARDS, PARTICULAR ATTENTION IS RECOMMENDED FOR THE SURGE CONDITION THAT WILL RESULT DOWNSTREAM OF THE RELIEF
VALVE WHEN NORMAL DISCHARGE IS BLOCKED.

13
Use the following table in adjusting V-belttension:
Belt Tension at Mid-Span
Cross-Section New Belts Used Belts
“B” 5 – 6 lbs. 3-1/4 – 5 lbs.
“C” 9-3/4 – 13 lbs. 6-1/2 – 9-3/4 lbs.
“3V” 4 – 10 lbs. 3 – 7-1/2 lbs.
“5V” 17 – 30 lbs. 13 – 23 lbs.
Applying the above forces with a small spring
scale, adjust motor position to provide the following
deflection atmid-span:
Approx. Center Distance
(Span), inches
Deflection,
inches
16 1/4
22 3/8
28 7/16
32 1/2
40 5/8
48 3/4
60 15/16
Belts must be matched in pitch length. If one or
two belts are slack, when the others are correctly
tensioned, investigate for possible reasons. Correct
any misalignment or lack of matching so each belt will
transmit its loadshare.
Sheaves must be balanced to prevent abnormal
vibration. Balancing weights must not be removed.
Type “QD” sheaves must be evenly tightened on their
tapered hubs to avoid rim wobble and severe lateral
vibration. V-belts that snap and jerk will produce
abnormal vibration and loads on both pump and motor
orengine.
Run the pump several minutes at full load with belt
guard removed, observing for uneven motion on the
belt slack side,especially.
When an old V-belt drive becomes unserviceable,
replace all belts, not just the broken or cracked belts.
Do not operate belts on sheaves having worn, rusted,
greasy or broken grooves. Shut off power to driver
before servicing drive or pump.
WARNING: Do not operate without appropriate guards
in place.
DIRECTION OF ROTATION
Before placing pump in operation, check that
crankshaft rotation agrees with the arrows cast on
top of the power frame by briefly jogging the electric
motor. Crankshaft rotation must be clockwise as
viewed from the right side ofpump.
If pump is gear driven, remember that the pinion
shaft turns opposite the crankshaft, if using a single-
reduction geared drive or in the same direction as the
crankshaft when using a planetarygear.
AUTOMATIC (SAFETY) SHUTDOWNS
Carefully check all electric shutdown devices present,
such as crankcase oil level, discharge pressure,
vibration, lubricator oil level, motor thermostat,etc.
CRANKSHAFT ASSEMBLY
GENERAL
Myers Aplex Series crankshaft suspension uses two
single-row tapered bearings, which are shim adjusted
to provide the correct runningclearance.
Thorough cleaning of all components prior to assembly
isessential.
Power frame, shaft, bearings and retainer must be
scrubbed with clean solvent (such as kerosene) before
starting. Remove any oil, dirt, rust and foreign matter
which might prevent the correct fitup.
Crankshaft journals are critical. Remove all burrs, rust
spots and nicks, paying special attention to the ground
areas on which bearings and oil seals operate.
Connecting rods and crossheads must be
previously installed into CA-125M pumps before the
crankshaftassembly.
TAPERED ROLLER BEARINGS
Shaft and frame tolerances provide a tight (shrink) fit
on the shaft and in the carrier. The best way to install
the cone assembly (consists of the inner race, cage
and rollers) on the shaft is to heat the cone assembly
in an electric oven for 30 minutes at 300 to 400ºF.
(Do not heat bearings with an acetylene torch. This
ruins the bearings!) Using clean, insulated gloves,
remove the hot cone assembly from the oven, promptly
dropping it on to theshaft.
The cone assembly must contact the seat thrust face
(not be cocked), and the large end of the rollers must
be down. Do not hammer on the bearing. The soft steel
cage is easily distorted, ruining its function as a roller
separator and guide against skewing. If the cone does
not contact its thrust face properly, it must be pressed
into place using a specially machined sleeve (which
does not touch the soft steel cage). A hydraulic press is
recommended if this difficultyarises.
