Nordson StediFlo 57:1 Reference guide

StediFlotHigh Pressure
57:1 Pump
Customer Product Manual
Part 1601882-01
Issued 7/12
NORDSON CORPORATION •AMHERST, OHIO •USA
Check http://emanuals.nordson.com/finishing for the latest version.
This document is subject to change without notice.
For parts and technical support, call the Industrial
Coating Systems Customer Support Center at [phone]

Part 1601882-01 E2012 Nordson Corporation
Table of Contents
Safety 1.......................................
Qualified Personnel 1.........................
Intended Use 1..............................
Regulations and Approvals 1..................
Personal Safety 2............................
High-Pressure Fluids 2.....................
Fire Safety 3................................
Halogenated Hydrocarbon Solvent Hazards 4.
Action in the Event of a Malfunction 4...........
Disposal 4..................................
Description 5..................................
Specifications 6..............................
Dimensions 7.............................
Installation 8..................................
Dead-End System Diagram 8..................
Circulating System Diagram 9.................
Mounting 9..................................
Connections 10...............................
Air Supply Connections 10...................
Hydraulic Connections 10...................
Grounding 10.................................
Solvent Fluid 10..............................
Air Lubricator Oil 11...........................
Operation 11...................................
Checking the System 11.......................
Filling the Solvent Chamber 11.................
Adjusting the Air Lubricator 11..................
Flushing 12..................................
Daily Operation 12............................
Changing Colors or Material 13.................
Shutdown 14.................................
Maintenance 14................................
Daily 14.....................................
As Needed Maintenance 15....................
Troubleshooting 15.............................
General Troubleshooting 15....................
Air Motor Troubleshooting 18...................
Hydraulic Section Repair 19.....................
Preparation 19................................
Air Motor / Hydraulic Section Separation 20.......
Hydraulic Section Disassembly 20...............
Siphon Ball Check Disassembly 20..............
Pressure Ball Check Disassembly 20............
Cleaning and Inspection 21.....................
Pressure Ball Check Assembly 21...............
Siphon Ball Check Assembly 21................
Lower Packing Gland Assembly 21..............
Upper Packing Gland Assembly 22..............
Hydraulic Section Assembly 22.................
Air Motor Repair 23.............................
Tools and Materials Required 23
................
Preparation 23................................
Upper Control Housing Removal 24.............
Control Housing Removal 24...................
Control Cylinder Removal 24...................
Toggle Assembly Removal 24..................
Lower Control Housing Removal 25.............
Control Axle Removal 25.......................
Upper Cylinder Plate Removal 25...............
Cylinder and Piston Removal 26................
Piston Disassembly 26........................
Lower Cylinder Plate Disassembly 26............
Cleaning and Inspection 26.....................
Lower Cylinder Plate Assembly 26..............
Piston Assembly 27...........................
Cylinder Assembly 28.........................
Upper Cylinder Plate Assembly 28..............
Control Axle Assembly 29......................
Lower Control Housing Assembly 29............
Toggle Assembly Installation 30.................
Control Cylinder Assembly 30..................
Lower Control Housing Installation 31............
Upper Control Housing Installation 31............
Parts Information 32............................
Pump Part Numbers 32........................
Hydraulic Section Parts List 32..................
Air Motor Parts List 34.........................
Options 36...................................
Declaration of Conformity
Contact Us
Nordson Corporation welcomes requests for information, comments, and
inquiries about its products. General information about Nordson can be
found on the Internet using the following address:
http://www.nordson.com.
Address all correspondence to:
Nordson Corporation
Attn: Customer Service
555 Jackson Street
Amherst, OH 44001
Notice
This is a Nordson Corporation publication which is protected by copyright.
Original copyright date 2012. No part of this document may be
photocopied, reproduced, or translated to another language without the
prior written consent of Nordson Corporation. The information contained
in this publication is subject to change without notice.
Trademarks
Nordson and the Nordson logo are registered trademarks of Nordson
Corporation.
StediFlo is a trademark of Nordson Corporation.
All other trademarks are the property of their respective owners.

