Nordson 25B Reference guide

25B 4:1 Plated Steel Pump
Customer Product Manual
Document Number1044131-06
Issued 01/24
For parts and technical support, call the Industrial Coating
Systems Customer Support Center at [phone] or
contact your local Nordson representative.
This document is subject to change without notice.
Check http://emanuals.nordson.com for the latest version.
NORDSON CORPORATION • AMHERST, OHIO • USA

© 2024 Nordson Corporation
1044131-06
Contact Us
Nordson Corporation welcomes requests for information, comments, and inqui-
ries 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 2004. 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. All other trademarks are the property of their respective owners.
NOTE: This manual covers only the 4:1 version of
the 25B pump. Other versions are covered in the
following manuals:
2:1 Plated Steel 104330
16:1 Aluminum 1044132
16:1 Stainless Steel 1044133
27:1 Aluminum 1044134
27:1 Stainless Steel 1044135

i
Table of Contents
©2024 Nordson Corporation 1044131-06
Safety.............................................................................................................................................. 3
 ................................................................................................................................. 3
Dimensions and Weight ................................................................................................................. 3
Operating Sound Levels................................................................................................................. 3
 ............................................................................................................. 4
Operating Sound Levels.................................................................................................................. 4
Connections..................................................................................................................................... 4
Pump and Subassemblies .............................................................................................................. 5
Service Kits...................................................................................................................................... 5
Air Motor Service Kits .................................................................................................................... 5
Hydraulic Section Service Kits ...................................................................................................... 5
Packing Glands and Kits ................................................................................................................. 5
Recommended Spare Parts ........................................................................................................... 6
Adhesives, Sealants, and Lubricants ............................................................................................. 6
Solvent Chamber Fluid ................................................................................................................... 6
Options ........................................................................................................................................... 7
Safety ............................................................................................................................................. 1-1
Introduction................................................................................................................................... 1-1
 ...................................................................................................................... 1-1
Intended Use ................................................................................................................................ 1-1
Regulations and Approvals........................................................................................................... 1-1
Personal Safety ............................................................................................................................ 1-2
High-Pressure Fluids................................................................................................................... 1-3
Fire Safety .................................................................................................................................... 1-4
Halogenated Hydrocarbon Solvent Hazards............................................................................... 1-4
Action in the Event of a Malfunction ............................................................................................. 1-5
Disposal........................................................................................................................................ 1-5
Safety Labels.................................................................................................................................... 6
Description .................................................................................................................................... 2-1
Introduction ................................................................................................................................... 2-1
Pump Versions............................................................................................................................... 2-1
Packings....................................................................................................................................... 2-1
Pump Operation............................................................................................................................. 2-1
Suction Stroke .............................................................................................................................. 2-1
Pressure Stroke............................................................................................................................... 2
Plunger Lubrication.......................................................................................................................... 2
Dead-End and Circulating System Operation.................................................................................. 4
Options ............................................................................................................................................ 4
Installation..................................................................................................................................... 3-1
Mounting and Connections............................................................................................................ 3-1
Mounting....................................................................................................................................... 3-1
Grounding..................................................................................................................................... 3-2
Siphon and High Pressure Fluid Connections.............................................................................. 3-2
High Pressure Port:.................................................................................................................... 3-2
Compressed Air Connection......................................................................................................... 3-4
Installation Guidelines.................................................................................................................... 3-5
Installation Guidelines (con’t)......................................................................................................... 3-7
Operation and Maintenance......................................................................................................... 4-1
Introduction.................................................................................................................................... 4-1
System Check .............................................................................................................................. 4-1
Solvent Chamber Fill .................................................................................................................... 4-2
Flushing ..........................................................................................................................4-2
Frequency..................................................................................................................................... 4-2
Cleaning Solution for Flushing...................................................................................................... 4-2
System Flushing........................................................................................................................... 4-3
Routine Startup.............................................................................................................................. 4-5
Preparation................................................................................................................................... 4-5
Startup.......................................................................................................................................... 4-5
Routine Shutdown ........................................................................................................................ 4-6
Maintenance .................................................................................................................................. 4-7
Daily.............................................................................................................................................. 4-7
Weekly.......................................................................................................................................... 4-7
Every Four to Six Months ............................................................................................................. 4-8