CUP INSTALLATION
Tapered roller bearing cup (outer races) is a press-fit
in the bearing carrier, using a hydraulic press. Cup
must be pressed into a clean carrier until the race
solidly abuts its shoulder (must not becocked).

14 15
The tool or plate used for this must contact only the
outer end face – not on thetaper.
INSTALLING CRANKSHAFT
SHIM ADJUSTMENT OF TAPERED
ROLLER BEARINGS
To provide for crankshaft thermal expansion, sufficient
shims (located beneath bearing retainer flange) must
be installed to provide .005" to .015" lateral end play,
when shaft iscold.
A feeler gauge and a 1" micrometer caliper are
required. Install a trial shim set on one side of the
pump. Tighten the flange bolts on this sideonly.
CAUTION: Lubricate the frame bores and the O-ring
seals located in each carrier to prevent damage during
entry. Oil thebearings.
Omitting the shim set on the opposite side, draw up
the carrier, evenly tightening its cap screws. Rotate
the crankshaft slowly by hand, seating all rollers into
runningposition.
Measure the gap existing between the frame face and
carrier flange. The correct thickness of the shim set to
be installed on this side equals the measure gap plus
about .010". (Nopreload)
After installing above shim set, a dial indicator may be
used against the end of the shaft to confirm the shim
selection. Bump the shaft in one direction and zero
the dial indicator. Bump the shaft the opposite way. If
shimming is correct, the shaft will move laterally from
.005" to.015".
About equal shim set (totals) are required under each
carrierflange.
The recommended tightening torque for bearing
retainer 3/4"-10UNC cap screws is 211 to 257 ft.lb.
INSTALLATION OF CRANKSHAFT OIL
SEAL
Insert oil seal over the end of crankshaft and position
it into the oil seal bore in the power frame of bearing
retainer. Using a rubber mallet, tap it into the bore
until the face of the seal is flush with the power frame
or bearingretainer.
DISASSEMBLY
After removing the connecting rod cap and cap bolts
(note identifying marks on each cap so each may be
later correctly reassembled onto its own rod) remove
a bearing carrier from the frame. Two jack out tapped
holes are provided in the flange of the carrier for
this purpose. Support the shaft during removal to
avoiddamage.
The crankshaft may now be extracted, once all
connecting rods are moved clear. Examine the
crankpin surfaces for wear or corrosive pitting. The
correct diameters of these journalsare:
Crankpin Diameter .................................4.5000/4.4990"
If worn more than .010" undersize, crankshaft should
be replaced, or an attempt to salvage it may be made
at a shop well equipped to grind the crankpins which
must be fully round, chrome plated and finish ground
to the above sizes. (Myers Aplex Series does not
perform thisfunction.)
Crankshaft tapered roller bearings should be carefully
examined for pitting, scoring or corrosion, and
replaced as required. The cone and roller assembly
is most easily removed by first cutting away the cage
using an acetylene cutting torch. Then heat the cone
(inner race) with the shaft held vertically so cone will
drop off due to its own weight. Avoid excessive heat on
the crankshaft which tends to distort itsgeometry.
Cups (outer races) of tapered roller bearings may be
extracted from bearing carrier using a conventional
bearing puller tool of the automotive type (widely
available). Do not attempt to use heat on a bearing
carrier as this will result in severe distortion (out-of-
round). Replace the bearing carrier, if broken or
out-of-round.
CONNECTING ROD, CROSS-
HEAD, EXTENSION ROD,
CROSSHEADPIN AND WIPER
BOX ASSEMBLY/DISASSEMBLY
GENERAL
Myers Aplex Series connecting rod assemblies employ
precision automotive type steel backed, Babbitt-lined
crankpin bearing halves which require no shims for
clearance adjustment. This pump employs full circle
(piston type) crossheads and hardened stainless steel
extension rods, which are fieldreplaceable.