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StediFlot57:1 Pump
Safety
Read and follow these safety instructions. Task- and equipment-specific
warnings, cautions, and instructions are included in equipment
documentation where appropriate.
Make sure all equipment documentation, including these instructions, is
accessible to persons operating or servicing equipment.
Qualified Personnel
Equipment owners are responsible for making sure that Nordson equipment
is installed, operated, and serviced by qualified personnel. Qualified
personnel are those employees or contractors who are trained to safely
perform their assigned tasks. They are familiar with all relevant safety rules
and regulations and are physically capable of performing their assigned
tasks.
Intended Use
Use of Nordson equipment in ways other than those described in the
documentation supplied with the equipment may result in injury to persons
or damage to property.
Some examples of unintended use of equipment include
Susing incompatible materials
Smaking unauthorized modifications
Sremoving or bypassing safety guards or interlocks
Susing incompatible or damaged parts
Susing unapproved auxiliary equipment
Soperating equipment in excess of maximum ratings
Regulations and Approvals
Make sure all equipment is rated and approved for the environment in which
it is used. Any approvals obtained for Nordson equipment will be voided if
instructions for installation, operation, and service are not followed.

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Personal Safety
To prevent injury follow these instructions.
SDo not operate or service equipment unless you are qualified.
SDo not operate equipment unless safety guards, doors, or covers are
intact and automatic interlocks are operating properly. Do not bypass or
disarm any safety devices.
SKeep clear of moving equipment. Before adjusting or servicing moving
equipment, shut off the power supply and wait until the equipment
comes to a complete stop. Lock out power and secure the equipment to
prevent unexpected movement.
SRelieve (bleed off) hydraulic and pneumatic pressure before adjusting or
servicing pressurized systems or components. Disconnect, lock out,
and tag switches before servicing electrical equipment.
SWhile operating manual spray guns, make sure you are grounded.
Wear electrically conductive gloves or a grounding strap connected to
the gun handle or other true earth ground. Do not wear or carry metallic
objects such as jewelry or tools.
SIf you receive even a slight electrical shock, shut down all electrical or
electrostatic equipment immediately. Do not restart the equipment until
the problem has been identified and corrected.
SObtain and read Material Safety Data Sheets (MSDS) for all materials
used. Follow the manufacturer’s instructions for safe handling and use
of materials, and use recommended personal protection devices.
SMake sure the spray area is adequately ventilated.
STo prevent injury, be aware of less-obvious dangers in the workplace
that often cannot be completely eliminated, such as hot surfaces, sharp
edges, energized electrical circuits, and moving parts that cannot be
enclosed or otherwise guarded for practical reasons.
High-Pressure Fluids
High-pressure fluids, unless they are safely contained, are extremely
hazardous. Always relieve fluid pressure before adjusting or servicing high
pressure equipment. A jet of high-pressure fluid can cut like a knife and
cause serious bodily injury, amputation, or death. Fluids penetrating the
skin can also cause toxic poisoning.
If you suffer a fluid injection injury, seek medical care immediately. If
possible, provide a copy of the MSDS for the injected fluid to the health care
provider.
The National Spray Equipment Manufacturers Association has created a
wallet card that you should carry when you are operating high-pressure
spray equipment. These cards are supplied with your equipment. The
following is the text of this card:

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WARNING: Any injury caused by high pressure liquid can be serious. If
you are injured or even suspect an injury:
SGo to an emergency room immediately.
STell the doctor that you suspect an injection injury.
SShow him this card
STell him what kind of material you were spraying
MEDICAL ALERT—AIRLESS SPRAY WOUNDS: NOTE TO PHYSICIAN
Injection in the skin is a serious traumatic injury. It is important to treat the
injury surgically as soon as possible. Do not delay treatment to research
toxicity. Toxicity is a concern with some exotic coatings injected directly into
the bloodstream.
Consultation with a plastic surgeon or a reconstructive hand surgeon may
be advisable.
The seriousness of the wound depends on where the injury is on the body,
whether the substance hit something on its way in and deflected causing
more damage, and many other variables including skin microflora residing
in the paint or gun which are blasted into the wound. If the injected paint
contains acrylic latex and titanium dioxide that damage the tissue’s
resistance to infection, bacterial growth will flourish. The treatment that
doctors recommend for an injection injury to the hand includes immediate
decompression of the closed vascular compartments of the hand to release
the underlying tissue distended by the injected paint, judicious wound
debridement, and immediate antibiotic treatment.
Fire Safety
To avoid a fire or explosion, follow these instructions.
SGround all conductive equipment. Use only grounded air and fluid
hoses. Check equipment and workpiece grounding devices regularly.
Resistance to ground must not exceed one megohm.
SShut down all equipment immediately if you notice static sparking or
arcing. Do not restart the equipment until the cause has been identified
and corrected.
SDo not smoke, weld, grind, or use open flames where flammable
materials are being used or stored.
SDo not heat materials to temperatures above those recommended by
the manufacturer. Make sure heat monitoring and limiting devices are
working properly.
SProvide adequate ventilation to prevent dangerous concentrations of
volatile particles or vapors. Refer to local codes or your material MSDS
for guidance.
SDo not disconnect live electrical circuits when working with flammable
materials. Shut off power at a disconnect switch first to prevent
sparking.