©2024 Nordson Corporation
1044131-06
ii Table of Contents
As Needed.................................................................................................................................... 4-8
Troubleshooting............................................................................................................................ 5-1
Common Problems........................................................................................................................ 5-2
Minimizing Pressure Deviations..................................................................................................... 5-7
Air Supply ..................................................................................................................................... 5-7
Air Exhaust ................................................................................................................................... 5-7
Correcting Siphon Problems......................................................................................................... 5-7
Cavitation .................................................................................................................................... 5-7
Priming Problems........................................................................................................................ 5-8
󰀪 ................................................................................... 5-8
25B Air Valve and Air Motor Repair............................................................................................. 6-1
Introduction.................................................................................................................................... 6-1
Air Valve Repair............................................................................................................................ 6-1
Tools and Materials Required....................................................................................................... 6-1
Air Valve Removal ........................................................................................................................ 6-1
Air Valve Disassembly ................................................................................................................. 6-2
Snapper Rebuild.......................................................................................................................... 6-3
Air Valve Assembly...................................................................................................................... 6-4
Air Valve Installation .................................................................................................................... 6-5
Air Motor Repair ........................................................................................................................... 6-5
Tools and Materials Required...................................................................................................... 6-5
Preparation.................................................................................................................................. 6-5
Separating the Air Motor and Hydraulic Section.......................................................................... 6-6
Air Motor Disassembly ................................................................................................................ 6-6
Air Motor Disassembly (con’t) ..................................................................................................... 6-7
Piston Repair................................................................................................................................ 6-8
Piston Disassembly..................................................................................................................... 6-8
Piston Assembly.......................................................................................................................... 6-9
Air Motor Assembly....................................................................................................................... 6-9
Connecting the Air Motor and Hydraulic Section....................................................................... 6-10
Returning the Pump to Service.................................................................................................... 6-10
25B 4:1 Hydraulic Section Repair................................................................................................ 7-1
Introduction.................................................................................................................................... 7-1
Tools and Materials Required....................................................................................................... 7-1
Preparation................................................................................................................................... 7-1
Dismounting the Pump................................................................................................................ 7-1
Separating the Air Motor and Hydraulic Section.......................................................................... 7-2
Disassembly .................................................................................................................................. 7-3
Disassembly (con’t) ....................................................................................................................... 7-4
Cleaning, Inspection, and Parts Replacement............................................................................... 7-5
Ball Check Test............................................................................................................................. 7-5
Packing Gland Replacement....................................................................................................... 7-5
Type G Packing Gland Rebuild ................................................................................................... 7-6
Assembly...................................................................................................................................... 7-7
Assembly (con't) ........................................................................................................................... 7-8
...................................................................................................................................................... 7-8
Connecting the Air Motor and Hydraulic Section......................................................................... 7-8
Returning the Pump to Service..................................................................................................... 7-9
25B Air Motor and Air Valve Parts............................................................................................... 8-1
Parts .............................................................................................................................................. 8-1
Using the Illustrated Parts List...................................................................................................... 8-1
Air Motor Parts .............................................................................................................................. 8-2
Air Valve Parts .............................................................................................................................. 8-4
󰀪...................................................................................................................... 8-6
Air Motor and Air Valve Service Kits............................................................................................. 8-7
󰀪 .................................................................................................................................... 8-7
Air Motor Seal Kit ........................................................................................................................ 8-7
Air Valve Seal Kit......................................................................................................................... 8-7
Air Valve Crankshaft and Arm Kit ................................................................................................ 8-8
Options ......................................................................................................................................... 8-8
Air Motor Accessory Group ......................................................................................................... 8-8
.................................................................................................................................................... 8-9
Adhesives, Sealants, and Lubricants ......................................................................................... 8-9

©2024 Nordson Corporation
1044131-06
iii Table of Contents
25B 4:1 Plated Steel Hydraulic Section Parts ............................................................................ 9-1
Parts .............................................................................................................................................. 9-1
Using the Illustrated Parts List...................................................................................................... 9-1
4:1 Replacement Packing Glands ................................................................................................. 9-2
4:1 Type F Hydraulic Section Parts ............................................................................................... 9-4
4:1 Replacement Packing Glands ................................................................................................. 9-6
Packing Gland Materials and Applications .................................................................................. 9-6
4:1 Type F Hydraulic Section Parts ............................................................................................... 9-6
Pressure Ball Check Kit............................................................................................................... 9-6
Siphon Ball Check Kit.................................................................................................................. 9-7
Hydraulic Service Kits for Type A, D, F, and U Packings............................................................. 9-7
Hydraulic Service Kit for Type G Packings.................................................................................. 9-8
Options ......................................................................................................................................... 9-9
Wall Mounting/Siphon Accessory Kit........................................................................................... 9-9
Adhesives, Sealants, and Lubricants ........................................................................................ 9-10
Drawings...................................................................................................................................... 10-1
25B Pump Air Valve Parts .......................................................................................................... 10-2
25B 4:1 Hydraulic Section Parts................................................................................................. 10-3