Extension rods are provided with wrenching flats
to permit tightening of the tapered thread into the
crosshead, establishing accurate alignment while
affording easy fieldinstallation.
Before beginning the assembly all parts must be
cleaned, removing all oil, dirt, rust and foreign matter
which prevent proper fitting, or which might tend to
score the rubbing surfaces. Clean and examine the

15
power frame bores for scoring and abnormal wear,
especially wear of the lower crosshead guide way.
Hone smooth, ifrough.
Measure the bores of the frame using inside
micrometers to determine abnormal frame wear ifany.
Crosshead O.D.: 6.740/6.737
New Frame Bores: 6.749/6.752
Frame bores that have become worn more than .015"
must be sleeved with a cast iron liner to re-establish
correct geometry and alignment. Contact Myers
Aplex Series concerning the repair of badly worn
framebores.
Smooth any rough corners and edges on the crosshead
skirts, using fine emery cloth. Examine and clean the
female tapered threads and wrist pin holes.
INSTALLING WRIST PIN BUSHINGS
The wrist pin bushing is precision machined bearing
bronze which is press fitted into the eye of the
connectingrod.
Bushing O.D.: 3.2525/3.2515
Connecting Rod Eye: 3.250/3.251
*MA-155 requires two bushings per crosshead.
After applying oil to the bushing O.D., use a hydraulic
press to force it home. Repeat this procedure for the
second bushing. When a bronze bushing is pressed
into place, the I.D. (bore) of the bushing is reduced
somewhat, owing to the extent of press fit. Therefore,
a clean, new wrist pin should be inserted into the
bushing bore to establish that running clearance has
been obtained. The running clearance between the
wrist pin and installed bushingis:
New Pin O.D.: 2.6875/2.6860
Installed Bushing Bore: 2.6895/2.6905
Oil Clearance.............................................. .0020/.0045"
Replacement bushings are furnished prebored by
Myers Aplex Series which usually eliminates the
need to ream the installed bushing bore. However,
due to slight variations in finishes and tolerances
it sometimes happens that more than predicted
contraction of the I.D. occurs. This occurrence results
in a slight interference which may be eliminated by
lightly honing the bore of the bronze. (Not by reducing
the pin size!) An automotive engine repair shop usually
is equipped with power honing machines capable of
smoothly finishing the bushing bore. Bore of bushing
must be round and free oftaper.
BOLTING THE WRIST PIN
After pressing in the two bronze bushings, the wrist
pin must be bolted to the connecting rod. Place the
connecting rod inside the crosshead and slide the wrist
pin through the crosshead and connectingrod.
The hole in the wrist pin should line up with the hole in
the connecting rod. Install the shoulder bolt through
the wrist pin and thread into connectingrod.
Torque to 25 ft/lbs.
After installing the pin, carefully check the crosshead
O.D. to see if it is out-of-round. If so, a smart blow with
a rubber mallet will restore the crosshead O.D. into its
originalroundness.
ORDER OF ASSEMBLY
Prior to January 2015, the connecting rod/crosshead
assembly is installed before the crankshaft is installed,
because the wiper box wall bore is smaller than the
crossheadO.D.
This is most easily done by setting the power frame
vertically and dropping each crosshead assembly into
its framebore.
Note: The connecting rod must clear the frame
bore circle in order to introduce the crankshaft in
thesemodels.
As of January 2015, the connecting rod/crosshead
assembly is installed after the assembly of the
crankshaft. In these models, the rod and crosshead
will pass through the wiper box wall bore. With the
frame in the horizontal position, load the rods through
thecradle.
New Crankpin O.D.: 4.5/4.499
New Connecting Rod Bore: 4.851/4.853
Crankpins that are worn out-of-round, tapered, or
badly scored should either be discarded or perhaps
salvaged by grinding undersize, hard chrome-plated,
and finish ground to above diameter. (Myers Aplex
Series does not offer thisservice.)