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Fire Safety (contd)
SKnow where emergency stop buttons, shutoff valves, and fire
extinguishers are located. If a fire starts in a spray booth, immediately
shut off the spray system and exhaust fans.
SShut off electrostatic power and ground the charging system before
adjusting, cleaning, or repairing electrostatic equipment.
SClean, maintain, test, and repair equipment according to the instructions
in your equipment documentation.
SUse only replacement parts that are designed for use with original
equipment. Contact your Nordson representative for parts information
and advice.
Halogenated Hydrocarbon Solvent Hazards
Do not use halogenated hydrocarbon solvents in a pressurized system that
contains aluminum components. Under pressure, these solvents can react
with aluminum and explode, causing injury, death, or property damage.
Halogenated hydrocarbon solvents contain one or more of the following
elements:
Element Symbol Prefix
Fluorine F “Fluoro-”
Chlorine Cl “Chloro-”
Bromine Br “Bromo-”
Iodine I “Iodo-”
Check your material MSDS or contact your material supplier for more
information. If you must use halogenated hydrocarbon solvents, contact
your Nordson representative for information about compatible Nordson
components.
Action in the Event of a Malfunction
If a system or any equipment in a system malfunctions, shut off the system
immediately and perform the following steps:
SDisconnect and lock out system electrical power. Close hydraulic and
pneumatic shutoff valves and relieve pressures.
SIdentify the reason for the malfunction and correct it before restarting the
system.
Disposal
Dispose of equipment and materials used in operation and servicing
according to local codes.

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Description
The StediFlo 57:1 fluid pump is an air-operated, stainless steel pump
suitable for solvent-based and waterborne coatings. It is a double-acting
pump that delivers pressurized coatings on both the pressure and suction
strokes. Coatings are siphoned into the pump only on the suction stroke.
The pump can be used in both dead-end and circulating systems. In
dead-end systems, the pump stops when the pressure in the system equals
the pressure the pump can output given the input pressure. In circulating
systems, the pump strokes continuously to keep coating material moving
through the system at a rate set by the circulation valve.
Two sets of self-adjusting packings prevent coatings from leaking from the
pump during operation. The upper packings and plunger are lubricated by
solvent fluid in the solvent chamber. The lower packings are lubricated by
the coating material in the pump.
Filtered and lubricated compressed air operates the air motor and air value.
A safety relief valve in the air motor head prevents over-pressurization.
Air Filter/Regulator/Gauge
Siphon Inlet
Fluid Outlet/Check Valve
Air Motor
Hydraulic Section
Siphon Rod/
Strainer
Siphon Hose
Air Lubricator
Mufflers
Shutoff Valve
Solvent Fluid Drain/Fill
Solvent Chamber
1 in. NPT
Figure 1 StediFlo 57:1 Pump Components

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Specifications
Specification Metric English
Weight 100 kg 220 lb
Maximum air input pressure 7 bar 101 psi
Approximate air consumption
(per cycle at 1 bar / 15 psi)
0.34 l/min. 0.012 ft3/min.
Air motor piston diameter 333 mm 13 in
Air motor piston stroke length 120 mm 4.7 in.
Maximum operating pressure
(fluid output)
399 bar 5787 psi
Output per cycle 360 cm312.2 oz.
Air inlet size 1/2 in. G female
Fluid outlet size 1 in. NPT male
Sound pressure levels:
At idle 84 (LpAd) (dB)
Running with load 80 (LpAd) (dB)
ATEX Marking Ex II 2G cT4
WARNING: Do not operate the pump at a higher operating pressure than
the lowest maximum operating pressure of any component in the system.
Failure to observe this warning could result in equipment damage or
personal injury.