©2024 Nordson Corporation
1044131-06
iv Table of Contents

i
Change Record
©2024 Nordson Corporation 1044131-06
Change Record
Revision Date Change
01 11/20 Initial Release
06 01/24 Updated Quantity of 3/8-16 nut (PN 984163), Images Updated

©2024 Nordson Corporation
1044131-06
ii Change Record

© 2024 Nordson Corporation  © 2024 Nordson Corporation 
Quick Reference – 25B 4:1 Plated Steel PumpQuick Reference – 25B 4:1 Plated Steel Pump
Service Kits
Refer to 25B 4:1 Plated Steel Pump Manual 1044131 for complete service and parts information.
For parts and technical support call [phone]
Introduction
Use this section for quick access to the following information on the 25B 4:1 Plated Steel
pump:
• 
• service kits and packing glands
• recommended spare parts
• adhesives, sealants and lubricants used for service
• 
• options
• 
Refer to the following sections for more information:
Safety, Description, Installation, Operation, and Troubleshooting
Air Motor and Hydraulic Section Repair
Air Motor and Hydraulic Section Parts
CE Approvals, Solvent Chamber Fluids, Air Lubricator Information, Parts Posters
Specications
Dimensions and Weight
Dimension/Weight 25B 4:1
Height 688 mm (27.10 in.)
󰀪 290 mm (11.42 in.)
Depth (front to back, in wall mounting bracket) 162 mm (6.40 in.)
Weight 2.8 kg (46 lbs)
Operating Sound Levels
Air Pressure bar (psi) Sound Level dB A (maximum) Sound Level dB C (maximum)
7 (100) 68 72
4.1 (60) 68 71

© 2024 Nordson Corporation  © 2024 Nordson Corporation 
Air and Fluid Specications
Fluid to
Air Ratio
Max. Air
Pressure
bar
(psi)
Max. Fluid
Working
Pressure
bar (psi)
Fluid Flow, liters/min (gpm)
Cycles per Liter
(Gallon)
Liters (Gallons) per
Cycle
at 15 cpm at 30 cpm at 60 cpm
4:1 7
(100)
28
(400)
2.80
(0.75)
5.70
(1.50)
11.40
(3.00)
5.20
(20.00)
0.195
(0.050)
Operating Sound Levels
Air
Pressure
Strokes Per Minute
20 40 60 80 100
2.7 bar
(40 psi)
0.43 l/sec
(0.91 cfm)
0.88 l/sec
(1.87 cfm)
0.76 l/sec
(2.80 cfm)
1.75 l/sec
(3.70 cfm)
2.22 l/sec
(4.70 cfm)
4.1 bar
(60 psi)
0.71 l/sec
(1.50 cfm)
1.42 l/sec
(3.00 cfm)
2.12 l/sec
(4.50 cfm)
2.83 l/sec
(6.00 cfm)
3.54 l/sec
(7.50 cfm)
5.5 bar
(80 psi)
0.90 l/sec
(1.90 cfm)
1.77 l/sec
(3.75 cfm)
2.64 l/sec
(5.60 cfm)
3.54 l/sec
(7.50 cfm)
4.43 l/sec
(9.40 cfm)
7 bar
(100 psi)
1.06 l/sec
(2.25 cfm)
2.12 l/sec
(4.50 cfm)
3.21 l/sec
(6.80 cfm)
4.25 l/sec
(9.00 cfm)
5.33 l/sec
(11.30 cfm)
Connections



Fluid hose: high pressure airless hose


WARNING:


dampen vibrations.