Connecting rod/cap bore must be perfectly round
and within above sizes and free of taper. Discard,
if elliptical or tapered as the result of abnormal
heating. Each cap and rod is match-marked for correct
identification. Take care that each cap is reinstalled
properly with its companion rod. Bearing halves are
identical and are prevented from rotating by tongues
which fit into slots in thecap.
Check that all oil holes are clean and fully open. Grit
is the greatest enemy of bearings, however precisely
manufactured. Hence, all surfaces must be perfectly
clean and lightly oiled prior to assembly. Remove any
burrs or sharp corners which prevent the perfect

16 17
fitting of these precision bearings. Using a torque
wrench, tighten cap bolts asfollows:
Thread Size: 5/8" – 18UNC
Tightening Torque: 125-135 ft/lbs.
Specified torque, applied to clean, well oiled threads
and bearing faces, will create tensile stresses in the
cap bolts from 90,000 to 110,000 psi, approx. and will
provide correct initial tension. Myers Aplex Series
pumps use high strength cap bolts suitable for these
initial loadings, maintained by safety wire to keep the
requiredtightness.
After all rods and caps are secured, slowly turn the
crankshaft to be sure no bearings are in abind.
Examine the location of each connecting rod (eye
end) within its crosshead. Rods must not touch any
crosshead boss orskirt.
OIL SCOOP
(Before Jan. 2015 Only)
This pump is provided with a bronze oil scoop which
shears off oil adhearing to the crankshaft cheek,
depositing oil on the deck above the crossheads,
assuring adequate lubrication even at low
pumpspeeds.
The scoop is adjustable in position, and is set lightly in
contact with the crankshaft. Secure it, tightening the
self-locking nuts securely. Note that fiber washers are
employed underneath the bolt heads, preventing oil
seepage to theoutside.
WIPER BOX ASSEMBLY
GENERAL
Extension rod wiper boxes (sometimes referred to
as the diaphragm stuffing box or stripper housing
assembly) serve two important functions: retention of
crankcase oil in the power end and exclusion of dirt
andwater.
Myers Aplex Series has developed a unique sealing set
which operates on a hardened and ground stainless
steel extension rod (often called “pony” rod), and a
steel baffle disc affording protection against leaking
plunger packing. The seals require no adjustment, only
correct and carefulassembly.
POLY PAK ® SEAL
(Before Jan. 2015 Only)
This seal keeps oil from leaking out of the power
frame. Developed by the Parker Seal Group, this
patented rod seal employs a soft nitrile rubber O-ring
to energize a special hard polyurethane Molythane®
shell by forcing the inner lip against the rod and the
outer lip against the housing bore, asshown.
The Poly Pak seal is inserted into its counter bore with
its lips directed toward the oil in the crankcase. (Will
not work if installedbackward!)
MECHANICAL OIL SEAL
(Before Jan. 2015 Only)
The oil seal is to keep contamination out of the power
frame. With the box positioned in a hydraulic press,
install the backup seal against the Poly Pak seal, with
the lips of both seals facingdownward.
The mechanical seal contains a garter spring. Check
to see that this spring is still properly located and in
its position. The mechanical seal has a metal case
which serves to force the Poly Pak seal into its cavity,
energizing its lips. Apply oil lightly to the bore of the
box before pressing each seal into its counterbore.
DOUBLE-LIP WIPER SEAL
(Jan. 2015 to Current)
This seal keeps oil from leaking out of the power
frame. Developed by the Parker Seal Group, this
double-lipped wiper provides an additional beveled
sealing lip, yielding excellent film-breaking and the
driest rod sealingavailable. The double-lip wiper seal
is inserted into its counter bore with its lips directed
toward the oil in the crankcase. (Will not work if
installedbackward!)