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Dimensions
Solvent Chamber Filler
Solvent Chamber Drain
∅13 (4X)
218
160
1383
1246
651
595
202
300
446
Figure 2 StediFlo 57:1 Pump Dimensions

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Installation
WARNING: Allow only qualified personnel to perform the following tasks.
Follow the safety instructions in this document and all other related
documentation.
NOTE: The pump and system must be flushed before beginning regular
operation. Refer to Flushing on page 12.
Dead-End System Diagram
1
2
3
4
5
6
8
9
10
12
11
10
7
13
Figure 3 Typical Dead-End System Configuration
1. Plant air line
2. Drop leg
3. Drain valve
4. Air shut off valve (self-relieving)
5. Filter/Regulator/Lubricator
6. Air hose
7. Coating supply
8. Siphon rod and strainer
9. Siphon hose
10. High-pressure fluid hose
11. Fluid filter
12. Spray gun
13. Drain valve

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Circulating System Diagram
1
2
3
4
5
6
8
9
10
14 11
10
13
10
15
16
18
7
17
12
Figure 4 Typical Circulation System Configuration
1. Plant air line
2. Drop leg
3. Drain valve
4. Air shut off valve (self-relieving)
5. Filter/Regulator/Gauge
6. Air hose
7. Coating supply
8. Siphon rod and strainer
9. Siphon hose
10. High-pressure fluid hose
11. Fluid filter
12. Filter drain valve
13. Spray gun
14. Fluid heater
15. Circulation valve
16. Drain valve
17. Drain hose and rod
18. Waste container
Note: To install the optional circulation valve kit, refer to the instructions included with the kit.
Mounting
If the pump is mounted on a cart, make sure the cart is parked on a level
and solid surface. Leave space around the cart to work.
If mounting the pump on a wall or fixed stand, use M12 screws, class 8.8.
Mount the pump so that at least 10 cm (4 in.) of free space is left between
the floor and the suction fitting. Refer to Options in the Parts section for an
optional wall mounting bracket.

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Connections
Air Supply Connections
Connect the air regulator gauge to the air motor inlet (1 in. G), either directly
or by way of an appropriate hose, which should be at least the same size as
the air inlet fitting. If the air supply to the pump is hard-plumbed, install a
short air hose in the line ahead of the air motor or regulator to serve as a
vibration damper.
Hydraulic Connections
NOTE: Use hydraulic pipe thread sealant/adhesive where required.
1. Connect the siphon hose and strainer to the suction fitting. The
connections must be air-tight to prevent the pump from siphoning air.
2. Connect an appropriate high pressure hose to the check valve
(1-in. NPT threads) at the fluid outlet and route it to the fluid filter or fluid
heater.
NOTE: Fluid heaters can only be used in circulating systems. The fluid
filter must be installed between the heater and the spray gun.
Grounding
WARNING: The high flow of fluid through the pump can create a
dangerous static electricity charge. Sparks caused by a static discharge
can cause a fire or explosion. The pump and all conductive equipment in
the spray area must be grounded. All hoses must be conductive.
Connect the ground cable shipped with the pump to the pump; connect the
opposite end to a true earth ground.
Solvent Fluid
Before using the pump for the first time, remove the “Peel off before use”
label and remove the plug from the vent elbow in the air motor base. This
vents the solvent chamber.
Vent
Filler
Figure 5 Vent Elbow
See Figure 2. Remove the fill cap on the tee and fill the solvent chamber
with approved solvent fluid until the fluid is visible approximately 1 cm (0.4
in.) below the fill opening. The chamber holds approximately 50 ml
(1.7 fl. oz).

