Pumptec 348U Series User manual

Version 100522 Pumptec, Inc. | 700 McKinley St. NW, Anoka, MN 55303 | 763-433-0303 | www.pumptec.com
Please read and save these instructions. Read carefully before attempting to assemble, install, operate, or maintain the
product described. Protect yourself and others by observing all safety information. Failure to comply with instructions could
result in personal injury and/or property damage in which Pumptec, Inc. will not assume any liability for! Retain instructions
for future reference. Refer to the following video to assist in pump reconstruction:
350U Pump Rebuild Tutorial
PUMP SERIES
348U | 350U
PERFORMANCE FEATURES
•Long Life
•High-Pressure
•High-Efficiency
•Serviceability
•Durability
•Application Flexibility
•Chemical Compatibility
•Compact Design
•Enhanced Priming
Pumptec pump series 348U|350U with plunger type design is the most efficient way possible to pressurize
water. This efficiency produces up to 20% more pressure or flow for a given power input compared to
competitive pumps. The series offers a variety of pump and motor combinations customized to meet specific
application requirements. Typical applications include pressure cleaning, pest spraying and misting. All pumps
are factory lubricated for long-life performance. The only tool to completely disassemble the pump to its basic
components is a 3/16” hex wrench. Durability and performance results from exclusive use of premium
materials. All metallic wetted parts are stainless steel. An aircraft-grade anodized aluminum pump is nearly
indestructible compared to pumps made of castings. The body offers chemical compatibility with a wide variety
of chemicals. Flow and pressure can be optimized to exactly match power input to nozzle size, and offers an
assortment of eccentrics for low, medium, and high pressure to match your application requirement.

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
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Version 100522
UNPACKING
Remove all packing materials. Carefully remove the plunger
pumps from the shipping carton. Inspect for any damage that
may have occurred during transit. Check for any loose, missing,
or damaged parts.
SPECIFICATIONS
Maximum specifications refer to individual performance levels
and may be conditional on other factors. Consult the
Troubleshooting section when operating near any performance
maximum and refer to individual pump data sheets for
complete specifications, parts list, and exploded view.
Model 348U
MAX PRESSURE . . . . . . . . . . . . . . . . . . . . . . . . . TO 1000 PSI
OPEN FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . TO 3.7 GPM
SEALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U-CUP
O-RINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VITON
INLET PORTS (2) . . . . . . . . . . . . . . . . . . . .1/2" OR 3/8” F NPT
DISCHARGE PORTS (2) . . . . . . . . . . . . . . 1/2" OR 3/8” F NPT
MAX FLUID TEMP . . . . . . . . . . . . . . . . . . . . . . . . . .TO 140˚F
MATERIALS OF CONSTRUCTION
BODY . . . . . . . . . . . . . . . . . . . . . . . HARDCOAT ALUMINUM
PLUNGER . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . 304 SS
VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . .STAINLESS STEEL
FASTENERS . . . . . . . . . . . . . . . . . . . . . . . . .STAINLESS STEEL
Model 350U
MAX PRESSURE . . . . . . . . . . . . . . . . . . . . . . . . . TO 1200 PSI
OPEN FLOW . . . . . . . . . . . . . . . . . . . . . . . . . . . . TO 3.7 GPM
SEALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U-CUP
O-RINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VITON/BUNA
INLET PORTS (2) . . . . . . . . . . . . . . . . . . . . . . . . . .3/8” F NPT
DISCHARGE PORTS (2) . . . . . . . . . . . . . . . . . . . . 3/8” F NPT
MAX FLUID TEMP . . . . . . . . . . . . . . . . . . . . . . . . . . TO 140˚F
MATERIALS OF CONSTRUCTION
BODY . . . . . . . . . . . . . . . . . . . . . . . . ANODIZED ALUMINUM
PLUNGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 SS
VALVES . . . . . . . . . . . . . . . . . . . . . . . . . . . .STAINLESS STEEL
FASTENERS . . . . . . . . . . . . . . . . . . . . . . . . .STAINLESS STEEL
GENERAL SAFETY INFORMATION
Please read this manual before installing or operating pump to
provide safe operation and prevent equipment problems.
Observe the following symbols and definitions.
Note: Indicates important instructions which are not related to
hazards.
IMPORTANT: Indicates factors concerned with assembly,
installation, operation, or maintenance which could result in
damage to the machine or equipment if ignored.
Warns about hazards that MAY cause
minor personal injury or property damage if ignored.
Warns about hazards that COULD cause
serious personal injury, death or major property damage if
ignored.
Warns about hazards that WILL cause
serious person injury, death or major property damage if
ignored.
___________________________________________
PLEASE READ, SAVE AND REFER TO SAFETY
INSTRUCTIONS BELOW:
Pumps build up heat and pressure during
operation. Allow time for pumps to cool before handling or
servicing. Only qualified personnel should install, operate, and
repair pump.
IMPORTANT: For pumping liquids other than water, contact
your supplier.
Do not pump hazardous materials
(flammable, caustic, etc.), unless the pump is specifically
designed and designated to handle them.
To reduce risk of electric shock, always
disconnect pump from power source before handling or
servicing.
Any wiring of pumps should be performed
by a qualified electrician.
These pumps are not intended to be
submersed.
Pumptec, Inc. is not responsible for losses, injury, or death
resulting from a failure to observe these safety precautions,
misuse or abuse of pumps or equipment.
CAUTION!
WARNING!
DANGER!
CAUTION!
DANGER!
WARNING!
WARNING!
CAUTION!