DOUBLE-LIP CANNED WIPER
(Jan. 2015 to Current)
The double-lip canned wiper oil seal is to keep
contamination out of the power frame. This seals press
fit installation prevents O.D. contamination while the
additional seal lip works in conjunction with Parker
rod seals to provide sealing for leakage. An aggressive
wiping lip, facing the element, ensures contaminant
exclusion along the rod.
INSERTING THE EXTENSION ROD
Insert the extension rod through the wiper seals with
the tapered thread and entering first. Care should be
used in moving the extension rod through the seals
with wrenching flats entering first. Do not force! The
sharp corners on the wrenching flats may damage the
seal lips! (Resulting in oil leakage.)
With extension rod inserted through the wiper box

17
seals, thread the tapered threads (must be clean!) into
the tapered crosshead female threads. Firmly tighten,
applying torque to the wrenching flats only. Never
damage the extension rod groundsurfaces!
Then fasten the wiper box to the power frame by
tightening the cap screws. Oil leakage between frame
face and wiper box is prevented by use of a gasket
beneath the boxflange.
STUFFING BOX, PACKING AND
PLUNGER ASSEMBLIES
GENERAL
Myers Aplex Series pumps all feature field removable
and replaceable stuffing boxes with plungers
separable from the extensionrods.
If desired, the boxes, plungers, and packing units
may be installed (or removed) as a unit assembly,
permitting service outside the pump. All boxes are
retained by four studs and nuts, and are centered in
the frame bore, ensuring correctalignment.
The plungers may also be removed separately (without
box removal) to facilitate repacking. With this option,
the necessary space required to remove plunger, it is
first necessary to remove the extensionrod.
SPRING LOADED PACKING
Note that the gland is screwed tightly onto the box
and contacts its face. The spring is providing all of the
initial compression and adjustment. No adjustment is
provided by thegland.
Since the force exerted by the spring is contingent
on the space provided for it, the correct lengths of all
rings are essential for goodtensioning.
Spring:
A stiff Inconel®spring, which closely fits the bore of
the stuffing box, is used in this assembly. This spring is
compressed in a vise to the operating length required
plus 0.25" and tied with waxed nylon spot tie cord. The
cord is looped over the ends of the spring through the
coils and tied to maintain the length mentioned above.
Each spring is assembled into the stuffing box. Note
that the spring does not contact theplunger.
Spring-Guide Ring:
Plungers are heavy and the importance of a well-fitted
guide ring that carries this weight is often overlooked.
Discard any guide ring that becomes worn or scored,
as it will then not serve its purpose. It should fit snugly
in the box. Apply oil generously to this ring.
Spring Loaded Packing:
Three rings of chevron or compression packing
are installed next. For compression packing, install
them with the skive intersections 180º apart to
discourageleaking.
Gland Ring:
This ring also fits the plunger and helps support the
plunger weight. Discard it if bore is worn, rough or
out-of-round. Lightly oil the ring before insertion. The
gland ring fits allpacking.
J-STYLE STUFFING BOX & PLUNGER
ASSEMBLY (STYLES 838 & 858)
Styles 838 and 858 packing is installed with all packing
lips facing toward the fluid pressure. Note that two
units of Styles 838 and 858 packing are positioned
ahead of the lantern ring, and one unit is positioned
behind it. Thus lubricant entering the lantern ring is
forced toward thepressure.
Throat Bushing:
Plungers are heavy and the importance of a well-
fitted throat bushing that carries this weight is often
over- looked. Discard any throat bushing that becomes
worn or scored, as it will not then serve its purpose.
It should fit snugly in the bottom of the box. Apply oil
generously to thisring.
Styles 838 and 858 Packing:
Developed by Utex Industries, Inc., Styles 838 and
858 are a nonadjustable type packing which depends
solely on hydraulic pressure to energize the sealing
lips. (Gland-tightening forces do not energize the
lips.) Tightening and hydraulic end thrust loads are
transmitted entirely through the center support
portions of eachring.