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Air Lubricator Oil
Remove the air lubricator fill cap and fill the lubricator with oil. The
maximum oil level is indicated by a line on the reservoir. When you start the
pump, run it at a slow speed and adjust the lubricator to deliver one drop of
oil for every 10−15 cycles of the pump.
NOTE: If high humidity causes icing of the air motor, you can replace the
lubricator oil with a pure anti-freeze solution, or heat the air supply. In all
cases, the air supply should be clean and dry.
Operation
WARNING: Allow only qualified personnel to perform the following tasks.
Follow the safety instructions in this document and all other related
documentation.
WARNING: The spray area must be adequately ventilated according to
local regulations. The operator should wear appropriate protective
breathing equipment at all times when spraying.
WARNING: All conductive equipment in the spray area must be connected
to a true earth ground. Inspect all ground connections regularly.
Checking the System
Before starting the pump, make sure
Sthe system components (such as the heater and filter) have been
installed according to the instructions in their manuals.
Sall fluid and air fittings and connections are tightened securely.
Sthe air shutoff valve and the circulation and drain valves (if used) are
closed and the air regulator is set to zero pressure.
Filling the Solvent Chamber
See Figure 2. Remove the fill cap and fill the solvent chamber with solvent
fluid until fluid is visible approximately 1 cm (0.4 in.) below the vent opening.
The chamber holds approximately 50 ml (1.7 fl oz).
Adjusting the Air Lubricator
Adjust the lubricator to deliver one drop of oil for every 10−15 cycles of the
pump. Fill the lubricator daily before starting production. The maximum oil
level is indicated by a line on the reservoir. If high humidity causes icing of
the air motor, fill the lubricator with pure anti-freeze solution, or heat the air.

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Flushing
Before starting production, a new pump and spray system must be flushed
with a solvent or waterborne cleaning solution compatible with the coating
material you are using. This ensures that all oils and contaminants left
during the manufacturing and installation process are flushed out of the
system.
NOTE: Turn off the fluid heater (If used) before flushing the system.
Requirements:
SFlushing solvent or waterborne cleaning solution
SCoating material
SGrounded waste container
1. Place the suction strainer in the flushing material, or supply it through a
pressure feed system.
2. Place the waste container under the filter or circulation drain valve, then
open the valve.
3. Start the pump and adjust the input air pressure to 2 bar (30 psi).
4. Run the pump until flushing material flows from the filter drain valve,
then close it.
NOTE: If using a circulating system, a drain valve should be connected
to the circulation valve. Place a ground waste container under this valve
and open it after closing the filter drain valve. When flushing material
flows from this valve, close it.
5. Ground the manual spray gun against the side of the waste container
and spray into the container for at least 1 minute. If using automatic
guns, turn them on and spray into the spray booth.
6. Shut off the spray gun.
7. Increase the air pressure to the maximum allowable (7 bar, 101 psi).
Check all system connections and seals: hoses, gun, heater, filter. If
leaks are present anywhere, stop the pump, relieve the fluid pressure,
and fix the leak.
8. Increase the air pressure to approximately 10% above the maximum
pressure. The pressure relief valve on the air motor should open. This
ensures that the valve works properly.
9. Adjust the air pressure so that when the spray gun is triggered the pump
runs very slowly. Remove the siphon strainer from the solvent, then
trigger the gun to flush the remaining solvent out of the system.
10. Stop the pump and shut off the pump air.
11. Open the drain valves to relieve the pressure and drain any remaining
solvent from the system.
Daily Operation
1. Check the solvent chamber level and fill if necessary.
2. Place the siphon strainer into a container of coating material, or supply
coating material to the pump through a pressure feed system.

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3. Adjust the pump air pressure to 2 bar (30 psi) so that it is running slowly.
4. Place a waste container under the filter drain valve and open the valve.
Close the valve when coating material starts to flow into the waste
container.
5. Ground the spray gun against the side of the waste container and spray
into the container until all air is purged from the system and coating
material flows smoothly from the gun, without spitting.
6. Adjust the pump air pressure to produce the desired fluid pressure. The
pressure should be no more than is necessary to produce an even spray
pattern with graduated edges at a distance of approximately 30−40 cm
(12−16 in.).
Desired output pressure pump ratio = air pressure required
If you have a 57:1 pump, and you want an output pressure of 172 bar
(2500 psi) you would calculate the required air pressure as follows:
172 bar 57 = 3 bar (2500 psi 57 = 43.8 psi) air pressure required.
NOTE: If the fluid pressure is too high, excessive material consumption and
overspray will occur. If the fluid pressure is too low, spray pattern fingering
and uneven coating thicknesses will occur.
7. If using a fluid heater, turn on the heater only after all air is out of the
system and coating material is circulating freely.
WARNING: If using a fluid heater, always keep the coating material
circulating through the heater while it is on. Without a continuous flow
through the heater, the coating materials can cure inside the heater and
clog it. The heat could also cause solvents in the coating materials to
vaporize, expand, and damage the heater and other system equipment.
This could result in an explosion, causing property damage and personal
injury. Shut off the heater and continue circulating coating material through
the pump for 10−15 minutes before stopping the pump.
Changing Colors or Material
1. Flush the pump and system with a solvent or waterborne cleaning
solution compatible with the coating material used.
2. Clean the gun nozzle, suction strainer, and filter as necessary.
3. If changing material type, flush the pump and system again with a
flushing solution compatible with the new coating material.
4. Place the suction strainer into the new coating material. Open the filter
drain valve until the new coating is flowing out of the valve. Close the
valve.
5. Ground the spray gun against the side of the waste container and spray
into the container until all air is purged from the system and coating
material flows smoothly from the gun, without spitting.