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
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INSTALLATION
MOUNTING
Pump motor set can be mounted in any position EXCEPT with
pump head higher than motor. To minimize amp draw, noise,
and vibration, use appropriate flexible hose to inlet and
discharge ports.
LOCATION
If the pump is used in extremely dirty or
humid conditions, it is recommended that the pump be
enclosed. Do not store or operate in excessively high
temperature areas or without proper ventilation.
The pumping system can be mounted where it is visible, but it
must be protected from rain, dirt and chemical spray or
splashing. The pump must never be installed on a vertical
surface with the pump head higher than motor, like a capital
letter “T”, for example.
PRE-OPERATION
INLET CONDITIONS
DO NOT STARVE THE PUMP OR RUN DRY.
Temperatures above 130°F will require a pressurized inlet to
avoid cavitation and seal damage.
DISCHARGE CONDITIONS
Open all valves in system prior to operation to avoid excessive
load on motor and system from a pressure spike. Follow the
instructions of proper system design. Refer to supplier if
assistance is needed.
PRESSURE REGULATION
Verify pressure regulation devices are operating correctly.
NOZZLES
Nozzles create pressure in most systems, and the nozzle size
becomes larger with use. Larger nozzles decrease system
pressure. Verify the quality of nozzles prior to operation.
MOTOR SHAFT ROTATION
Motor shaft rotation must always be
counterclockwise to assure proper function of pump otherwise
the warranty may be void.
PUMPED LIQUIDS
Some liquids may require a flush between operations or before
storing. For pumping liquids other than water, contact your
supplier.
OPERATION
GENERAL OPERATING INFORMATION
Pressure is often created by forcing a volume of fluid (flow)
through a specific size hole (nozzle). Additionally, pressure can
be created by pumping into a non-expanding chamber. Pressure
is measured and stated in pounds per square inch or PSI.
Flow is created based upon the pump displacement and speed
(RPM) of the motor. Pump plunger size affects flow based upon
the same RPM. The faster the motor speed, the greater the
flow. Flow is measured and stated in gallons per minute or GPM.
The pump, driven by a motor or engine, draws fluid through a
set of valves into the pumping chamber and the fluid is then
forced out of a set of valves to exit the pump. The back-and-
forth movement of the plunger in the sealed pumping chamber
creates the suction and discharge actions.
Once the fluid has exited the pump it must be controlled until
it exits the nozzle or reaches the place it needs to go. This
control is achieved via the use of system components such as
an unloader or regulator. Theses pumps are positive
displacement pumps, which provide a specific amount of fluid
constantly while operating. This volume of fluid must be
directed out thru a nozzle or back to a tank because it cannot
be stopped completely without creating excessively high
pressure and risk of damage to the pump, components,
property, or person. It is recommended a safety device such
as a regulating valve (regulator) be installed directly on the
pump head as protection in case of the failure of another
component. Pressure switches can be used to automate pump
operation, but they must have a pressure regulating device
installed as a safety device.
Fluid can enter a pump either from a filtered tank or pressurized
fluid line.
It is common to use a tank with pumps that are mounted above
the pump. Filtration is important to maintain proper function of
the pump and system. The extent of filtration may be more
extensive based upon the application of the pump such as
misting with ultra-fine nozzles.
INLET CONDITION CHECKLIST
Inadequate inlet conditions can cause serious malfunctions
even in the best designed pumps. Surprisingly, the simplest
things can cause the most severe problems or go unnoticed to
CAUTION!
CAUTION!
CAUTION!