© 2024 Nordson Corporation  © 2024 Nordson Corporation 
Part Number Quick Reference
Pump and Subassemblies
Part Description
247537 Pump, 25B, 4:1, steel, Type U packings
1077621 Pump, 25B, 4:1, steel, Type F packings
245546 • Motor, air, 25B
323001 • • 2.8 kg (46 lbs)
247535 • Pump, hydraulic, 25B, 4:1, steel, Type U packings
1077605 • Pump, hydraulic, 25B, 4:1, steel, Type F packings
Service Kits
Air Motor Service Kits
Part Description Note
323099 MUFFLER assembly A
106103 SERVICE KIT, seal, air valve A
106314 SERVICE KIT, crankshaft and arm (air valve) A
106274 SERVICE KIT, seal, air motor, 25B A
NOTE: A. Refer to Air Motor Parts in Part D1xx for a parts breakdown
Hydraulic Section Service Kits
Part Description
106309 SERVICE KIT, pressure check, 2:1, 4:1
106308 SERVICE KIT, siphon check, 25B
NOTE: A. Refer to “25B 4:1 Plated Steel Hydraulic Section Parts” on page 9-1 for a parts breakdown.
Packing Glands and Kits
Refer to the Packing and Solvent Chamber Fluid Selection Guidexx included in the
Appendix of this manual for information on selecting the correct packing glands and

Packing Glands for 4:1 25B Pumps
Packing Gland Type A Type D Type F Type G Type U
Upper Packing — — — 248049 (A) —
Hydraulic
Service Kits 106360 (B) 714898 (B) 106303 (B) 106390 (C) 335379 (B)
NOTE: A. Complete packing glands with housings and external O-ring.
B. Refer to page D 2-7 for contents of hydraulic service kits
C. Type G hydraulic service kit includes parts to rebuild upper packing gland and replace lower packings and
hydraulic section O-rings. Does not include upper packing gland housing or internal retaining rings. Refer to
“25B 4:1 Plated Steel Hydraulic Section Parts” on page 9-1, for more information

© 2024 Nordson Corporation  © 2024 Nordson Corporation 
Recommended Spare Parts
Keep the following parts in inventory to avoid unplanned downtime. Quantities listed
support a single pump. Adjust order quantities based on the number of pumps in service.
Part Description Quantity Note
106103 SERVICE KIT, seal, air valve 1
106314 SERVICE KIT, crankshaft and arm (air valve) 1
323053 GLAND, air motor 1
323022 STEM, ball 1
106274 SERVICE KIT, seal, air motor, 25B 1
106309 SERVICE KIT, pressure check, 2:1, 4:1 1
106308 SERVICE KIT, siphon check, 25B 1
246205 PLUNGER, hydraulic, 25B, 4:1 1
- - - - - PACKING glands AR A
NOTE: A. Order upper glands or kits. Quantity to stock for one pump depends on coating material used, pump cycle
rate, and operating schedule. Replace both packing glands at the same time if possible. Refer to “Packing Glands
and Kits” on page 5 in this section for part numbers.
AR: As Required
Adhesives, Sealants, and Lubricants
Use these adhesives, sealants, and lubricants for maintenance and repairs.
Part Description Quantity
900439 ADHESIVE, threadlocking (Loctite High Temp 271) 1
900481 ADHESIVE, pipe/thread/hydraulic sealant (Loctite High Temp SS567) 1
1612251 LUBRICANT, O-ring, Parker (Parker O-Lube), 2 oz 1
900252  1
900236 SEALANT, paste, PTFE, 1 pint 1
900214 OIL, Vitalizer, 1 pint (air lubricator) 1
900215 OIL, Vitalizer, 1 quart 1
900216 OIL, Vitalizer, 1 gallon 1
900217 OIL, Vitalizer, 5 gallons 1
Solvent Chamber Fluid
Solvent
chamber uid is not shipped with the pump, since the pump can be used with either
water-based or solvent-based coating materials. Refer to the Pump Packing and Solvent
Chamber Fluid Guide included with this manual for application information.
Part Description
248831 FLUID, type-S, pump chamber, one quart
900255 FLUID, type-K, pump chamber, one quart
140029 FLUID, type-T, pump chamber, one quart
244854 

© 2024 Nordson Corporation  © 2024 Nordson Corporation 
Options
Part Description Note
1024722 

brackets and fasteners, and lubricating oil. Refer to 25B
Air Motor and Air Valve Parts for the kit parts list
246730 KIT, wall mount/siphon accessory, 25B, 2:1, 4:1
Kit contains wall mounting bracket and fasteners; solvent

25B 4:1 Plated Steel Hydraulic Section
Parts for the kit parts list
244777 SERVICE KIT, circulating, single
Single circulation valve; drain valve, hose, and rod, and

with kit.
244779 SERVICE KIT, circulating, dual
Two circulation valves; two drain valves, hoses, and

supplied with kit.
166930 
poppet

pump motoring. See Note.
338443 
brass, poppet

pump motoring. See Note.
712013 
brass, ball

pump motoring. See Note
NOTE: 

© 2024 Nordson Corporation  © 2024 Nordson Corporation 

1-1
Safety
© 2024 Nordson Corporation 1044131-06
Section 1
Safety
Introduction

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.
Qualied Personnel
Equipment owners are responsible for making sure that Nordson equipment is installed,

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:
• using incompatible materials
• 
• removing or bypassing safety guards or interlocks
• using incompatible or damaged parts
• using unapproved auxiliary equipment
• operating 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.