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Shutdown
1. If a fluid heater is used, turn it off 10 to 15 minutes before shutting down
the pump. This prevents coating material from curing inside the heater.
2. Shut off the air supply to the pump.
3. Relieve the system hydraulic pressure by triggering the spray device(s)
or carefully opening a drain valve.
NOTE: Normally, you can leave the system filled with coating material
overnight. If the material contains solids that easily settle out, circulate
material through the system for several minutes before spraying. Do not
leave the system open to air. The coating material could cure and clog the
system. If the system will be shut down for more than a few days, flush it
and leave it filled with clean solvent or waterborne cleaning solution.
Maintenance
WARNING: Allow only qualified personnel to perform the following tasks.
Follow the safety instructions in this document and all other related
documentation.
WARNING: Stop the pump and relieve air and hydraulic pressures before
disconnecting air or fluid hoses, or before disassembling any equipment.
Daily
Do the following daily:
1. Make sure that all conductive equipment in the spray area, including the
pump and waste container, are securely connected to a true earth
ground.
2. Drain the air filter. Check the filter element and replace it if necessary.
Open the drop leg drain valve and drain collected moisture.
3. Fill the air lubricator.
4. Clean the fluid filter screen. Replace the screen as necessary.
5. Check the level of solvent fluid in the solvent chamber. Add more
solvent fluid as needed.
NOTE: Coating material leaking past the upper packing gland will
discolor the solvent fluid and cause its level to rise. A small amount of
leakage is normal. Drain and refill as needed.
The upper and lower packings are self-adjusting. If the solvent chamber
quickly fills then the upper packings are worn or damaged and need to
be replaced. Both upper and lower packings should be replaced at the
same time.
6. Flush the pump and system at each material change.

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As Needed Maintenance
SFlush the pump and system with a compatible flushing material.
SChange the solvent fluid regularly.
SClean the exterior of the pump.
SCheck all system grounds regularly.
Troubleshooting
WARNING: Allow only qualified personnel to perform the following tasks.
Follow the safety instructions in this document and all other related
documentation.
These troubleshooting procedures cover only the most common problems.
If you cannot solve a problem with the information given here, contact your
local Nordson representative for help.
General Troubleshooting
Refer to Air Motor Troubleshooting for problems specific to the air motor.
Problem Possible Cause Corrective Action
1. Pump fails to start or
stops while operating
and fails to restart
No compressed air supply, or air
pressure too low
Check the compressed air supply.
Adjust the air pressure as necessary.
Blockage in fluid system Check for flow from each component
and hose, working from the spray
device to the pump, as follows: Shut
off the air to the pump and relieve the
hydraulic pressure. Break the
connection. Turn on the air to the
pump. If the pump starts, the
blockage is in the component or hose
after the broken connection.
Air motor or air valve defective Rebuild or replace as necessary.
2. Pump strokes
irregularly when spray
gun is triggered
Air in hydraulic system Purge air from system. Refer to
Flushing on page 12.
Worn or clogged pump ball check
valve
Flush the system with a compatible
flushing material. If the problem
persists, rebuild the ball valves.
Worn packings Replace the pump packings.
Continued...