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the unfamiliar or untrained eye. REVIEW THIS CHECKLIST
BEFORE OPERATION OF ANY SYSTEM. Remember, no two
systems are alike so there can be no ONE best way to setup a
system. All factors must be carefully considered.
INLET SUPPLY should exceed the maximum flow being
delivered by the pump to assure proper performance.
•Open inlet shut-off valve and turn on water supply to avoid
starving the pump. DO NOT RUN PUMP DRY.
•Avoid closed loop systems especially with high temperature,
ultra-high pressure, or large flows. Conditions vary with
regulating/unloader valve.
•When using an inlet supply reservoir, size it to provide
adequate liquid to accommodate the maximum output of the
pump, generally a minimum of 6-10 times the GPM. However,
a combination of system factors can change this requirement.
INLET LINE SIZE should be adequate to avoid starving the
pump.
•Line size must be a minimum of one size larger than the pump
inlet fitting. Avoid tees, 90-degree elbows, or valves in the
inlet line of the pump to reduce the risk of flow restriction and
CAVITATION.
•The line MUST be a FLEXIBLE hose, NOT a rigid pipe, and
reinforced on SUCTION systems to avoid collapsing.
•The simpler the inlet plumbing the less potential for
problems. Keep the length to a minimum, the number of
elbows and joints to a minimum (ideally no elbows) and the
inlet accessories to a minimum.
•Use pipe sealant to assure airtight, positive sealing pipe joints.
INLET PRESSURE should fall within the specifications of the
pump.
•High RPM, high temperatures, low vapor pressures or high
viscosity may increase acceleration loss of liquids.
•Optimum pump performance is obtained with +20 PSI (1.4
BAR) inlet pressure. With adequate inlet plumbing, most
pumps will perform with flooded suction.
•After prolonged storage, the pump should be purged of air to
facilitate priming. Disconnect the discharge port to allow
liquid to pass through pump and measure flow.
BYPASS TO INLET –care should be exercised when deciding
the method of bypass from control valves. See Misting on pages
4 and 5.
•It is recommended that the bypass be directed to a baffled
reservoir tank, with at least one baffle between the bypass
line and the inlet line to the pump.
•Although not recommended, bypass liquid may be returned
to the inlet line of the pump if the system is properly designed
to protect your pump.
•A low-pressure, flexible hose should be used from the bypass
connection to the inlet of the pump.
•Caution should be exercised to avoid under sizing the bypass
hose diameter and length.
•Check the pressure in the bypass line to avoid over-
pressurizing.
USING CHEMICALS
Chemicals can be mixed into the fluid, and it is necessary to
understand whether these chemicals will damage the pump or
other system components. Another way to put chemicals into
the fluid is with a downstream injector.
An injector works as a result of the difference in pressure
between the inlet side of injector and discharge side. In most
cases, the pressure on the discharge side cannot exceed 1/2 of
the inlet pressure. For example, 1000 PSI into an injector should
allow up to 500-600 PSI spray pressure on discharge side. There
are dual-function nozzles that permit high pressure, chemical
free rinse and low pressure, chemical spray. These are
convenient for the operator and will not harm a properly
designed system. The advantages of an injector are:
-Fewer items come in contact with chemical
-Chemical injection rate can be controlled
-Applying chemicals at lower pressure increases chemical
use efficiency
HEATING FLUID
Pumps may sometimes be used with downstream heaters and
precautions need to be taken to protect the system and
persons from harm. Refer to the skilled staff at the equipment
manufacturer for guidance and proper system care. Please be
aware that heated water expands, and additional pressure
release safety devices may be required.
SYSTEM DESIGN
A pump is the heart of every system and proper selection is
critical to equipment functionality and durability. If a
pumping set with excess flow is chosen, then energy and fluid
is wasted. If excess pressure results, then equipment
effectiveness can decrease as well as pump life.