© 2024 Nordson Corporation
1044131-06
1-2 Safety
Personal Safety
To prevent injury follow these instructions.
• 
• Do 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.
• Keep clear of moving equipment. Before adjusting or servicing moving equipment,
󰀨
Lock out power and secure the equipment to prevent unexpected movement.
• 󰀨
pressurized systems or components. Disconnect, lock out, and tag switches before
servicing electrical equipment.
• While 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.
• If 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

• Obtain and read Safety Data Sheets (SDS) for all materials used. Follow the
manufacturer’s instructions for safe handling and use of materials, and use
recommended personal protection devices.
• Make sure the spray area is adequately ventilated. To 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.

© 2024 Nordson Corporation 1044131-06
1-3
Safety
High-Pressure Fluids



death. Fluids penetrating the skin can also cause toxic poisoning.
󰀨

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:
WARNING:Any injury caused by high pressure liquid can be serious. If you are injured
or even suspect an injury:
• Go to an emergency room immediately.
• Tell the doctor that you suspect an injection injury.
• Show them this card
• Tell them 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


the wound. If the injected paint contains acrylic latex and titanium dioxide that damage

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.

© 2024 Nordson Corporation
1044131-06
1-4 Safety
Fire Safety

• 
equipment and workpiece grounding devices regularly. Resistance to ground must not
exceed one megohm.
• Shut down all equipment immediately if you notice static sparking or arcing. Do not

• 
used or stored. Do not heat materials to temperatures above those recommended
by the manufacturer. Make sure heat monitoring and limiting devices are working
properly.
• Provide adequate ventilation to prevent dangerous concentrations of volatile particles
or vapors. Refer to local codes or your material SDS for guidance.
• 
󰀨
• 󰀨
󰀨
exhaust fans.
• 󰀨
cleaning, or repairing electrostatic equipment.
• Clean, maintain, test, and repair equipment according to the instructions in your
equipment documentation.
• Use 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 
Fluorine F “Fluoro-”
Chlorine Cl “Chloro-”
Bromine Br “Bromo-”
Iodine I “Iodo-”
Check your material SDS 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.

© 2024 Nordson Corporation 1044131-06
1-5
Safety
Action in the Event of a Malfunction
󰀨
and perform the following steps:
• Disconnect and lock out system electrical power. Close hydraulic and pneumatic
󰀨
• Identify 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.

© 2024 Nordson Corporation
1044131-06
6Safety
Safety Labels
Table B 1-1 contains the text of the safety labels on the pump. The safety labels are
provided to help you operate and maintain your pump safely. See Figure B 1-1 for the
location of the safety labels
NOTE:Item 3 is included with aluminum pumps only.
Table B 1-1 Safety Labels
Item Part Description
1 181119
WARNING
• HIGH PRESSURE DEVICE
Read instruction manual before operation and observe all warnings.
• INJECTION HAZARD
Airless spray painting equipment can cause serious injury if the spray penetrates the skin. Do not
point the gun at anyone or any part of the body. In case of penetration, adequate medical aid must
be immediately obtained.
• COMPONENT RUPTURE
This system is capable of producing bar ( psi) pressure. To avoid rupture and injury, do
not operate this pump at a pressure higher than the rated maximum working pressure of any
component in the system (including but not limited to spray guns, hose, hose connections and
heaters).
• FIRE
Static voltage is developed by airless spraying. The pump, associated system, and object being

• SERVICING
󰀨

2 181147 MAXIMUM INPUT 6.9 BAR (100 PSI)
3
246890
(Aluminum
pumps
only)
WARNING
Do not use halogenated hydrocarbon solvents in this system, it contains aluminum parts
and may explode. Cleaning agents, coatings, paints or adhesives may contain halogenated
hydrocarbon solvents. Don’t take chances, consult your material supplier to be sure