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Corrective ActionPossible CauseProblem
3. Pump operates, but
flow is restricted, or
pump surges
Air motor or valve leak Rebuild or replace as necessary.
Volume of compressed air is not
adequate
Check air supply hoses, filter, or
regulator for restrictions.
Blockage in fluid system Refer to Problem 1.
Coating material too viscous Check the material viscosity. Add
solvent to the material to lower the
viscosity.
Drain valve leaking Check drain valves for leaks.
Spray gun output exceeds system
capacity
Reduce the spray device nozzle or
fluid tip size. Reduce the number of
spray guns connected to the pump.
4. Pump fails to siphon
coating material
Blocked siphon strainer, rod, or
hose
Check and clean as necessary.
Air leak in siphon system. Check the siphon hose for leaks.
Break apart all connections in the
siphon system. Remove the old pipe
thread sealant from the threads and
apply new sealant before
reconnecting the fittings.
Coating material too viscous. Check material viscosity. Add
solvent to the material to lower the
viscosity.
Siphon hose too long, hose ID too
small, or strainer screen too fine
for coating material
Use the siphon hose shipped with
pump, or contact your Nordson
representative. Check the strainer
screen. If the strainer screen is
clogged with pigment, use a coarser
mesh screen or a strainer without a
screen.
Siphon ball check stuck Relieve pressure, remove siphon
hose, and push up on ball to free it.
If it problem continues, remove and
clean ball and seat.
5. Pump continues to
operate after spray
guns are shut off, or
after drain and
circulation valves are
closed.
Coating material supply low, pump
is siphoning air
Supply coating material to pump.
Drain valve or circulation valve
leaking
Check valves and clean or replace as
necessary.
Leaking ball check valve Clean or rebuild ball check valves.
Continued...

StediFlot57:1 Pump 17
Part 1601882-01
E2012 Nordson Corporation
Corrective ActionPossible CauseProblem
6. Pump does not stroke
when circulation valve
is opened
Clogged circulation valve, or
blockage in system
Open the circulation valve fully, then
close it partially. If the problem
continues, flush the system with a
compatible cleaning solution. Refer
to problem 1.
No compressed air supply, or air
pressure is too low
Check the air supply at the drop-leg
drain valve. Make sure the regulator
is working correctly.
7. Solvent chamber
overflows often
Upper packings worn Replace the packings.
8. Fading or narrowing of
the spray pattern
Compressed air pressure is too
low
Make sure the air pressure regulator
is working correctly. The pump air
motor requires at least 1.38 bar (20
psi) air pressure to operate. Increase
the air pressure. Check for a
restriction in the air supply line.
Blockage in hydraulic system Refer to problem 1.
Nozzles or fluid tips too large, or
too many spray guns connected to
system
Reduce the nozzle or fluid tip size, or
the number of spray guns connected
to the pump.
Spray gun nozzle plugging Remove the filter screen and inspect
it. If the screen is damaged, replace
it. If the screen is undamaged,
replace it with one with a smaller
mesh size.
9. Spray pattern has
tails of unatomized
coating material at the
outer edges
Low hydraulic pressure or partial
blockage in system
Increase the air pressure. Flush the
system with a compatible cleaning
solution. Refer to problem 1.
Material too viscous Add solvent to the coating material to
lower the viscosity.
Damaged nozzle or fluid tip Replace the nozzle or fluid tip.

StediFlot57:1 Pump
18
Part 1601882-01 E2012 Nordson Corporation
Air Motor Troubleshooting
These troubleshooting procedures cover only problems with the air motor.
See Figure 7 for item numbers.
Problem Possible Cause Corrective Action
1. Air is leaking from the
control piston into the
mufflers.
Control piston (5) is worn. Replace the control piston.
(Motor continues to run
but slows down.)
Lip seal (54) is worn. Replace the lip seal.
O-ring (58) or O-ring (59) is worn. Replace the O-rings.
Gasket (15) is defective. Replace the gasket.
2. Air blows out of the
lower motor housing
(74) drain hole.
Guide bushing (46) is worn. Replace the guide bushing.
3. Motor does not run,
air is leaking from the
control piston into the
mufflers.
Toggle (18) is no longer seated in
either the toggle bearing (19) or
the carrier (25).
Repair.
Connecting rod spring (62 or 65) is
broken.
Replace the spring(s).
4. Air motor fails to
perform as expected.
Insufficient air pressure or volume. Check compressor output, increase
size of air line if necessary.
Muffler is clogged. Replace the muffler(s).