The flattened portions of the rings are large enough to
withstand overtightening. Do not attempt to adjust this
type packing. It should be kept thoroughly tightened at
all times. (Running it loose will ultimately ruin the bore
of thebox.)
Running it loose will not usually cause it to drip at all,
but it can ruin the box intime.
Lightly oil each ring and the box bore and then lightly
tap in each ring separately with the rings facing
correctly. This is most easily done before installing
theplunger.
Lantern rings are provided with O.D. and I.D. reliefs
and two (or more) oil holes to allow lubricant to reach
the plunger. After the last unit of Styles 838 and 858
packing is in place, generously oil the lips of all seal
rings to ease plunger entry.

18 19
INSERTING THE PLUNGER
Apply oil liberally to plunger O.D. and lightly tap it
through the packing. When introducing the plunger
through the MA-155M stuffing boxes, also apply oil
liberally to the O.D. of each extension rod to allow easy
passage through the wiper boxseals.
A soft rubber mallet is recommended to avoid any
damage to the plunger face or its threads. Remember:
The fragile nature of packing rings and plunger
surfaces deserves your respect and avoidance of
careless damage to these keyelements!
INSTALLING THE GLAND
Considerable downward pressure on the gland is
required to compress the spring, to move the packing
into location, and to start the threads of thebox.
Once the gland threads are started, screw it down
completely until it makes up tightly against the face of
the box, for spring loaded packing. For Hi/Lo, J-Style
or Gland adjusted packing, tighten the gland until it is
seated firmly against thepacking.
INSTALLING THE STUFFING BOX
Myers Aplex Series stuffing boxes derive their
alignment from the bores of the power frame and
the faces of the fluid end. So these surfaces must be
cleaned of rust, scale, and dirt before assembly is
begun. Wash all contacting surfaces with clean solvent
and dry with a clean shoptowel.
A nitrile rubber seal is used to seal between the face of
the fluid end (must be flat, clean and smooth) and the
face of the box. Replace ifdamaged.
All stuffing boxes are retained by four large studs and
nuts which extend through the power end, serving to
clamp the box and the power frame tightly against the
fluid end face. These four stud nuts must be
evenlytightened.
Using a socket, socket extension, and torque wrench,
tighten clean, well-oiled threads and nutfaces.
Stud Threads
1-1/4" – 8UN at
900–950 ft/lbs.
SC-230
MA-155L
MA-155M
MA-155M-HD
CONNECTING THE PLUNGER
Install the metal baffle plate on the extension rod
and roll the pump slowly until the extension rod male
threads just touch the mating plunger femalethreads.
Applying a pipe wrench to plunger knurled area,
thoroughly tighten the connection. Do not use a
“cheater” when connecting plunger to extensionrod.
PACKING
Packing life for aramid fiber packing may be improved
in some applications by regular, systematic lubrication.
An optional force feed lubricator assembly is often
recommended especially for pumps on continuous
duty. This provides regular, controlled supply of
lubricant lowering friction andheat.
Additionally, the regular application of the correct
lubricant aids dissolving of salt and gyp tending
to build up on the plungers in produced water
applications. For this service, Rock Drill Lubricant is a
popular and effective packinglubricant.
Plungers in CO2, ethane, or other very cold liquid
services may use brake fluid. This fluid does not
congeal into a solid which cannot enter the packing.
Consider the use of an air-sealed cradle into which
dry (instrument) air may be directed, excluding the
moisture which causes plunger icing especially in very
humidconditions.
Packing lubricant for pumps on light hydrocarbons,
hot water, lean oil, naphtha or gasoline often
requiresexperimentation.
A good start is to use steam cylinder oil. Castor oil
is sometimes successful as a packing lubrication
for liquid propane and butane services, at
ambienttemperature.
In pumps placed in arctic service, a special low pour
point oil isindicated.
Packing lubrication is not permitted on some services,
such as amine, food stuffs, etc., and other packing
styles and materials may berequired.