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TYPICAL APPLICATIONS AND THEIR PERFORMANCE
CONSIDERATIONS
PRESSURE CLEANING
The optimal combination of PSI and GPM for cleaning is a ratio
of 1 GPM for every 300-400 PSI. This combination maintains
sufficient droplet size for cleaning force and distance. If
pressure increases, and flow does not, then the water droplet
size reduces and has less impact force, requiring closer cleaning
distances and increased risk of surface damage.
PEST SPRAYING
This application can have specific chemical usage requirements
and application pressure limits, so use the included information
as a guide only. Refer to label requirements for each specific
chemical.
LINE LOSS
When choosing a pump for spraying, pressure loss in the hose
must be considered. The pressure is greatest at the pump and
decreases over the length of the hose. Typically, these systems
utilize very long hoses, 200-300 ft. is common, and requires a
certain minimum amount of performance to move the flow
through the lengths of hose. For example, a 3 GPM system will
require (lose) 50 PSI per 50 ft. of 3/8” ID hose. A pump with only
60-70 PSI may not provide the desired performance at the end
of the hose. See reference charts to assist in system design.
MISTING
It is critical to size the pump correctly in a misting application. If
insufficient flow is chosen, then proper atomization and droplet
size will not be possible. If excessive flow is chosen, then
unnecessary wear and wasted energy will occur in this very
demanding application.
Another consideration for misting is regarding the routing of the
bypass fluid. DO NOT return bypass fluid from regulating valve
directly back to inlet of pump. The returned fluid will contain
large amounts of air bubbles that will cause cavitation and
damage in the pump head. Also, the small amount of returned
fluid can heat up rapidly and lead to further cavitation and
component damage. It is recommended to route bypass back to
inlet of filter to allow air bubbles to dissolve and water to cool
prior to entering pump.
Please use the following charts as a guide to understand the
basic system requirements.
NOTE: Nozzle sizes in the performance chart are additive. For
example, 2 pieces of ’02 nozzle equals the performance of 1
piece of ’04.
Nozzles create restriction (pressure) in the system. If unsure of
the nozzle size needed for desired performance, refer to the
nozzle Performance Chart. If you are sure of your nozzle size,
but unsure of which pump set to choose, then use the Nozzle
Performance Chart (below) along with the Horsepower Chart
on our website to determine your required pump specification.
Here is an example of how to use these charts together: when
you have 2 pieces of an ’02 nozzle and you want 500 PSI, the
nozzle chart will tell you that 2 pieces of an ’02 nozzle has a flow
equal to 1 piece of an ’04 nozzle. At 500 PSI, an ’04 nozzle has a
flow of 1.4 GPM. The performance specification is 1.4 GPM at
500 PSI.
The Horsepower Chart indicates that 1.4 GPM at 500 PSI
requires .408 HP. You will need to select a pump set that can
perform at this level. Refer to page 6.
STORING
For extended storage periods or between uses in cold climates,
drain all pumped liquids from pump and flush with antifreeze
solution to prevent freezing and damage to the pump. DO NOT
RUN PUMP WITH FROZEN LIQUID.
NOTE: Each system’s maintenance cycle will be unique. If
system performance decreases, check immediately. If there is
no wear at 500 hours, check again at 1000 hours and each 500
hours until wear is observed. Valves typically require changing
every seal change. Duty cycle, temperature, quality of pumped
liquid and inlet feed conditions all affect the life of a pump’s
parts and service cycle.
NOTE: Remember to service the regulator/unloader at each
seal servicing and check all system accessories and connections
before resuming operation.

