Nordson A7A Reference guide

A7A Quattro Modular
Automatic Spray Gun
Customer Product Manual
Document Number1602111-03
Issued 07/22
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

© 2022 Nordson Corporation
1602111-03
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. All other trademarks are the property of their respective owners.
Table of Contents
Safety............................................................................................ 1
Introduction................................................................................... 1
Qualied Personnel...................................................................... 1
Intended Use................................................................................ 1
Regulations and Approvals........................................................... 1
Personal Safety............................................................................ 2
High-Pressure Fluids................................................................... 3
Fire Safety.................................................................................... 4
Halogenated Hydrocarbon Solvent Hazards............................... 4
Action in the Event of a Malfunction............................................. 5
Disposal........................................................................................ 5
Description................................................................................... 6
Nozzles......................................................................................... 6
Specications ............................................................................... 6
Gun Module Components and Operation..................................... 8
Installation.................................................................................... 9
Mounting....................................................................................... 9
Fluid Connections......................................................................... 9
Trigger Air Connection................................................................ 10
Nozzle Installation ...................................................................... 10
Maintenance............................................................................... 10
Troubleshooting ........................................................................ 11
Spray Gun Repair ...................................................................... 12
Disassembly............................................................................... 12
Cleaning and Inspection............................................................. 12
Assembly.................................................................................... 12
Parts............................................................................................ 14
Options....................................................................................... 16
Service Kits ................................................................................ 16
Service Parts.............................................................................. 16
Options....................................................................................... 17
Service Kits ................................................................................ 17
Service Parts.............................................................................. 17

i
Change Record
© 2022 Nordson Corporation 1602111-03
Change Record
Revision Date Change
02 8/18 Revised ATEX markings.
03 07/22 Added CE and UK symbols.

© 2022 Nordson Corporation
1602111-03
ii Change Record

1
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
Introduction
Read and follow these safety instructions. Task- and equipment-specic 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.
Qualied Personnel
Equipment owners are responsible for making sure that Nordson equipment is installed,
operated, and serviced by qualied personnel. Qualied 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:
• using incompatible materials
• making unauthorized modications
• 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.
Safety

2A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Personal Safety
To prevent injury follow these instructions.
• Do not operate or service equipment unless you are qualied.
• 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,
shut o󰀨 the power supply and wait until the equipment comes to a complete stop.
Lock out power and secure the equipment to prevent unexpected movement.
• Relieve (bleed o󰀨) hydraulic and pneumatic pressure before adjusting or servicing
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
identied and corrected.
• 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.

3
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
High-Pressure Fluids
High-pressure uids, unless they are safely contained, are extremely hazardous. Always
relieve uid pressure before adjusting or servicing high pressure equipment. A jet of
high-pressure uid can cut like a knife and cause serious bodily injury, amputation, or
death. Fluids penetrating the skin can also cause toxic poisoning.
If you su󰀨er a uid injection injury, seek medical care immediately. If possible, provide a
copy of the SDS for the injected uid 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:
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
substance hit something on its way in and deected causing more damage, and many
other variables including skin microora 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 ourish. 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.

4A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Fire Safety
To avoid a re or explosion, follow these instructions.
• Ground all conductive equipment. Use only grounded air and uid hoses. Check
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
restart the equipment until the cause has been identied and corrected.
• Do not smoke, weld, grind, or use open ames where ammable materials are being
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.
• Do not disconnect live electrical circuits when working with ammable materials. Shut
o󰀨 power at a disconnect switch rst to prevent sparking.
• Know where emergency stop buttons, shuto󰀨 valves, and re extinguishers are
located. If a re starts in a spray booth, immediately shut o󰀨 the spray system and
exhaust fans.
• Shut o󰀨 electrostatic power and ground the charging system before adjusting,
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 Prex
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.

5
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
Action in the Event of a Malfunction
If a system or any equipment in a system malfunctions, shut o󰀨 the system immediately
and perform the following steps:
• Disconnect and lock out system electrical power. Close hydraulic and pneumatic
shuto󰀨 valves and relieve pressures.
• 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.