PLUNGERS
Myers Aplex Series offers its own unique product: the
Myers Aplex Series Rokide®plunger. This premier
quality plunger consists of a chromium-oxide
deposition on a solid stainless steelbody.
Ordinary handling will not damage this fine product.
Avoid striking the coated surface (black) during
installation. Apply light forces only on the ends of the
plunger. Do not hammer orpry.

19
All threads on Myers Aplex Series plungers must
be clean and oiled before assembly. Stainless steel
(although very corrosion resistant) has a tendency to
gall and seize. To avoid this, an anti-seizing lubricant
is well worth its use. Apply oil to the threads and the
rubbingsurface.
Myers Aplex Series can supply solid ceramic plungers
on order. This plunger is very fragile, vulnerable to
thermal and mechanical shock, and must be handled
with the greatest care. Use only a rubber mallet to
insert it into the packing. Other plunger types are
available uponrequest.
DISC VALVE SYSTEMS AND
ABRASION RESISTANT VALVE
CONSTRUCTION
GENERAL
Myers Aplex Series has developed a unique setting/
puller system permitting quick, easy and safe methods
of installing and removing tapered seatvalves.
The system allows servicing without distortion of the
seat, with minimum effort and no damage to fluid end
tapers orseat.
DISC VALVE AND ABRASION
RESISTANT VALVE CONSTRUCTION
The Myers Aplex Series valve is a precision made
subassembly using threads cut into the rim of seat
for use with Myers Aplex Series setting/pulling tool.
These threads do not deteriorate as proved by field
experience. By locating these on the rim, setting/
pulling forces are now applied only to the rim of the
seat, never to the webs (or “spokes”), or to the center
section. Distortion of the seat iseliminated.
Access to these seat threads is provided by the
removal of the valve cage on abrasion resistant valve
or the spring retainer on disc valves which is screwed
onto the seat. An anti-seizing lubricant applied to all
threads is good insurance against futuredifficulty.
SETTING THE VALVE SEAT
Effective pressure-sealing between tapered (male)
seat and tapered (female) fluid end deck is possible
only if the tapers are absolutely clean and dry just
prior to installation. Thoroughly clean surfaces using a
clean solvent. Dry with a clean shoptowel.
Examine the cleaned fluid end deck tapers and remove
all deposits of gyp, salt, or other incrustation. Using
emery cloth, lightly rub out any minor imperfections
found in the decktaper.
The puller stem and puller head are provided with
tapered (locking) threads. Screw them together using
two pipe wrenches applied to the knurled areas
provided. Then screw the valve seat onto the puller
head by hand until it shoulders against the puller
shoulder. Do nottighten.
Lower the seat and puller assembly into the fluid end,
squarely setting the seat into the deck. Then pound the
top of the stem with a 6 poundhammer.
Unscrew the head and stem from the seat using a 1/2"
bar (or screwdriver) into the hole provided at the top
end of thestem.
INSTALLING O-RINGS, ABRASION
RESISTANT SPRING AND CAGE
Install nitrile O-ring over the threaded section of the
seat and position it at the bottom of the threads. Install
the polyurethane insert into the valve. The insert may
be heated in hot water to make it flexible enough to
stretch over the valve. Position the valve into the seat.
Install the valve spring. Apply anti-seizing lubricant to
the threads of the valve cage and screw the cage on to
the threaded valve seat with cage settingtool.
INSTALLING DISC, SPRING,
DISC VALVES AND STEM
Myers Aplex Series offers discs of acetal resin, of 17-
4PH S.ST. hardened and ground, and of titaniumalloy.
Position the disc and Inconel spring on the seat,
aligning the hole in the disc with the stem threads in
the seatcenter.
The stem, spring retainer, and locknut are shipped
from Myers Aplex Series already assembled and
tightened with a torque wrench with Loctite® sealant
added to the top stem threadsonly.
Stem Threads Tightening
Torque
1/2"-13UNC 65-75 ft/lbs.