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Version 100522
NOZZLE PERFORMANCE CHART
40
PSI
100
PSI
250
PSI
500
PSI
600
PSI
700
PSI
800
PSI
1000
PSI
1200
PSI
NOZZLE
SIZE
ORIFICE
DIA.
THEORETICAL DISCHARGE VOLUME (GPM)
2
0.034
0.20
0.32
0.50
0.71
0.77
0.84
0.89
1.00
1.10
2.5
0.039
0.25
0.40
0.63
0.88
0.97
1.05
1.12
1.25
1.37
3
0.043
0.30
0.47
0.75
1.03
1.16
1.25
1.34
1.50
1.64
3.5
0.048
0.35
0.55
0.88
1.24
1.36
1.46
1.57
1.75
1.92
4
0.052
0.40
0.63
1.00
1.41
1.55
1.67
1.79
2.00
2.19
4.5
0.055
0.445
0.71
1.13
1.59
1.74
1.88
2.01
2.25
2.46
5
0.057
0.50
0.79
1.25
1.77
1.94
2.09
2.24
2.50
2.74
5.5
0.060
0.55
0.87
1.38
1.94
2.13
2.30
2.46
2.75
3.01
6
0.062
0.60
0.95
1.50
2.12
2.32
2.51
2.68
3.00
3.29
6.5
0.064
0.65
1.03
1.63
2.30
2.52
2.72
2.91
3.25
3.56
7
0.067
0.70
1.11
1.75
2.47
2.71
2.93
3.13
3.50
3.83

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
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MAINTENANCE
DISASSEMBLY AND REASSEMBLY
INSTRUCTIONS (350U VIDEO)
1. Remove the pump from the motor. Remove bolts at each
end of pump. Turn pump over so manifold is facing upward.
Place manifold to side as a reference for reassembly.
Figure 1
2. Holding each head, pull them apart to remove plunger.
Remove retaining plate from pump head. Remove internal
seal parts with finger. Discard parts, keeping the head and
retainer plate.
Figure 2
3. Clean the head with a rag or towel inspect for damage or
excess corrosion. If the head is damaged, do not rebuild.
4. Place one 024 o-ring, u-cup, and support ring into bore.
Verify that support ring is flush with top of u-cup. Place 124
o-ring (largest o-ring) into recessed area around top of
bore. Lightly grease second 024 o-ring and place around
plunger guide. Press plunger guide with o-ring installed into
bore. See Figure 3.
Figure 3
5. Lightly grease 117 o-ring and place in retainer plate pocket.
Place and press seal ring evenly within o-ring. Be careful to
apply even pressure and eliminate bulges in o-ring. Slide
retainer plate/o-ring/seal ring combo into pump head. If
any piece dislodges, do not continue to slide plate, but re-
adjust before sliding plate into place completely.
Figure 4
Figure 5
6. Repeat the previous steps 4 and 5 with the other head.