6A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Description
The Quattro A7A automatic spray gun is a high-cycle, air-operated, modular airless spray
gun with four gun modules supplying one manifold and nozzle. It can be used for general
nishing as well as ultra-high speed applications using solventborne or waterborne
coatings where quick color changes are required.
Nozzles
Nozzles are not included with the spray gun. For information on Nordson airless nozzles
and help in choosing the correct nozzle for your application, contact your Nordson
representative.
Gun Modules
Nozzle Nut
Quattro Manifold
Fluid/Air/Mounting
Manifolds
Fluid Fittings
Air Fittings
Figure 1 A7A Quattro Spray Gun
Specications
Properties Specication
Maximum uid pressure 103 bar (1500 psi)
Air trigger requirements 2.75-8.27 bar (40-120 psi)
Fittings
Fluid air supply and return 1/2-20 JIC x 1/4-in. NPT
Trigger air 1/4-in. tubing x 1/8-in. NPT
Dimensions See Figure 2
Weight 5.21 kg (11.5 lbs)
Mounting 13-mm (1/2-in.) round bar

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A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
79.25 mm
(3.12 in)
149.35 mm
(5.88 in)
136.65 mm
(5.88 in)
Figure 2 A7A Quattro Spray Gun Dimensions
Figure 3 A7A Quattro Spray Gun ATEX Markings

8A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Gun Module Components and Operation
The spray gun consists of a Quattro manifold and four gun modules, each with a uid/air/
mounting manifold. This sectional view shows the main components of the gun modules.
1
2
3
4
5
8
6
7
9
10
0.016-0.023 in.
Figure 4 A7A Quattro Modular Spray Guns
1. Air cylinder
2. Compression spring
3. Piston assembly
4. Gun body
5. Packing cartridge
6. Ball tip
7. Seat
8. Seat retainer
9. Manifold
10. Nozzle nut
The packing cartridge (5) stem connects the piston (3) to the ball tip (6). When the gun is
triggered on, air pressure pushes against the bottom of the piston, lifting the ball tip away
from the seat (7) and allowing coating material to ow through the seat and nozzle.
When the gun is triggered o󰀨, the air pressure forcing the piston up is released. The
compression spring (2) and packing cartridge spring force the ball tip against the seat,
stopping the ow of coating material out of the nozzle.
The packing cartridge seals prevent coating material from entering the air cylinder. If the
packing cartridge seals start to leak, coating material will ow out the weep holes in the
gun body.

9
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
Installation
WARNING:Allow only qualied personnel to perform the following tasks. Follow the
safety instructions in this document and all other related documentation.
Figure 5 shows the uid and air system for one color of coating material in a typical
installation.
WARNING:Ground all electrically conductive equipment in the system. Use only
grounded uid and air hoses.
Trigger air supply
1
12
5
4
2
6
3
11
8
7
9
10
7
7
1/2-20 JIC Fluid Fittings
1/8-in. Trigger Air Fitting
Figure 5 Typical Circulating System
1. Pump
2. Heater
3. Filter
4. Solenoid valve
5. Air regulator
6. Spray gun
7. Ball valves
8. Circulation valve
9. Drain o󰀨 rod
10. Waste container
11. Coating supply
12. Siphon hose and rod
Mounting
Slide a 13-mm (1/2-in.) round mounting bar through the holes in the gun module
manifolds, orient the gun as desired, and tighten the square head screws.
Fluid Connections
WARNING:In the uid supply line, install an approved pressure relief device set to the
lowest maximum working pressure of all system components. The uid hoses must have
a minimum burst pressure greater than the pressure relief device setting.
The spray gun uid ttings have 1/2- 20 JIC threads. Connect the uid supply and return
hoses to the ttings. Either tting can be used for supply or return.

10 A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Trigger Air Connection
Connect 1/8-inch tubing from a solenoid valve to the trigger air tting on the manifold.
For applications faster than 600 cycles per minute, install the optional quick-exhaust
valve at the air inlet. To do this, remove the air tting and install a 1/4-in. NPT nipple in
the manifold, then install the quick-exhaust valve on the nipple, and the air tting in the
quick-exhaust valve.
Nozzle Installation
Remove the nozzle nut from the end of the gun. Install your nozzle in the nozzle nut, then
screw the nut onto the gun. Tighten the nozzle nut securely.
Maintenance
Flush the gun periodically to keep it clean and free of contaminants. As required,
disassemble and clean the gun modules and replace any worn parts.
NOTE:Make sure the nozzle and seat sealing surfaces are clean before installing the
nozzle.
Make sure the trigger air is clean and dry. If you are operating the gun at high cycle rates
for long periods of time, install an air lubricator in the air supply line. This will extend the
life of the air piston seal.