Use an anti-seizing lubricant in these threads. This
is very necessary when seats and stems of Type 316
stainless steel are selected (optional) to prevent
galling. Cleanliness of threads and other contacting
surfaces is of paramount importance in the assembly
of all valveelements.

20 21
VALVE SPRING OPTIONS
All Myers Aplex Series valve springs are made of
Inconel material, precisely designed and fabricated.
Unless otherwise specified, the standard spring is
furnished. It provides excellent results in the great
majority ofapplications.
Pumps employed in marginally available NPSH
conditions may require a softer spring, to reduce the
required NPSH. For these special conditions, Myers
Aplex Series can supply light valve springs which exert
lower pressure on the valve disc. The use of light valve
springs may be limited by the choice of plunger size
and/or limited by the chosen speed of the pump. Light
valve springs may be impractical for pump models
fitted with their maximum plunger size, or which
operate near top speed rating as disc bouncing and
erratic seating mayoccur.
VALVE DISC OPTIONS
Myers Aplex Series acetal resin discs are machined
flat and smooth to produce perfect sealing on the
lapped-flat face of the seat. Used successfully in
thousands of applications, these discs are light,
slightly flexible under load, and seal well, even at high
pump speeds, providing smooth pumpaction.
Acetal resins are very resistant to most corrodents,
but are not usually suitable where fluid temperatures
are above 120 degrees. Nor do they afford long life at
extreme pressures. Pressure limitations depend on
valve size. But continuous valve operation at pressures
above 2,500 psi usually indicates the need of metal
valvediscs.
For higher temperatures or pressures, Myers Aplex
Series offers lapped flat, hardened Type 17-4PH
stainless discs, or titanium alloy discs. These metal
discs are less tolerant of any fine grit in the liquid and
are noisier than the acetal resindisc.
PULLING THE VALVE SEAT
First drain the fluid end entirely. For abrasion resistant
valves, use the cage wrench to unscrew the cage from
the seat. For disc valves unscrew the stem from the
seat. Remove the cage, spring and valve from the fluid
end. Attach the Myers Aplex Series puller head to
the puller stem, tighten their tapered threads with a
pipe wrench applied to the knurled areas of the puller
stem and head. Lower the stem and head into the
fluid end and engage the threads of the head onto the
seatthreads.
Using a 1/2" bar (or screwdriver), rotate the head
clockwise and thread it fully onto the seat. But do
nottighten.
Slide the bridge over the stem. Clean and oil the stem
threads. Oil the face of the wing nut. Thread wing nut
down onto the stem, seating it on the bridge top firmly.
Extract the seat from the pump by striking the wing
nut with a heavy hammer. A hydraulic ram may also
be used. Stand clear of the pump when applying heavy
tonnage, as the entire assembly will jump violently
upward when the pulling energy is suddenlyreleased!
The Myers Aplex Series puller/setting tool and gauge
tool are custom designed and built for each specific
Myers Aplex Series pump model. The same puller
head is used on both suction and discharge seats.
The bridge is made to fit each model, and its proper
use will not damage the valve cover gasket machined
counterbore on the top of the fluidend.
SALVAGE OF WORN SEATS
Rough valve seat faces may often be renewed by
lapping or grinding, if not deeplyfluid-cut.
Perfect flatness is required. A surface grind, followed
by lapping on a lapping plate, provides excellent
smoothness and the flatness needed for good sealing
and smooth running. Metal valve discs may sometimes
be salvaged by grinding or lapping, if not deeply cut
orcracked.
Acetal discs are relatively inexpensive and salvage is
seldom worthwhile. Replace the stem, if severely worn.
Inconel valve springs rarely requirereplacement.
OTHER PUMP BRANDS
Myers Aplex Series Industries can provide its unique
(patented) valve to fit nearly all brands and models of
multiplex pumps. A Myers Aplex Series seat setting/
puller tool is available,too.