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
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Version 100522
7. Lightly grease the plunger with provided grease. Slide
plunger into one head and then slide other head onto
plunger. Place head and plunger assembly on work surface
with valves facing upward.
Figure 6
8. Adjust plunger slot position towards center and have slot
facing work surface. Replace all valves, o-rings, and white
washers. Refer to image and manifold label to understand
proper orientation. Outlets are nearest the sticker side.
Figure 7
Figure 8
9. Place manifold on top heads. It may be necessary to shift
heads around on plunger to have valves align with valve
pockets on manifold. Be careful to not lose the white
washers in the manifold during reassembly. See Fig. 9.
IMPORTANT: It is imperative the alignment of OUT/IN
ports coincide with valves as indicated in Figure 7 and 8.
Figure 9
10. Turn assembly over and place bolt and washer assembly
into heads and tighten finger tight. DO NOT tighten
completely at this time. See Fig. 9.
11. Apply remaining grease from included packet into corners
and center of plunger slot as shown in Figure 9.
Figure 10

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
Version 100522
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PREVENTIVE MAINTENANCE CHECKLIST
Check
Daily
Weekly
50 Hrs.
500 Hrs.
1500 Hrs.
3000 Hrs.
Clean Filters
X
Water leaks
X
Descale Pump
X
X
Cam & bearing
X
X
Seal Change
X
X
Valve Change
X
X
TROUBLESHOOTING CHART
SYMPTOM
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
No water flow
1. Tank is empty, or water is not turned on
1. Fill tank or turn on water supply
2. Filter is clogged
2. Clean filter
3. Pump valves are clogged or damaged
3. Examine valves and clean or replace
4. Pump has lost prime
4. Follow priming procedure
Low pressure
1. Worn nozzle
1. Replace nozzle with new one of same size
2. Leak in high pressure hose or connections
2. Check hose and connections
3. Filter is clogged
3. Clean filter
4. Pump valves are clogged or damaged
4. Examine valves and clean or replace
Pump pulsates when spraying
1. Filter is clogged
1. Clean filter
2. Pump valves are clogged or damaged
2. Examine valves and clean or replace
Motor does not operate
1. Blown fuse or circuit breaker
1. Replace circuit breaker or fuse. Check circuit
for wire damage or component damage
Leaks seen under pump
1. Worn pump seals
1. Replace with new plunger and seals
2. Abrasives in solution have damaged pump seals
2. Mix chemical thoroughly and improve filter
Regulator leaks fluid from cap
1. Pressure is set too low
1. Set pressure higher to keep internals from
moving too much
2. Replace seal
For Repair Parts, call 763-433-0303
Please provide following information:
- Model number
- Serial number (if any)
- Part description and number as shown in parts list

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
Version 100522
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Repair Parts Illustration for Plunger Pump
REPAIR PARTS LIST FOR PLUNGER PUMP
DESCRIPTION
PART NO.
QTY
DESCRIPTION
PART NO.
QTY
KIT A, 348U/350U
10013
KIT B
10004
Plunger
^
1
White Washer, ½” ID
^
8
O-Ring, 1-117
^
2
O-Ring, 1-116
^
4
Seal Ring, 1-124
^
2
Valve Assembly
^
4
Plunger Guide
^
2
Retainer Plate
*
2
Support Ring, 1-116
^
4
Pump Head
*
2
U-Cup
^
2
Pump Manifold
*
1
O-Ring, 1-024
^
4
(^) Sold only as part of a kit. | (*) Not part of a kit, for identification only.

Pumptec Operating Instructions and Parts Manual PUMP SERIES 348U | 350U
Version 100522
11
ADDITIONAL RESOURCES
Pumptec Returns Authorization Request Form
Warranty Policy
Prompt Disposition A good faith effort will be made for prompt correction or other adjustment with respect to any product which proves
to be defective within limited warranty. For any product believed to be defective within limited warranty, first visit Pumptec's website,
email, or call Pumptec. Pumptec will give additional directions. If unable to resolve satisfactorily, write to Pumptec at the address below,
giving the serial number, invoice number and date, and describing the nature of the defect. Title and risk of loss pass to buyer on delivery
to common carrier. If product was damaged in transit to you, file claim with carrier.
Manufactured by Pumptec, Inc. 700 McKinley St. NW, Anoka, Minnesota 55303 U.S.A.
Phone: [phone]