11
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
Troubleshooting
WARNING:Allow only qualied personnel to perform the following tasks. Follow the
safety instructions in this document and all other related documentation.
These procedures cover only the most common problems. If you cannot solve the
problem with the information given here, contact the Nordson Industrial Coating Systems
Customer Support Center at (800) 433- 9319 or your local Nordson representative for
help.
Problem Possible Cause Corrective Action
1. Leaking around
nozzle or nozzle
retaining nut
Dirty or damaged nozzle
or seat sealing surfaces
Tighten the nozzle nut. If the leak persists, relieve system
pressure. Remove the nozzle nut and clean the nozzle and seat
sealing surfaces. If the leak persists, replace the nozzle or seat
(the ball tip and seat are a matched set and must be replaced
together).
2. Leaking from weep
holes Worn packing cartridge Replace the packing cartridge with the appropriate kit. Refer to Parts.
3. Spitting
Dirty or worn ball and
seat Clean or replace the ball and seat.
Actuating or trigger air
lines too long Mount the solenoid on or as close as possible to the gun.
Air trapped in uid
system
Purge air from system by opening the drain valve until no air
bubbles are seen, or spraying until spitting stops.
Make sure the pump is not siphoning air into the uid system.
4. On/O󰀨 cycle
response poor or
gun not opening or
closing
Air piston assembly worn
or out of adjustment Adjust or replace the air piston assembly.
Low air pressure to the
solenoid valve Increase the air pressure to between 2.7- 4.1 bar (40- 60 psi).
Trigger air lines too long Mount the solenoid on or as close as possible to the gun.
Fluid pressure too high Reduce the uid pressure. The guns will not close if their
maximum working pressure is exceeded.

12 A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Spray Gun Repair
WARNING: Allow only qualied personnel to
perform the following tasks. Follow the safety
instructions in this document and all other related
documentation.
Disassembly
1. See Figure 6. Flush the spray gun (1) with clean solvent
or cleaning solution.
2. Relieve the system uid and air pressure.
3. Remove the nozzle nut (22) and nozzle.
4. For each gun module:
a. Remove the air cylinder (4), gasket (5), and
compression spring (6).
b. Hold the packing cartridge (11) stem with a wrench
and remove the lock nut (7).
c. Unscrew the piston assembly (8) from the stem and
separate the seal nut, O-ring and piston (8A, 8B, 8C).
d. Remove the screws (17, 18), and the gun body (10)
from the manifold (16).
e. Push the packing cartridge (11) out of the body.
f. Hold the packing cartridge stem with one wrench
while unscrewing the ball tip (12A) from the stem with
another wrench.
g. Remove the large O-ring (13), seat retainer (14), seat
(12B), and small O-ring (15) from the manifold.
5. If necessary, remove the screws (19) and manifold (20)
from the gun body.
6. Remove the three O-rings (15) from the body.
Cleaning and Inspection
1. Clean the wetted parts with a compatible cleaning
solution.
2. The ball tips and seats are matched sets. If either are
worn or damaged, replace both.
3. Inspect the piston seal (8C). If it is worn or damaged
replace the piston (8).
4. Inspect all gaskets and O-rings. Replace any that are
damaged, using the service kit listed in Parts.
WARNING: Shut o󰀨 the uid pump and relieve the
system uid pressure before disconnecting the gun
module from the spray gun. High pressure uid is
dangerous and can cause injection injuries.
5. If coating material was leaking from the weep holes in
the gun bodies, replace the packing cartridges.
Assembly
1. If removed, install three O-rings (15) into the grooves in
the gun body
2. Install the manifold (20) on the gun body (10) and
tighten the screws (19) securely.
3. Assemble each gun module as follows:
a. If removed, install the O-ring (9) in the internal groove
in the body (10).
b. Apply VC-3 thread-locking compound to the bottom
threads of the packing cartridge (11) stem.
c. Screw the ball tip (12A) onto the packing cartridge
stem and tighten securely.
d. Push the packing cartridge into the gun body.
e. Install the O-ring (15), seat (12B), and seat retainer
(14) in the manifold (16).
f. Install the O-ring (13) on the seat retainer.
g. Install the body onto the manifold and tighten the
screws (17, 18) securely.
h. Thread the piston assembly (8) onto the packing
cartridge stem until it rests against the gun body.
i. See Figure 4. Thread the lock nut (7) part way down
the stem. Turn the piston assembly counterclockwise
1/2 to 3/4 turn, until it is 0.016- 0.023 inches from
the gun body. Thread the lock nut down against the
piston assembly.
j. Apply a drop of VC-3 thread-locking compound to
the lock nut threads. Hold the packing cartridge stem
with a small wrench while tightening the lock nut
against the piston assembly.
k. Install the compression spring (6) on top of the
piston.
l. Install the gasket (5) and air cylinder (4). Install the
screws (2) and lockwashers (3) and tighten the
screws securely.
4. When all gun modules have been rebuilt, install the
nozzle in the nozzle nut (21), then thread the nozzle nut
onto the manifold and tighten it securely.

13
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
2
3
4
6
9
7
8
8A
8B
8C
5
19
2
3
1
15
12A
12B
15
10
11
11A
13
14
16
21
17
18
1
20
SERVICE NOTES
Apply VC-3 thread-locking
compound to threads before
installing ball tip.
Apply VC-3 thread-locking
compound to threads before
tightening.
Apply pipe thread adhesive/
sealant (Loctite High Temp
SS567 or equivalent ) to
threads before installing.
1
2
3
Figure 6 A7A Quattro Spray Gun Repair

14 A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Parts
To order parts, call the Nordson Industrial Coating Systems Customer Support Center at
[phone] or contact your local Nordson representative.
Item Part Description Quantity Note
1 1601975 GUN, A7A, Quattro, stainless steel, LBS 1
2 981140 • SCREW, llet head, #10- 32 x 1.00 in., slotted, zinc 16
3 983120 • WASHER, lock, split, #10, steel, nickel 16
4 - - - - - - • CYLINDER, air 4
5 153031 • GASKET, gun, H20 4 A
6 342279 • SPRING, compression, 0.75 x 0.72 x 0.06 in., stainless steel 4
7 702118 • NUT, lock, #10- 32, upper 4 A
8 138737 • PISTON, H20/A7A H.P. assembly 4 A
8A - - - - - - • • NUT, seal, lock 1 A
8B 940090 • • O-RING, Viton, 0.208 ID x 0.070 in. wide, brown 1 A
8C - - - - - - • • PISTON 1 A
9 940157 • O-RING, Viton, black, 0.562 x 0.688 in. 4 A
10 - - - - - - • BODY, gun 4
11 1039171 • CARTRIDGE, packing, protective coating 4
11A 940134 • • O-RING, Viton, 0.438 x 0.563 x 0.063 in. 1
12 320019 • BALL and seat, A7A, nickel 4 B
12A - - - - - - • • BALL TIP 1 B
12B - - - - - - • • SEAT 1 B
13 940174 • O-RING, Viton, black, 0.688 x 0.813 in. 4 A
14 134975 • RETAINER, seat, A7A 4
15 940105 • O-RING, PTFE, 0.250 x 0.375 x 0.06 in. 16 A
16 - - - - - - • MANIFOLD, assembly, Quattro, A7A 1
NS 248932 • • PLUG 2
NS 900013 • • BALL, 440 stainless steel, 0.125 in., 100 2
17 981975 • SCREW, socket, cap, 10- 32 x 1.25 in. 8
18 981824 • SCREW, socket, 10- 32 x 0.875 in. 4
19 981847 • SCREW, socket, 10- 32 x 1.625, zinc 16
20 1054583 • MANIFOLD, A7A 2
21 152496 • NUT, retaining 1
22 981405 • SCREW, square, set, 3/8- 16 x 0.750 in., cup, zinc 4
23 972029 • CONNECTOR, male, 37, 1/2- 20 x 1/4 in. NPT, stainless steel 8
24 972716 • CONNECTOR, male, 1/4 in. tube x 1/8 in. NPT 4
25 331475 • PIN, dowel, 0.250 x 0.625 in., H & G 2
NS 247646 • CARD, medical alert, injection 1
NS 152999 • WRENCH 1
NS 901905 • BRUSH 1
NS 901911 • WRENCH, adjustment, module 1
NOTE: A. Included in 1072408 Service Kit, Rebuild, Modular A7A Guns.
B. To replace the ball and seat, order kit 337305.

15
A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation 1602111-03
1
2
3
4
6
7
8A
8B
8C
9
5
15
24
23
20
22
19
10
11
11A
13
14
12A
12B
15
25
16
21
20
8
Figure 7 A7A Quattro Gun Parts

16 A7A Quattro Modular Automatic Spray Gun
© 2022 Nordson Corporation
1602111-03
Options
Part Description Note
159146 Mounting bar, gun, universal 46-cm (18-in.)
901262 Quick exhaust valve
973000 Nipple, steel, schedule 40, 1/8 in. NPT, 0.75 in. long A
NOTE: A. Use to install quick-exhaust valve.
Service Kits
Part Description Note
1072408 SERVICE KIT, rebuild, modular A7A guns A
337305 KIT, ball and seat, nickel B
NOTE: A. Order four kits to rebuild all four gun modules.
B. Used on single gun only.
Service Parts
Part Description Note
900424 COMPOUND, thread lock, VC-3
900481 ADHESIVE, pipe thread/hydraulic sealant